George E. Smith

Zierler:

OK. This is David Zierler, oral historian for the American Institute of Physics. It is June 23rd, 2020. It is my great pleasure to be here with Professor George E. Smith. George, thank you so much for being with me today.

Smith:

I’m quite happy to be so, if I can contribute.

Zierler:

[laugh] All right, George, so to start, would you please tell me your title and your institutional affiliation?

Smith:

I am a professor in the philosophy department of Tufts University for the last 43 years.

Zierler:

[laugh] And now let’s take it back even farther than 43 years. Tell me about where you come from. Let’s start with your parents. Where are your parents from?

Smith:

From East Tennessee, the part that did not leave the Union. My father grew up on a farm, much of which got covered by Norris Lake. My great-grandmother was Cherokee. So by American legal standards, I’m Cherokee, but I find that a piece of humor especially because I did not learn of her being Native American until my father’s funeral.

My mother is from downtown Knoxville in the era of James Agee. They moved to Cincinnati because my father, a former athlete, was hired by Palm Beach and moved to Cincinnati, so I grew up in Cincinnati. In fact, Tom Kuhn was born in Cincinnati, but he was a good deal older than I.

OK. So what were your parents’ professions? Starting with your dad, what did your dad do for a living?

Smith:

He was a sales manager for Palm Beach Company and then for a made-to-measure clothing firm later in his life when he left Palm Beach because they would not hire a Jewish friend of his. And he, as a matter of principle, [laugh] felt he couldn’t work there, which doesn’t say much about his racial attitudes being a Southerner. But it does say something about his principles.

My mother ended up as a bookkeeper. She did not graduate from high school. She went to what was called business school where she learned to keep books. But she was rather good at it; good enough that she ended up being chief accountant at Clopay Corporation by the time she was 60. And she was very good with numbers.

They were both — judging — looking back on it now, you know, many, many years’ perspective, they were both very, very smart people with very limited education. My father had two years at University of Tennessee before the Depression forced him out of that. And my mother, as I say, never finished high school but was good enough in working with numbers. And I certainly learned to work with numbers very early. She also taught me to touch-type as a 4-year-old.

Zierler:

So your sense with your parents is with better opportunities, they would’ve pursued higher education?

Smith:

Oh, yes, my father definitely. I became somewhat of a fulfillment for him. And he was very, very pleased at — both when I went to Yale, and then years later when I got my PhD from MIT, he made sure he was there on both occasions, so, yes.

Zierler:

And, George, when did you enter the scene? What year were you born?

Smith:

1938.

Zierler:

Now do you have memories of World War II?

Smith:

I have very distinct memories of Sunday, December 7th, because the day before was my mother’s birthday. And they were having a small birthday party when suddenly they said, “Quiet everyone,” and turned the radio on, and Pearl Harbor. So, yes, I have very distinctive memories from World War II all over the place; the huge amount of propaganda, anti-German and anti-Japanese propaganda under which I grew up.

Oak Ridge abuts my grandfather’s farm. It was a mystery of World War II. I was actually in Knoxville the day Hiroshima was announced, and everybody — I learned of it from the Knoxville News Sentinel, announcing the atom bomb and —

Zierler:

Was it known that Oak Ridge was so centrally involved in the production of atomic weapons?

Smith:

Nobody had any idea what was going on [laugh] at Oak Ridge until that day. And it was immediately announced and overstated that the bomb was built there, which wasn’t true. It led me — in the 1960s, I had a chance to become a consultant for Oak Ridge, and I did so for the next 20 years. Part of the reason I did so [laugh] was because I was so fascinated as a kid.

Zierler:

Did you go to public school growing up?

Smith:

I went to public school. But one of the public schools, Walnut Hills High School in Cincinnati, is a six-year exam school with required Latin. And we were one of six high schools in the United States that were guinea pig for the AP program. So I entered Yale with a year and a half of college credits from my AP classes at Walnut Hills. And that basically transformed my life as I came with two years of calculus, having learned it from Courant, Differential & Integral Calculus, first, Volume I.

I came with a very solid physics background. I came with six years of Latin including AP Latin, English AP, and History AP. And it put me in a position at Yale — well, I was in Directed Studies at Yale. But it put me in a position by my sophomore year, I was taking a couple of graduate courses — low-level graduate courses. Don’t let me exaggerate.

Zierler:

George, how would you describe your childhood socio-economically? Was it pretty middle-class?

Smith:

Lower-middle, middle-class. We weren’t — we were never wealthy, but we were never hurting. My parents encouraged me to start earning money very young, so I had jobs from the time I was roughly 12 on. You know, they were children of the Depression. [laugh]

Zierler:

And, George, was your childhood integrated or mostly segregated, either, you know, de facto or just sort of, you know, officially?

Smith:

More complicated than you might think. My grade school happened to also include a school for hard of hearing, so there were African Americans there, and there was one African American in my sixth grade class. Something happened to me while I was in grade school. It’s hard to explain. Jackie Robinson entered the Major Leagues. I was already an intense baseball fan.

I’ll simply describe the day. It’s quite memorable. The Dodgers, Brooklyn Dodgers, were in Cincinnati on a weekday in the summer, so I wasn’t in school. And my parents had already taught me by 1947 at age 9 how to get around town on the public transportation by myself. So I went to the game because I wanted to see what all the fuss about Jackie Robinson was about. And I had been to games by myself before, but never — Cincinnati didn’t have a very good team, and the Crosley Field was usually very far from sold-out.

That day, there were about 20,000 people, and almost all of them African-American. And as a kid, 9-year-old, walking around the ballpark because I didn’t like to sit once I got in Crosley Field, I liked to walk around and see things from different angles when I was by myself, I just — you know, it was overwhelming to witness the kind of reaction I was seeing on faces. I came home and asked my parents about it, and it was probably the first time they started being honest with me about race in the United States.

So I ended up being fairly active. I was president of Fellowship House Youth Group when I was in high school. And I was actually in NAACP headquarters the night Brown v Board was celebrated while I was in high school. So I’ve been acutely aware of racial injustice in the United States since 1947, and not easily always thinking it’s about to end. No longer naive but certainly growing up naively so.

When fair employment practices was instituted in the United States government, I thought, finally. And it’s striking, my bosses at General Electric in 1958 to 1960, my immediate boss was African-American and my boss’s boss was African-American. But there were only four or five African-American engineers in all of GE Evendale at the time — all at GE even then at the time. So, no, I’ve been very aware of integration.

My high school being an exam school did not have anything like a representative number of African Americans. But it changed the lives of roughly 10 or 15, 20 African Americans out of a class of — a graduated class of 300 every year — because we had a 99.9% college rate. And a couple of those people remain lifelong friends, people — I was an athlete, so of course I was around African Americans because I was a basketball player, and around African Americans all the time athletically. So, yeah, for what it is worth, Yale was more segregated when I entered than my high school was.

Zierler:

That’s ironic in a way.

Smith:

Well, it was — I’ll tell a quick story about that. It probably shouldn’t be public. [laugh] My high school principal was Harold Howe. He ended up being Commissioner of Education in the United States where he was called Mr. Integration. His brother was Director of Admissions at Yale. So I had a guaranteed entrance to Yale from the time I was about 15 as Harold Howe simply said, “You’re going to Yale.” [laugh]

Zierler:

[laugh]

Smith:

At one point, I wanted to quit school and go to University of Chicago when I was 16, and he actually interceded with my parents, telling them I could go to Yale. So when I was at Yale, and a group of us — Rich Portes is one of them; he became an economist in England — asked for an interview with Arthur Howe, the director of admissions, because we wanted to discuss how few African Americans — in those days Negroes — there were on the Yale undergraduate campus. And we were sitting in his lounge.

I don’t know if you can quite picture it. You may never have been in that building. And we asked a question, and his assistant said, “Well, let me describe how we go through admitting people. We start on the West Coast to avoid all the East Coast riffraff.”

Zierler:

[laugh]

Smith:

And Rich Portes, sitting next to me, said, “You mean Jews,” and got up and walked out.

Zierler:

Wow.

Smith:

A very memorable moment [laugh] as I say. I walked — I finally caught on, and walked out myself. [laugh] But, you know, this is 1950…either fall of ’57 or spring of ’58. So, yeah, Yale was — Yale in my time was roughly one-third prep school, and people who could care less about academics. It changed enormously as the fraction of high school students increased. And we were in the be…we were in the vanguard of that.

Zierler:

Now, in high school, were you strongest in math and science, or were you strong across the board, would you say?

Smith:

I had very, very high grades across the board. I had a funny — let me explain something about that because it’s a phenomenon. I’m not unique. But as a kid, I was eidetic. I could be shown a page, and be able to read it back to you — close it and read it back to you. And that made me appear to be a lot smarter [laugh] than I actually was because I could do so well on tests, etc., because I effectively had the book in front of me most of the time.

Like most people who are eidetic when they’re young, they lose it in their teens as they go through puberty, I still have a very strong visual memory, but I can’t look at a page and read it back to you anymore. But that allowed me to start reading before I entered school because my mother would read [laugh] to me, and it wasn’t that hard to see what was going on. That’s why I learned to type as a 4-year-old because I was already trying to make up stories, etc. So, no, my academic career was one where I, you know — school came very, very easy to me. It was only when I started trying to do original things in math that I realized that I wasn’t especially gifted.

Zierler:

And when you got to Yale, what was your plan? What did you want to study, focus on?

Smith:

Well, I actually [laugh] wanted to do drama. And what was so attractive to me at Yale was Robert Penn Warren was in the Drama School, and I hadn’t appreciated it when I got — till I got there that the Drama School was separate. But I discovered philosophy as a freshman in Directed Studies. Directed Studies in those years were two years of five courses each required — actually four were required. It changed as more and more people with AP background came in.

And I had the fortune in Directed Studies of having teachers whose response to me because I was — (a) I was interested in things, and that was the exception among Yale undergraduates [laugh] and I had a very strong background. Several different people at Yale sort of tucked me under their wing, and gave me a lot of education beyond my classroom education. I never become an Old Blue, I’ve never gone to a reunion, but I’ve had a great education at Yale.

Zierler:

And how did you go about picking a major?

Smith:

That’s a good question. The major was called philosophy and mathematics. It was a joint major focused very heavily on foundations of mathematics, Gödel or computation theory, all those things, things I still teach because I’m the most qualified at Tufts to teach it. But I quit doing any research in the area in roughly 1980. But it was what I was most interested in at the time was foundations of mathematics and logic.

I was already — remember I could already program computers. I learned to program computers my last year in high school in assembly language because General Electric desperately needed people, and they hired me part-time, and they basically taught me. I thought I had taught myself how to program from a book. I was wrong. [laugh]

Zierler:

[laugh] And, George, I’m curious, when you were taking these science classes, were you thinking that you were going to pursue a career in science, or were you even then interested in the humanities perspective of science?

Smith:

It’s a difficult question. I was interested in a lot of different things. I took off from Yale between 1958 and 1960 to work at General Electric. And those two years ended up changing my life more than anything. Well, I’ll just say what it was.

The last — all but the last few weeks of that — excuse me, first few weeks of that, I was part of a team selected — handpicked team of 50 engineers picked to design an engine for 1985 in 1959. Air Force sponsored it. It ended up becoming a full-time program year after year called ATEGG. But the point was not to create a flying engine. The point was to identify all the impediments to achieving goals that at the time were considered nearly ridiculous.

And I got an on-the-job training as an engineer [laugh] doing that, number one, like most people wouldn’t believe. I was brought in because I knew a huge amount about the computer programs that were being used to design, and they were new, OK. Up to then, engineering — jet engine design had been done with slide rules. So we suddenly had these new computer programs that most engineers were learning to use, and knew very little what was in them.

We were pressing the state-of-the-art. So one of my jobs assigned very early on was to identify safety margins built into analytical techniques, and how much they could be relaxed, so that we didn’t have huge margins of safety blocking us from making advances. What I learned in those two years [laugh] is how little evidence there was for almost everything being done in design practice in engineering because —

Zierler:

And why do you think that was? What explains that?

Smith:

The safety margins simply hide from you how close you are to having your assumptions become problematic. And assumptions remain almost always for calculational ease. Even when you have a computer, the principal question is going to be — in those days, those were vacuum tube computers — how long is this going to run? So, you know, if you look at any engineering textbook, almost to today, you will see all sorts of simplifications of physics made in order to accommodate calculation, and then you put very substantial safety margins on them.

So the net effect of that was to teach me something about evidence, at least in engineering, that astounded me. And I remained part-time the next two years with that project because 50 of us were really tied to it very closely. We actually ran an engine. But it was my first encounter with actual evidence.

And let me make a remark about this. I say this to my students all the time. When you study a science in high school, undergraduate, and at least opening years of graduate school, you learn next to nothing about the evidence supporting it. Much of what you learn is actually false.

Zierler:

[laugh]

Smith:

If portraying things like — I’ll give you an example, the Cavendish experiment of 1798 was a test of Newton’s gravity theory. Well, Cavendish didn’t vary either the masses or the distances between them, which is not a way you test [laugh] at all. And, you know, this is what you learn. There’s a set of myths about evidence that are taught in textbooks.

And I started learning that because, you know, I was teaching myself from engineering textbooks, and at the same time learning that their claims about why to do something were ill-founded. They were simply based on past practice. Of course, the same thing’s true in medicine, though I don’t know nearly as much about that as about engineering evidence. And keep in mind, I ended up being a failure analyst for 40 years.

Zierler:

[laugh]

Smith:

You see why.

Zierler:

[laugh]

Smith:

No, I’m serious, you can see why. And I knew what the limitations were on the empirical basis for engineering practices, and I treated failures as a way of identifying boundaries of ignorance that had been crossed, and what to do about them.

Zierler:

George, were there particular intellectual influences that encouraged you along this line of inquiry about failure and experimentation and evidence?

Smith:

Yeah, my mentors at General Electric, who were extraordinary people. I said two of them happened to be African American: John Blanton , who’s one of the most original figures in the history of jet engines. And then I actually have a jointly authored paper on the advent of fan engines. I didn’t participate in that but my — two people I worked with, two African Americans [laugh] I worked with, one my boss, John Blanton , were at the heart of the first fan engine.

And I was invited by Peter Galison to give a talk on something about jet engines. So I chose this because I can feature two African Americans, and the third man, Dick Novak who was my — another one of my mentors. They wouldn’t let me say they were African-American in the article. But they let me print their pictures [laugh] which took a huge amount off the need to say anything.

But, no, I don’t know what your training is, and I don’t know even most historians — many historians of technology struggle with this. But engineering practice is something that even from the Middle Ages when it was a craft on, you incrementally try new things, and if they work, you keep them. They become entrenched, and then you push them a little further. And the amount of science you sometimes have behind it doesn’t exist.

There was no science behind bridges — they didn’t even have the notion of stress — or a building. So engineering practice remains a lot like that because it outflanks — and particularly in fluid mechanics which engines are all about — it outflanks the existing science. And that taught me a lot.

You know, my whole — when I did start getting really interested in foundations of physics, I approached it fully recognizing that practice in physics is probably a lot like practice in engineering. And whatever evidence there is supporting it, the people doing the practice generally don’t know [laugh] because it’s buried in the past. That’s why I started looking at evidence in physics from a historical standpoint because I thought I couldn’t get it out of textbooks. Is this helping? [laugh]

Zierler:

[laugh] Absolutely.

Smith:

OK.

Zierler:

What was your major? What degree did you get your — what was your major at Yale?

Smith:

A BA. Technically I was a Scholar of the House the last year, but it’s a BA.

Zierler:

In what program?

Smith:

In philosophy and mathematics, the combined program.

Zierler:

And this was a combined program officially, or you kind of put it together yourself?

Smith:

No, it was actually a major at the time. Fred Fitch, whom you won’t — a name you won’t know because you’re too young, is one of the major figures in the teaching of logic. He was at Yale his whole career. He created the program, and it was centered around Gödel’s theorem, the laws of computation theory, etc.

Zierler:

What did you want to do after you graduated?

Smith:

Well, I didn’t know what I wanted to do. And what I chose to do was to take a job at Pratt & Whitney where one of my mentors from GE told them they should hire me because I knew what was in GE programs [laugh] which is why Pratt Whitney hired me. And there I got to be head of a group called the math — that became known as the math analysis group.

They had been having professional computer programmers do their programs for designing jet engines, and the programmers didn’t understand jet engines. So I was hired to create a group in which I would take engineers, and teach them, you know, oversee their learning how to program so that Pratt & Whitney’s programs would be developed by people who understood jet engines. And I was there for two years doing that in 1962 to 1964.

Zierler:

Did you ever consider going straight to graduate school from Yale?

Smith:

No, I did not apply to go to graduate school straight from Yale because I really wasn’t sure what I wanted to do, what field I wanted to be in.

Zierler:

And so did you look at entering industry as an opportunity to narrow your interest, gain a little more focus?

Smith:

At the time, I wasn’t particularly thinking that way. I mean, ’62 to ’64 is an — I was sitting at my desk [laugh] in November 19…22nd, 1963 when there was an announcement over the PA system that Kennedy had been shot. [laugh] I got married in 1962. That’s a crucial fact to not going on to graduate school because I had just gotten married.

If I had gone on to graduate school, it would’ve been Yale. And it’s probably very fortunate I didn’t go on to graduate school at Yale. But we lived in New Haven, and I would — you know, I worked at Pratt & Whitney, thinking I would go back to graduate school. But I didn’t even apply till 1964.

Zierler:

How large did the Cold War loom during your Pratt & Whitney years?

Smith:

Almost none in those years, but very heavily in my subsequent years — in subsequent years of the ’60s. I mean, simply put, my career in jet engines was always military jet engines because I was always working on the cutting edge, and you don’t put cutting edge jet engines into commercial aircraft. [laugh]

You instead take military engines, and back off on them to make them have a longer life between overhaul for commercial purposes. So I had almost nothing to do with any commercial jet engines till much later. It was all military.

But in the early ’60s, Vietnam wasn’t really looming. I stayed out of the draft because Pratt & Whitney kept me out of the draft. I was listed as a vital emp…you know, vital to the United States employ. I was actually — I actually went through the physical to be drafted, and then Pratt & Whitney interceded. That was in the spring of 1963.

But the Vietnam War did not become — it didn’t become the quagmire until after Kennedy died. And I was a great admirer of Kennedy. I — you know, we — 1960 was a wonderful event from my point of view. It’s almost comparable to Obama being elected. Here was a young person, all new outlook, etc., and, you know, what else can I say?

But, yeah, at the time, throughout this time, I was [laugh] — I am still fundamentally just a problem-solver. I get excited in solving problems. And jet engine design, which was entering a whole new era with faster computers, was a very exciting thing to be at the forefront of. So I was not unhappy in my work.

At Pratt & Whitney, I had less contact with evidence than I had had at GE because I wasn’t working on engines themselves. I was working on design methods. But I would talk to people about what we were doing in computer programs, and what the basis of it was.

And so I did see a fair amount of Pratt & Whitney test data. Pratt & Whitney was very test-oriented; not analytically oriented. GE was just the opposite. So the whole idea of my being at Pratt & Whitney was to install — I wasn’t important enough to be installing it — but to help to install computer-based design methods.

Zierler:

How did you know it was time to go back to school?

Smith:

Yeah, I felt so, so I applied, and entered Harvard in ’64. Burt Dreben, who was a logician and in the field of foundations of mathematics, had invited me and one other student my junior year at Yale to come up once a week to Harvard to attend his seminar on someone called — a dissertation of Jacques Herbrand.

It was an interesting seminar because other people in it included Noam Chomsky, Jean van Heijenoort, David Lewis. They were almost all invited. I think there was one registered student, and everybody else was invited. So I saw myself as wanting to work with Dreben, and continuing the kind of work in philosophy and mathematics that I had been doing at Yale. And so I got into Harvard probably because of the tie to Dreben.

I had actually known Chomsky — I met Chomsky in 1958 because he spoke at Yale at a time I was taking a linguistics course. My sophomore year, I actually took eight courses my spring semester because Directed Studies wasn’t giving me much leeway. [laugh] So I started taking more courses, and got to know Noam at that time.

And, I mean, simply put, it’s a strange thing to say. I read his mimeographed Logical Structure of Linguistic Theory in the Linguistics reading room before I met him. He was taken aback that here was a kid who had read it and understood some of it. And we remain reasonably comfortable with one another.

But I bring this up because he was the first practicing scientist where I learned how a really good scientist thinks. And a lot of my views about how science works come from watching Noam. I’ll make a point to that. I have a slogan. Others have picked it up. It’s even been a subtitle to somebody else’s book, but crediting me. “Science is an endeavor to turn data into evidence.”

Zierler:

[laugh]

Smith:

I appear to be the first person to have printed that in 1983. But Noam and I were unable to figure out who said it first. [laugh]

Zierler:

[laugh]

Smith:

But the — for me, I learned it because there’s no field of research in which data are more plentiful and more at hand than in linguistics, and in which evidence has been harder to come by. And the lesson I learned is you’ve got to have theory to turn data into evidence. And that’s been the essence of my whole career as a philosopher of science is to look at the process of how theory turns data into evidence without becoming viciously circular.

Chomsky taught me that, and Chomsky was in this course in 1961 [laugh] sitting in in the spring of ’61 with Dreben. And so I entered Harvard. I quit at the end of the one year. I was very unhappy with the whole tone of the Philosophy Department at Harvard. And Burt Dreben is no longer alive, and I probably came to appreciate history more from him than any other human being.

But Burt wanted his protégés to be very much like him, and I mean through and through, the way you talk, you dress. And that made me very uncomfortable. And so the same mentor who brought me to General Electric had by then moved to a consulting firm in Cambridge. He approached me in the spring of 1965, asking if I might give them some help because they had a contract, and I knew a lot more about how to carry out that work than anybody they had. I enjoyed doing it, and I then became full-time with them, and I left that organization in 2013. I retired from engineering in 2013. [laugh]

Zierler:

[laugh] George, how did you go about developing your dissertation topic?

Smith:

Well, actually, at Yale, if my disserta…excuse me, at MIT, my dissertation topic was not on science at all. It was on quantified modal logic . It arose because Dick Cartwright, my mentor and in philosophy at MIT the person I was closest to and I read Saul Kripke’s Naming and Necessity together, and came up with a series of proposals about what needed to be done in quantified modal logic . And he said, “Turn that into your dissertation, and get out of here, because if you try to write a dissertation in philosophy of science, you’ll be here forever.”

Zierler:

[laugh] Good advice.

Smith:

And he was quite right about that. It was a very wise piece of advice. So I wrote that, wrote one paper, and never followed it up, other than occasionally teaching it, because, you know, I started doing philosophy of science full-time. Just as an aside on this, you brought up the Vietnam War, and this is fairly important.

One of the things I had done as an undergraduate at Yale [laugh] is sit in on a lot of political science courses, particularly Karl Deutsch’s classes, Westmann’s[?] classes. I had — during the ’50s, I developed a very strong interest in whether political science can be a science, can be empirically based. When the Vietnam War got nasty, and of course, at that time, I was helping — I was actually consulting on what was called the TFX. It became the F-111. It became a weapon for Vietnam. [laugh]

And I was even to the point of doing flight testing on it in California where I was on the ground, of course, but they were — I was monitoring tests. [laugh] So I got more and more uncomfortable with Vietnam. And meanwhile, Kenneth Arrow got the Nobel Prize for, among other things, the Arrow theorem, Arrow paradox, which says that a democracy cannot vote in an optimal allocation of public good resources. And that got me back interested in whether political science can be a science.

So that’s what led me into getting interested in the foundations of physics. The sequence goes as follows. When I was a graduate student in philosophy at MIT, I taught courses in the Political Science Department as a lecturer on computer models in political science. And I almost had chosen to go into political science at MIT rather than philosophy, but I felt more comfortable with philosophy.

When I first got to Tufts, I actually taught a course in philosophy of social science because my primary concern was social science, and idealizations in social science, because, as you probably realize, economics has this idealization of the rational actor. And that was what Arrow was dealing with in political science. But very quickly by one or two years into my teaching at Tufts, my interest changed from whether political science could be a science to trying to understand [laugh] the epistemic foundation of a science, physics. Because I thought I had to understand physics as a science [laugh] before I could remotely tackle the question, can political science be a science?

And I never got back to political science [laugh] as a science because once I started getting into physics, and realizing how complicated evidence actually is in physics, I got very excited. I still could probably teach a political science course — empirical political science course because I follow the literature to some extent. But I’m not very sanguine about it being a science.

Zierler:

Who was on your committee?

Smith:

At Yale or you mean at MIT?

Zierler:

For your dissertation.

Smith:

Yeah, George Boolos and Dick Cartwright. There was only two people at MIT.

Zierler:

Only two? That’s small.

Smith:

Yeah, no, the MIT Political Science Department — excuse me, the MIT Philosophy department, Karl Deutsche created the MIT Political Science department, which was right next door to the Economics Department, which was a world-class economics department, as you probably realize. Philosophy Department sort of came into existence out of humanities, and people were brought in, like Dick Cartwright, to create the program. It’s a thriving program. It’s been there for a long while.

It got amalgamated with Linguistics in 1978 or ’79 when MIT ruled that every department had to have a certain — every department with graduate students had to have a fraction of their salaries come from soft money. And it was very hard for philosophers to do that, so Noam stepped in and combined the two departments so philosophy could continue. It’s been Philosophy and Linguistics every since. But the two have not a whole lot to do with one another.

Zierler:

And after you defended, what did you want to do next? What opportunities were available to you?

Smith:

Well, I wanted to teach. I wanted to stay in Boston, so I only applied to two teaching jobs, one in the Political Science department at MIT, and the other in Philosophy at Tufts. I wanted to stay at Boston because by then, I was a $200-an-hour consultant. We were about to have a child. It turned out to be two. And I didn’t feel I could deprive my family [laugh] —

Zierler:

[laugh]

Smith:

— of money at that stage, so I wanted to continue consulting. But actually I loved — by then, I was doing almost exclusively — or not quite exclusively — failure work. I found it enormously exciting. I found being an expert witness enormously exciting because it made me see evidence from a legal standpoint. Something I’ve actually taught courses, undergrad courses in comparing the legal and scientific evidence.

So the net effect was when Tufts offered me a job, that was perfect because it was, you know, 15 minutes to my consulting job. And in fact before the year 2000, I made more money consulting than I did as a faculty member of Tufts every year, one day a week. [laugh]

Zierler:

Were there any ethical or legal hurdles that you needed to overcome in order to remain dual-hatted as a consultant and as a young professor?

Smith:

I was a very successful teacher, and managed to do a modicum of publication; enough publication to keep myself — to get tenure. But nobody ever questioned it at Tufts. I wasn’t dishonest. They would actually have me lecture engineering courses even on failures and about jet engines as a visiting lecturer.

But I think it was almost part of the deal — I certainly thought of it that way — that they would allow me to continue to work in my engineering career so long as I met — you know, I was a responsible figure in the community, a responsible faculty member. And nobody — well, I’ll say two things about that. Nobody ever asked me, questioned me about the engineering. It was always above board, number one. Number two, I never asked for a raise. [laugh]

Zierler:

That helps. [laugh]

Smith:

That’s right. So here I was an associate professor, not asking to be a full professor, doing my thing. Until finally, after I was six years as head of the Dibner Institute, they decided [laugh] that maybe they should make me a full professor. [laugh]

Zierler:

And what department did you join at Tufts?

Smith:

The Philosophy.

Zierler:

Philosophy. And what were research goals at that point? How did you want to define your sort of scholarly agenda in terms of the topics and the areas you wanted to focus on?

Smith:

All right, that’s fair. I’ve already told you that I started looking more and more at science because of political science. One other thing I should tell you, I read Kuhn’s Structure when I was at Harvard in ’64. And I had two reactions to the book. Let me back up.

In 2007, Stanford asked me to give a series of lectures covering the last 25 years of my research, and I — you know, [laugh] what? [laugh] How am I supposed to do that? Three one-hour lectures? But in preparing those, I did indeed — and they’re available publicly — I did indeed cover the last 25 years of my research. And I’ll come back now. I’m going to be answering your question indirectly.

But somebody pointed out to me, “You realize what unifies all these lectures? You’re responding to Kuhn.” [laugh] And I had not thought of that. But one thing I recognized and used reading Kuhn’s book is his idea of paradigm struck immediately with me because of engineering. The difference between General Electric and Pratt & Whitney’s approach to designing jet engines was a perfect example of the Kuhnian — two Kuhnian paradigms that were somewhat incommensurable, the approach was so different.

So already my first year I taught philosophy of science, I taught Kuhn; not as something I liked but as something that was challenging what is the claim to epistemic superiority of physics? What is it based on? And that became a preoccupation right from the beginning when I started looking at physics.

The other thing though, the primary focus in conjunction with that, is to look at episodes in science where you go from not being able to turn data into evidence to being spectacularly able to do so. So, for example, Lavoisier in chemistry, what my third lecture at Stanford was actually on seismology and the internal structure of the Earth. Because in a very short period of time, they realized that seismic waves were telling them [laugh] what the internal structure of the Earth was.

So that became the focus. And the focus initially was therefore on the period from 1897 with J. J. Thomson and the electron, through Bohr, and the reception of Bohr through 1915. And that was the period where we went from not being able to get very successful evidence of microphysics to starting to get spectacularly good.

And what I wanted in every case that I studied like this was to ask how did theory manage to leverage across such a huge divide so quickly, and not be circular in the process? What were the cross-checks? How did they work? OK. So that was the focus, and so much of my research focuses on specific historical very short periods of going from somewhat floundering until to being extraordinarily successful. I looked at Newton purely as an example of that in 1987, never thinking I would become a Newton scholar.

Zierler:

[laugh]

Smith:

I did become a Newton scholar. But it was just as part of that because, of course, that’s the granddaddy of all of them. Orbital astronomy had been around for 1,500 years. It had been a fairly advanced science from Ptolemy on. But it had not been able to do much beyond get a representation of the motions. And of course subsequently celestial mechanics down to the 20th century has been inordinately — it’s still continuing — a great evidence success story.

So the paper of mine that’s probably most widely acknowledged is called Closing the Loop, and it’s testing of Newtonian theory. And so it’s a paper on evidence in celestial mechanics, and how it’s much more than just agreement between calculation and observation. And I’ve a book about to appear within six weeks, jointly authored with an undergraduate, on the period from 1900 to 1913, and the measurement of fundamental constants during that period. [unrelated conversation] But Chomsky remained interested in my work, precisely because it was focused on these transitions, and he was trying to effect one. It’s a really interesting study.

Zierler:

George, as prelude to Newton, I’m curious, you know, you’ve described so beautifully, you know, your overall historical inquiries, right, and how, you know, you wanted to get at these large-scale issues. So prior to your focus on Newton, what were some of the — I don’t know what the right word is — case studies or themes or topics that you felt were most productive as vehicles for exploring these issues, prior to your, you know, becoming, you know, so focused on Newton?

Smith:

Well, the one I had concentrated on is the one the book is coming out on. I didn’t concentrate on Brownian motion, and the book’s title is Brownian Motion and Molecular Reality: A Study in Theory-Mediated Measurement. But I start my philosophy of science course with J. J. Thomson’s 1897 paper because it’s so monumental on the evidence, and it is so accessible.

It gets order of magnitude values for m over e for the electron more than a factor of 2 variance, and two ways of doing it, and the data don’t even overlap the two ways. But they are three orders of magnitude less than the m over e for hydrogen — hydrogen ion. And so the principal focus I had throughout this period was, yeah, before I got started studying Newton, was in fact on how we got from Thomson’s cathode ray experiments to the Bohr model, and the reception of the Bohr model.

I didn’t pay much attention to Brownian motion during that time, even though I taught it. But an undergraduate wrote a paper in my course on it, then he wrote a senior essay on it, and that senior essay is now a 450-page book. [laugh] It’ll be appearing in six weeks — in the next six weeks by Oxford University Press. And the focus throughout that period was how does theory-mediated measurement form a constituted form of evidence in its own right? And that’s become an ongoing project now.

I had a meeting this morning with two former students, one in Edinburgh and one in Singapore. We do so every Tuesday morning on a project on precision measurement of the fine structure constant over the course of the last 100 years. But, no, I know, it’s a perfect example of you need theory to do a measurement. How are you not kidding yourself? What’s the cross-check that you’re actually getting something meaningful?

So one of the first papers I published that you would call historical is in the volume, the Dibner volume on the electron. It’s the first paper in there. It was not invited initially. I was not invited to the conference. But Jed Buchwald learned from — Bernard Cohen that I had given a talk at Chicago on the anniversary of J. J. Thomson’s announcement at the Electrical Institute of what he had done with cathode rays.

And so Jed asked me to write an article, and it became the lead article. And I would assume — I don’t check these things — I would assume it’s the most cited article of mine. A few years ago, I had to — I wanted to quickly find a Thomson paper, so I went on Google and discovered my paper [laugh] is the first thing that came up, which of course didn’t help me. But it was that period, and I learned a lot about theory-mediated measurement during that time.

Zierler:

George, what do you have to say about this binary in physics between theory and experimentation in terms of how physicists define themselves? I’ve noticed it’s such a very strong trend. What do you think explains that intellectually over the course of the 20th century, 21st century?

Smith:

Well, you’re the historian, in a sense. I see several factors too in it. It was not typical before 1900. OK. Maxwell did major experiments, including an experiment of crucial to statistical mechanics verifying that viscosity is not a function of density, which he initially thought was enough to prove — he thought it had to be a function of density, and therefore thought it showed that statistical mechanics was a dead end. He announced that in 1860, and then was persuaded — persuaded himself after talking to some people — to verify [laugh] that viscosity is a function of density.

It turned out not to be. So, you know, he was an experimentalist in lots of respects, even though he was also a theoretician. Einstein — excuse me, Newton, needless to say, was an experimentalist. You look at 19th-century figures, and they — there’s the combination of the two. One thing that changes is of course Einstein, and Einstein is a model. I don’t know if you’re aware of that.

And Einstein in his first paper on Brownian motion says at the beginning, “I don’t know if this is Brownian motion or not. I’ve never seen it.” Did he go to the trouble to try to see it? Of course not. OK. So Einstein is somebody who sat at a desk and created theory. Not all the theory worked right away, etc. But he became a model for doing that.

A second oddity is in the ’20s, experimental physics in the German universities took an extreme backseat. There was — you just weren’t going to get ahead being an experimental physicist. And of course Germany was the center of physics at the time. The Americans were going over there.

There were two oddities of that. Sommerfeld was the one person who respected experiment. And second, it allowed the United States with Millikan and Compton to become [laugh] leaders in experimental physics.

But, I mean, you should ask somebody like Paul Forman a question like this. I have — until the pandemic, I had lunch with him once every three weeks — because it’s almost certainly a sociological phenomenon to some extent. The other thing you have to consider though is the level of mathematics that you need to become facile in in both microphysics and general relativity, even special relativity with Minkowski spacetime.

That’s an awful lot of training to become facile. I don’t mean just being able to read it. I mean to work in it and have it second nature. At the same time, experimentation especially in microphysics required more and more training to design experiments because the design of experiments became so remarkably elaborate.

So I think to some extent, it’s simply the maturation of the science, and the increasing tendency, what Tom Kuhn was most preoccupied with the last 10 years of his life, what he called the speciation of science. A division of, in this case, physics into a couple of hundred sub-disciplines [. And I think that in Tom’s argument — it’s an unpublished manuscript, half-finished — I was — I got to know him well in the last year of his life because I was the person he asked to talk with him twice a week about that manuscript.

But he thought it was part of becoming mature to divide it into all these sub-disciplines because the amount you needed to know to pursue continuing research was so — had to be so narrowly focused that very few people could cross areas. I mean, in both his view and my view, Fermi was one of the last to be able to comfortably go across. Bethe, Sam Schweber would argue, less probably the last. But it happened, and it happened probably in large part because experiment in microphysics is so hard to do, and also in large part because of the math required to do theoretical work is so much beyond advanced calculus.

Zierler:

George, your use of the term “microphysics,” I’m curious about that. Are you in the same place as Peter Galison in terms of what microphysics means, or do you have a broader context in how you use that term?

Smith:

I’m not com…I’m not immediately — it doesn’t immediately come to mind how Peter uses it, so I’ll just have to say how I use it. All research into physics that is beyond the capacity of our senses to observe, and that to me starts with atomic theory in chemistry, but even more so with Clausius’s statistical mechanics, and Maxwell-Boltzmann in the 19th century. So I think of microphysics is becoming an area of intense research, starting around the late 1850s with Clausius.

And all through the 19th century, unsuccessful research in statistical mechanics because they had to assume spherical shape for molecules to get anywhere. And when you assume spherical shape for molecules, you don’t get results — I’ll quote James Jeans. You get discordant results. So they didn’t have much success.

One of the — if there’s a single paper that most influenced me, it’s actually Maxwell’s The Dynamical Evidence for the Molecular Constitution of Matter. It’s an 1875 lecture before the Chemistry Institute. It taught me how to read Newton. But the whole idea is we can use macroscopic phenomenon and statistical mechanics to do measurements at the microphysical level. They can be cross-checked by other such measurements. And with it, we can gain experimental access to the microphysical realm.

And they failed to do it. I said why they failed to do it is the — the first long chapter of the book that’s about to come out — why they didn’t succeed in the 19th century. The assumption of spherical molecules — they had to make an assumption about shape. And with it, to give you an example, they would derive Avogadro’s number for six different gases from viscosity, density, etc., and they’d get substantially different Avogadro’s numbers. [laugh] So they knew they weren’t doing it.

And, you know, this was recognized by the physics community. And so, to me, microphysical research is simply gaining access to a realm we cannot observe. The third of my lectures — and the lectures are called Turning Data into Evidence: The Role of Theory in Experimental — in Scientific Research. Those were the Stanford lectures. The third one was on seismology and the deep structure of the Earth. And it should be obvious the two situations are totally analogous.

We will never observe the liquid outer core of the Earth. The temperature and pressure are way beyond any instrument we could possibly put there. Yet we have gained incredible experimental access to the internal structure of the Earth through theory-mediated measurement. That’s the kind of example that Maxwell was looking for that didn’t work, and that’s — you know, that’s what I’ve been focused on. Maxwell’s paper, Maxwell’s lecture, 1875 lecture made me realize that’s what was going on in the Principia. That’s what was Newton doing — Newton was doing. Now Maxwell knew that. He references the Principia.

Zierler:

George, I’d like to ask you a more contemporary question on evidence. I’m sure you’ve been an interested observer — I don’t know if direct or on the sidelines — within certain controversies in physics relating to the issue of testability, particularly with concepts of the multiverse or with string theory, and questions about, you know, can things really be considered science if we have no way of testing for them? I’m curious in terms of your long-term interest in evidence what your reactions have been to these sort of intramural debates within the physics community.

Smith:

Well, my initial statement, and I’m going to make it as strong as possible, as a philosopher who doesn’t actually do physics and hasn’t done it for years, I have no business, number one, telling physicists [laugh] what to do; number two, trying to do it for them. [laugh] I’m not a philosopher of physics trying to come up with interpretations of quantum mechanics because I think that’s an empirical problem. What I recognize — and I’ve more recently formed a personal relationship over the last seven years now with Steve Weinberg, so I’m to some extent just getting back to you from conversations with him — at the present moment, the areas you’re talking about are struggling because they have no experimental or empirical guide on how to go beyond the standard model.

And the reason they don’t is because they need to get to energy levels that they have never gotten to, other than the Big Bang. And it turned out the Big Bang so far has not proved as informative as people following Guth had hoped. So my reaction is to ask myself has there ever been a situation like this before where people are just trying to construct physics through beautiful mathematics? And, yeah, the answer is quantum electrodynamics in the ’30s [laugh], the Dirac Theory, and go back and look at it. And look at Sam Schweber’s book, QED and the Men Who Made It, and the years before Shelter Island, you will see exactly the same thing going on.

They did not have an experimental basis to figure out how to incorporate special relativity fully into quantum mechanics. They were trying to do so largely guided by mathematics and the beauty of mathematics where Dirac was especially sensitive to this. But in fact the theory never worked. [laugh] It worked for some things very well, but it actually never worked. And they even had some experimental evidence it was not working.

In this case, as far as I can see, like, you know, Sam Schweber had me looking — he wrote a long introduction to the reissue from Shelter Island II. Shelter Island II — which was what, 1983 — is a meeting on which things like string theory, etc., were at the forefront because they were trying to get beyond the standard model, and they had no experimental basis for doing so, so they turned to the mathematicians. And my reaction was when you’re depending on mathematics and beautiful mathematics, you don’t have much basis for saying it’s empirically true. And when you can’t get any connection, even some form of measurement, you’re not very well off. [laugh]

You know, Dirac kept saying through the ’30s, “We need a more fundamental theory than the one I have. The one I have is not deep enough.” And that’s a situation we’re in now. And, you know, Weinberg says, I’m just parroting back.

This is the kind of thing I stay out of though because, number one, I feel I have zero to contribute. Number two, I won’t really be in a position to understand the controversy. Number three, if I can contribute anything to the help of physicists it’s to show them how evidence works in the long run, and in particular how a theory can continue to be tested decade after decade without it explicitly being said to be tested, because it’s being presupposed in ongoing research and is, as it were, en passant being tested. You know, I feel good that when physicists see my work, even people like Steve and Ken Wilson, they feel it’s valuable to them simply —

Zierler:

In what ways do you think that they feel like it’s valuable to them?

Smith:

Well, in Ken’s case, he openly would say that the experimental grounding in physics was so much deeper than he had realized. He used to say, “Any physicist knows nothing about evidence before the time they became a graduate student or postdoc. After that, they know everything about evidence.”

Zierler:

[laugh]

Smith:

But they simply take for granted that the foundations are there. And they’re not always there. But when they are, they can be much more impressive than the agreement between observation and calculation. And that’s the point of the Closing the Loop paper, how much more impressive it could be. So, yeah, I would like to believe that some physicists looking at my work take comfort in it [laugh] at least.

But, frankly, my work — philosophers of science don’t think of my work as philosophy. They think of it as history. Historians think I’m a philosopher. [laugh] And of course I’m not trained in history, and you are, and you know the difference. I’ve been — in the last seven years, I’ve been doing a great deal of manuscript work. I’m starting to believe I’m trained in history now. [laugh]

Zierler:

[laugh] So, George, I’d like to ask now about — let’s have a more detailed conversation about Newton. When — how did that actually start for you? When did you get involved on a sustained basis?

Smith:

OK, that’s an interesting question. Tom Kuhn and I knew one another in the early ’80s when he moved to MIT, and he was doing a course, his course, start with Aristotle, and go through Newton. And I showed up, sitting in on the course, and he asked, “What are you doing?” And I said, “I’ve started to get into Newton.” He said, “Why don’t you teach the last classes on Newton?” So it’s 1983, but I was totally dabbling. I had not read the Principia cover to cover. I had only a limited amount of the background I needed to read it historically in context.

So in the tercentenary year, 1987 — ’86, ’87 — I decided to teach a full-year course, the first semester of which would start with Ptolemy, and look at the development of evidence in orbital astronomy up to 1684 when Newton starts the Principia. And then the second semester read the Principia cover to cover, which I had not done. And I knew I would never do it [laugh] except by teaching the course.

I taught the course, and came to realize — this is a statement I make all the time — nobody I’ve encountered thought more carefully and closely about how to develop high-quality evidence in physics than Newton did. [laugh] That’s why I’m doing the manuscript work now because I’m bringing out a bunch of stuff that’s never been published to show that during the development of the Principia. So I taught it, and was very pleased, but thought I would never teach it again.

Then I was invited to give a talk about Newton, and that led to an invitation to give another talk. But what actually happened that changed everything was Bernard Cohen had a new translation. Anne Whitman had died 1984. She in fact was a patient of my wife’s. And Bernard had put their translation to one side after she died.

And in the year I — the first year I taught the two-semester Newton course, which I guess is what I’m best known for, I had six outside speakers, and he was one of them. And I asked him what’s going on with the translation. And he simply said, “I can’t bring myself to work on it since Anne Whitman died.” That was three years afterwards. And my wife sitting between the two of us said, “Anne Whitman?” And all of a sudden, I got a friendship with Bernard Cohen [laugh] because I was once removed.

So in 1990, he decided he really wanted to finish that translation, and he asked me to teach the ’87 — ’86, ’87 course again using the translation side-by-side with the existing translation. And by then I had read the Maxwell lecture, and I’d come to see Newton much richer. And so ever since then, I’ve taught the course every other year. It changes every other year. Every time I teach it, it gets richer because there’s more to be learned.

But it just turned out that doing — looking in real detail at the history of evidence on gravitation theory post-Newton, which by the way includes the deep structure of the Earth — looking at that in detail was so enriching and seemed so good for students that I simply continued to do it. The two times I taught at Stanford, I was invited by faculty, and I had more faculty in that course than I had students. So I did get six PhD students at Stanford [laugh] out of that course.

Zierler:

[laugh]

Smith:

Which is of course unusual because I wasn’t a Stanford faculty member but I was on their committees because it came out of the course. So, no, it’s just proved to be a vehicle. Now what did happen, I didn’t look much at manuscripts after Bernard died. He wanted me to do some work on manuscripts. But I wasn’t that comfortable doing them until finally just an offhand question from Rob DiSalle about a manuscript history made me start seeing how rich the manuscripts are.

So since — essentially since 2012, I’ve been doing primarily manuscript work on Newton, and this book on microphysics from 1905 to Bohr, in effect, and measurement of fundamental constants. And I now have this project going on on the 20th century history of measurement, precision measurement of fundamental constants. That was something I had started working on with Ken Wilson before he died. We were going to do a project together on the evidence for the standard model coming out of measurement of fundamental constants.

Zierler:

George, are you surprised in the beginning that the course struck the chord that it did?

Smith:

Well, I had been thinking hard about how evidence works for 10 years. And I suddenly found somebody in front of me reading, somebody who had not only seen everything I had seen [laugh] but was way ahead of me and was self-consciously asking himself how to get the highest quality evidence in physics. And he says it in various places. There’s a wonderful statement that I’m paraphrasing. If you want to use that quote, I can give it to you. This is in the early 1670s before we got anywhere near the Principia.

He’s talking about optics, and he’s saying, “If the geometricians would start paying attention to natural philosophy, and the natural philosophers would start paying attention to geometry, maybe we would finally be able to get beyond all these wild conjectures.” And now the actual sentence is, “Achieve a science of nature supported by the greatest evidence.” And that’s what the Principia is trying to do in his own mind.

He saw an opportunity to do what he had not managed to do with optics to the extent that he had hoped. And all these years of thought about how to get high quality evidence and how to achieve the greatest evidence combining mathematics with natural philosophy, so to speak, came together. And, you know, there are three editions . They change from one edition to the next. That’s instructive.

The manuscripts leading up to the first addition are instructive. I have copies of his — I have scanned copies of his personal copies of the Principia. They’re very heavily annotated. Then where he’s making revisions or intending revisions, some of which he ends up not making, he’s constantly thinking about how to strengthen the evidence.

And so he’s proved more instructive to me than anybody, other for my personal thing, other than my own experiences as a failure analyst where the experience you get as a failure analyst is never — you always subject your evidence to the most intense criticism because if you’re wrong, something — the same failure’s going to happen again. OK. So I got taught to really scrutinize evidence. And, you know, just ask yourself what’s the weakest element in this evidence?

And you can see in the Newton manuscripts him saying — doing that very thing. What’s the weakest element? Not every physicist does that [laugh] to the same extent. And it struck me when I saw Maxwell doing it in that lecture. And, I mean, you know, that’s — I think I’ve answered your question.

So Newton is — the other thing of course is I think I’m contributing a lot to my students, many of whom are actually faculty members from around Boston. I have always had at least as many auditors as students. I think there’s something very, very valuable about seeing what the transition was from before the Principia to 19th century celestial mechanics, and what enabled it to happen, how it happened, etc. And it was not a matter of luck. It was a matter of great, careful thinking by an extraordinary mind, you know, that’s —

Zierler:

How is it that you can continue to mine Newton, and still find new things, and make the course richer year after year? What does that say both about Newton and the nature of historical inquiry in science?

Smith:

Let me do the latter first. On the whole, history of science, which I think of as a discipline coming out of Sarton, and that Bernard Cohen was at the forefront of the creation of it as a discipline, has focused very heavily on history of ideas, conceptual history. How do new ideas emerge? There is a very little history of evidence in history of science. An exception is Curtis Wilson who of course had a huge effect on me.

So one element here is people who look at Newton don’t look at it from the point of view of what has the history of evidence in orbital mechanics been. And the standard view is, well, calculation kept succeeding. In fact, from the time Newton published the first edition of the Principia until 1991, there is one brief 25-year period — essentially 25; it’s depending on how you count it, it could be as much as 30 — when there was no known discrepancy between calculation and observation in celestial mechanics. In other words, the evidence was coming not from agreement but from disagreement.

Zierler:

Oh, wow, that’s interesting.

Smith:

Yeah, but it’s in Newton. He sees that. That’s why he attacks the problem of the lunar orbit . And if you want an example of how you could keep learning, there’s a proposition in Book 1, Proposition 35. It has two cases. Almost nobody has ever written on it. I’m now writing on it. I was invited to give a talk in the last — two weeks ago in Berlin at Max Planck on approximation in Newton. It of course got canceled till next year.

But I went back and looked at Proposition 65 , which Case 2 I had featured for some time. Case 2 does the following. It takes our solar system or any other orbital system, and raises the question of the possibility of an external force, gravity-like force acting almost in parallel and almost equally on all bodies in the system, and therefore being not readily detectable. Could that undermine conclusions from the motions of the bodies within the system?

And Case 2 gives a classic — earliest place I know of — piece of asymptotic reasoning that it doesn’t. By asymptotic reasoning, Newton says the following: “Give me any number. If the force — I can have the source of the external force be far enough away [laugh] that all the perturbations will be less than that number.” OK. That’s asymptotic reasoning of exactly the form Einstein did with Newton. I had never looked at Case 1 carefully.

The worry in Case 1 is Newton is proceeding from representations of orbits that are referenced to the sun. But his — according to his own theory, the true motions have to be referenced to the center of gravity of the system. He does the same asymptotic limit there, saying as the masses of the other orbiting bodies get lower, the center of gravity approaches the center of the central body of the sun. He’s worried about justifying an approxim…drawing a conclusion of a real force from an approximate representation of the motions.

I’ve known for years about Case 2. I had never noticed what he was doing in Case 1. Even though I knew it was asymptotic , I said, “Why’s he worried about this?” OK. So, yes, you learn new things. I have a weekly meeting with Rob Di Salle working on Newton, and he was surprised at that. He had never noticed it. Bernard in his guide doesn’t saying anything about Proposition 65 at all.

Zierler:

You have such an interesting relationship with Newton. It seems like every time you discover something new, Newton was already there to anticipate what you were about to find.

Smith:

Well, I found of course writing about approximations, the fact that he would do in a technical modern sense of asymptotic limit justification or something that’s not true but that would hold in the asymptotic [?] limit, you know, something Einstein made famous with Newton, and then Bohr made famous [laugh] with the correspondence principle. Here it was, sitting there. But I’d known that for a long time. I just hadn’t appreciated that he was worried about referring the motions to the sun rather than the true motions having to be referred to the center of gravity.

Now, let me back up a moment. I became a recognized Newton scholar for a reason, and it’s worth telling you now. I of course, have a background in fluid mechanics. I taught the Principia cover to cover. Truesdell in a famous lecture in 1966, the 300th anniversary of Newton’s Miraculous Year, Annus Mirabilis [?] [??], Truesdell had said, “Obviously Newton scholars, their copy of the Principia is defective because Book 2’s not included in it.” Because there had been no commentary on Book 2 since the middle of the 19th century.

I saw immediately what was going on in Book 2. You know, I had a fluid mechanics background. So I became a recognized Newton scholar among the existing ones almost overnight in 1995, ’96, by giving a paper on what’s going on [laugh] in Book 2, and then being invited to give a whole lot of other papers on Book 2. And of course what’s going on in Book 2 is totally of a piece with what’s going in Book 1. He’s trying to do theory-mediated measurements of resistance forces, and he’s having great trouble — which we still can’t do.

Zierler:

Why not?

Smith:

Because of turbulence, they’re not — we can do them, but we can’t really — we’re doing them crudely. We’re not really able to link it to anything in theory in effect. I’ll say this in a straightforward way. We continue to test aircraft scale model in wind tunnels because we cannot calculationally predict how they’re going to act full-scale, because the flow is too complicated. Things are improving monumentally.

There’s a 1985 paper reviewing computational fluid dynamics in the design of aircraft in the Journal of Aircraft. It reviews six aircraft, three of which when made full-scale functioned fine; three of which were disasters and had to be abandoned. And the final sentence, and I think word-for-word, “All we’re asking from computational fluid dynamics is to tell us which three not to build. We don’t care why.” [laugh]

Zierler:

[laugh]

Smith:

But that’s the state of fluid mechanics as a field of physics. OK. Computational fluid dynamics has computers become more and more powerful is getting better, but it is not capturing turbulence yet. That’s a Nobel Prize waiting to happen. In fact, if you go back and look at the statement made by the person in Sweden in giving Ken Wilson his Nobel Prize, the statement is because of he did phase transitions, now there remains only one unsolved problem in classical physics for which a Nobel Prize will someday be awarded: turbulence. He worked on it for a while, by the way, and gave up. [laugh]

Zierler:

What do you think the blind spot is with AI with regard to turbulence?

Smith:

Well, as far as we understand it, I’m now talking like a fluid mechanical engineer, what happens in turbulence is the constant transfer of energy from large eddies to small eddies to still smaller e3ddies going back and forth. Anything you do analytically, you cut the scale off at some point, and try to represent everything below it by a lumped parameter. And lumped parameters can then be calibrated off of data for some purposes.

But when you extrapolate to an entirely different phenomenon, turbulence phenomenon, they don’t work. So, for example, you can get very good coefficients for turbulent boundary layers. But then I’m the one who worked on comparing the data. When you try to do the same thing for turbulent mixing, those coefficients don’t work anymore. OK.

So, you know, I’ve said what it is and why Ken would work on it — would’ve worked on it. This is a phenomenon of scale in which there is not only no dominant scale but at any moment there’s no [laugh] dominant scale. You’re going back and forth all the time.

And there’s not even known if it’s a quantum source of the transfer, you know. It may be a — it may be describable by the Navier-Stokes equations. It may not be. We can’t do solutions that will allow us to find out. We got off the track [laugh] a little bit.

Zierler:

No, that’s — getting off the track is sort of the pleasure of the whole enterprise sometimes.

Smith:

OK, fine. I mean, look, another way to describe my work when I said before I look for transitions from being relatively limited in ability to turn data into evidence to being extraordinarily able to do so. Equally, you could describe it as what phenomenon emerged that you get a handle on everything? OK.

And in Newton’s case, it’s very simple. Kepler’s area rule if and only if centripetal force — which as you may know is Proposition 1 of the Principia. Everything else is built off of that. OK. And I mean everything else is built off of it.

Zierler:

[laugh]

Smith:

And the insight wasn’t even his; it was Hookes’, except not the if and only if part of it. Hooke asked him what trajectory does a body describe under a force directed to a center, and Newton linked it to the ellipse. It’s something like that that one’s looking for all the time, and the way I then — with something like turbulence, I asked myself, fine, what was the impediment? What was the impediment in the case of the motion of the planets?

Well, one was not having enough data, but another was — and data take a long time to get because planets — some of the planets take a long time to orbit. But the other was no physical basis for dealing with motion at all; no access to what the physics was. So you had to do everything, and it ended up being essentially curve fitting, whether you thought it was curve fitting or not. That’s what Newton changed.

That was the impediment, to get some basis for having a physics out there, and centripetal force was the basis. Turbulence, it’s very clear what the problem is. There’s no obvious point where you can truncate scale, and say everything below that can be represented by a lumped parameter. I mean, here — I don’t know what area of science you do history on.

But the Born-Oppenheimer approximation tells you you can do [laugh] molecules without paying attention to the electrons. That’s a timescale. The electrons are moving in time too — with a characteristic time around10 to the minus 15 seconds. The nuclei are responding to one another in 10 to the minus 12 seconds. And what Born-Oppenheimer tells you is the faster stuff washes out. OK?

Zierler:

Right.

Smith:

We don’t have that for turbulence. We don’t have a way of washing it out.

Zierler:

George, you mentioned AI before specifically within the context of turbulence. And I’m curious if you’ve thought in much detail about some other exciting areas where AI can really help move physics forward?

Smith:

Well, I don’t know — you’re using AI, and I did not use AI. I used computational fluid dynamics. One thing that is well-known that’s happening, everybody knows it’s happening, is statistical analysis of huge data sets, and what it’s going to show. And I’ve chosen to stay away from it. Tufts even was creating a program, and asked if I’d be willing to be involved, and I said no because I’m very suspect. [laugh]

Another way to describe much of what I’ve done on measurement is what’s the difference between a curve fit and something that has claim to being physically meaningful? As a graduate student at MIT, I took Frank Fisher’s full-year course ] — sat in his full-year graduate course on econometrics, which of course is largely regression analysis. And I know how to do regression analysis, I’ve done it, I know how to do least-squares in celestial mechanics. I know how to do least-squares with CODATA and I understand it.

But the strongest message I got from Frank Fisher, and he would say it probably once a week, econometrics is an art. [laugh] OK. And they’re trying with statistical analysis of large data sets to bypass the need for art. And I just — you know, we’ll see what comes out of it. Having large data sets can make a very definite difference. But if you don’t have theory [laugh] to deal with them, it’s not clear what you’re doing.

So, no, I don’t know what’s going to happen with computational fluid dynamics. I don’t know what’s going to happen with massive analysis of huge data sets. We’re watching it going on with pandemics. Now, as I said, I’ve gotten preoccupied with climate science for an odd reason. I taught it for the first time in 1989 looking at it as an evidence problem.

Zierler:

That’s pretty early. That’s only a year after Hansen’s famous testimony in Congress.

Smith:

Yes, that’s what sp…that’s what prompted me.

Zierler:

Oh, is that right?

Smith:

Yeah. And Stephen Schneider’s book came out, Global Warming, in 1989, so I taught it. When I was at Stanford in 2009, I became pretty good friends with Steve Schneider. I’ll just tell the anecdote.

At one point, I made a remark to the effect I find it almost unconscionable that people, you know, politicians, are taking the risks they’re doing with climate change. And Steve, who had a background as an undergraduate engineer, and had gotten to know me reasonably well, said, “You’re failure analyst, aren’t you?”, I said, “You know that” He said, “You’re risk-averse.” I said, “Yeah, of course I am. Every decent failure analyst is risk-averse. You’re not going to last long in the profession [laugh] if you’re not.”

And he said, “You know, not everybody is. That’s a personal value.” And he died a few months later. And so I’ve been teaching off and on courses on climate change ethics, and looking at evidence in climate change, and, you know, the attempts to use massive amounts of data to draw strong conclusions. And it’s — so that’s just very hard to do that. I tell my students constantly what Steve came to think after 25 years of dealing with the question, climate change is a problem in risk management. I tell them then that we can’t really establish causation for anything at the moment.

Zierler:

For anything?

Smith:

Oh, on climate, you know, climate change because it’s too complicated, short-term. There’s too much short-term fluctuation to separate. As we get a larger statistical sample, we’re increasingly being able to separate the two. But my fear is not incremental climate change.

My fear is radical climate change, the sort of thing in a paper — more recent paper of Hansen’s, I think it was around 2008 — said if we go above 350 parts per million, we are risking the future of civilization. That has been largely ignored. I’d be happy to send it to you if you wish.

Zierler:

Right. We’ve also passed the threshold.

Smith:

Yes. Oh, well, and the — you see, I’m going to teach the course around that, and the fact that it has been largely ignored. And he’s basing it on paleontological evidence. But, see, here again, the reason I came to this as I’m just musing is I asked — the question here is what’s the impediment [laugh] to getting evidence in climate change?

And the impediment of course is there are too many short-term factors to sort out [laugh] long-term effects, except over a comparatively long term. And in the case of climate change, it’s going to be too late [laugh] by the time we get high-quality evidence to counteract what’s happened. And therefore as a failure analyst, I think it is bordering on insanity.

Zierler:

Yeah, and yet, and yet…?

Smith:

And yet — and, of course, what I now teach is trying to explain why there’s no clear moral imperative to respond to climate change, and that’s a feature about moral philosophy, not about evidence, namely we’ve never had a way of dealing with technological risk except to go ahead and impose risks on people massively compared to 300 years ago. Newton lived in a largely risk-free environment. The one thing he had to worry about was smallpox and the bubonic plague. [laugh]

Zierler:

Right. [laugh] He did pretty well by socially isolating. [laugh]

Smith:

That’s right, 85 years. But he wasn’t going to get run over by a car, and an airplane wasn’t going to land on his house, etc.

Zierler:

George, I’m curious if, your interest in climate change, you know, one of the moral imperatives there is what we owe future generations. And I wonder if you’ve thought about nuclear waste in similar terms?

Smith:

Well, to an extent. I mean, I have consulted — my consulting at Oak Ridge was for bomb-grade uranium. I have as a failure analyst been brought in to one nuclear pow…two nuclear power plant failures: one in Taiwan, and one in the States. So I’ve long been preoccupied — well, you know the name Helen Caldicott?

Zierler:

No.

Smith:

You’re probably too young. She was an Australian medical doctor living in Newton, Massachusetts, who started a one-woman campaign in the late 1960s against nuclear power. You should look her up. She’s quite remarkable. [laugh]

Zierler:

OK.

Smith:

And her argument was the danger of the plants. So I have studied every major [laugh] nuclear power plant failure, and lectured on it, and actually have studied a fair that aren’t public; they’re military. But I’ve never worried that much about the waste because I just saw it and I really thought why not just shoot it off into the sun? But of course the answer is what happens if it crashes [laugh] when you shoot it off?

So, no, I have not recognized — I have not paid any attention to the issue of nuclear waste. It’s a real issue. If I were living near Yucca Flats, I’m quite confident I would pay more attention [laugh] to it. But living where I do, I don’t. But I have worried a lot about nuclear power plants and the fact that the risk in — the scale of the risk involved, and the source of the risk is almost always human error. Again, I don’t know what you know about nuclear power plants.

Under certain human errors, you have a matter of 200 to 500 seconds to correct it, or it’s too late. The temperature’s gone up so fast, you can’t recover in time. The best you can do then is hope to contain it, which Three Mile Island did. But that’s a scary situation to be in to think [laugh] that you may fail to contain a nuclear meltdown from a human error that with all the controls you have, you have to respond to correctly in such a short time period, or it’s too late.

And her argument was essentially along those lines. Her last argument was after Fukushima, so she’s still alive. I was surprised to see that she had — I think it was Fukushima. But if you look her up, you’ll see a vast literature on the subject. But, no, the answer to your question is nuclear waste is something I’ve left to other eng…to engineers to figure out how to do, because it’s not immediately threatening and instead focused on the plants and the inability to prevent failures in them.

Zierler:

Right. But as a moral — but my question was as a moral imperative to future generations in much the way that climate change…?

Smith:

I understand. Well, so is nuclear power plant failure. A large section of Ukraine is going to be useless for, you know, a couple of generations. Three Mile Island sits there as a massive mausoleum. I don’t know if you’ve ever driven by it.

Zierler:

No.

Smith:

It’s mesmerizing if you sit there seeing it. But, no, I — see, in a certain sense, I’m not even quite thinking in terms of future generations because there’s a philosophic problem about future generations. There’s a prominent philosopher who argues you can’t talk about rights for future generations because decisions you make now are going to alter who exists then.

So I’m more concerned with climate change with the very idea of human civilization disappearing. Because, you know — I’ll tell the anecdote. Scotty — what’s his last name? My old age leaves me struggling with names at times. The chaplain at Stanford used to be chaplain at Tufts, and before that he was a Scholar of the House at Yale, Scott McLennan. He’s the redhead guy in Doonesbury if you ever read Doonesbury.

Zierler:

Oh, OK.

Smith:

Having lunch with him one day, he sort of — he just sort of point blank asked , “What do you really live for?” And he looked at me and said, “I know you live for learning new things, for seeing challenging problems, etc. But isn’t there something deeper than that?” And I honestly hadn’t really thought about it.

And I sat at lunch, maybe five minutes, he let me think. And I said, “Yeah, if I live for anything, it’s the idea of a knowledge-based civilization, and the fact that we’ve gone — we’ve moved so wonderfully toward it. And the idea of it disappearing out from underneath us appalls me.” That was well before Trump.

Zierler:

[laugh]

Smith:

OK. But my view of climate change is essentially one of we’ve learned to use knowledge to manage humanity. This is a case of it. And we’re not only failing to manage it, we may be failing it in such a way to commit the very suicide of a knowledge-based civilization. And that bothers me.

Zierler:

Why?

Smith:

I have trouble thinking past my grandson, who’s four years old, for future generations. And I think most people do. But that’s the answer to your question. So nucle…the nuclear waste doesn’t pose a question for that.

Zierler:

Interesting.

Smith:

Nuclear power plants, because turbomachinery was involved in the times I’ve had to consult has always been on turbine failures. And as I say, I spent years on enrichment, off and on. That bothers me. It — you know, I don’t have a position on nuclear power, but I’m not willing to advocate it even in the face of climate change. But I’m not going to fight against it.

Zierler:

A more nuts and bolts question for you, George. Can you talk a little bit about how your position at the Dibner Institute came about, and what some of your most productive work was there?

Smith:

Yeah, I had been a fellow in ’95-’96, and I had been appointed a fellow for 2001, 2002. And Jed announced he was leaving. Jed and I are co-authors, so we’re reasonably close. And it’s a joint position MIT-Dibner. Dibner was independent of MIT. But the Director of the Dibner Institute was both half-time MIT professor in STS, and half-time at Dibner.

And I don’t know if you know Jed or you know of Jed, but Jed can be a difficult person, and had gotten into enormous conflict with the rest of STS. He and Evelyn Keller got into enormous conflict. So MIT recommended a replacement for him, and it’s public, Mary Jo Nye. The Dibners turned her down, and suddenly they needed a Director.

And Jed pointed out I was about to be a fellow, number one. Number two, I had been a prior fellow. Number three, I was doing work in the history of science, even though I was a philosopher. Number four, as an engineer, the historians of technology would welcome me, which they did. [laugh] So why don’t I become Acting Director for a year?

Zierler:

[laugh]

Smith:

And the Dibners already knew me, and so they agreed to it, with me staying at Tufts. And now I can add a little more about that. I would not have applied. I’d had people working under me when I was at Pratt&Whitney, and I decided I don’t like having people working under me because sometimes they do bad work, and you have to fire them, and it’s not a pleasant thing to do. [laugh]

So, as an engineering consultant, I had managed not to be having people report to me full-time in their career. People worked under me on projects. So I wasn’t particularly wanting an administrative position. But I had the experiences of Dibner fellow in ’95-’96. It turns out [laugh] almost every Dibner Fellow had — I’ll quote somebody from Brown University on this, and I’ll give you the circumstances in a moment — a life-fulfilling experience being a Dibner Fellow.

And I understood why, and you as a historian of science should understand this. Dibner would have Fellows come each year from totally different backgrounds. They never had a theme. They would always be picking people on the basis of their projects. And as a historian, much more so than as a philosopher, you work on some topic that most other historians look at it, and other than a small handful of people, the rest of the historians look at it and say, “Why are you doing that?” [laugh] OK. It’s not clear to them why it’s worth it.

At Dibner, the experience everybody had was to recognize the value in one another’s projects, and that fed back on yourself. OK. And it was an incredibly rewarding experience. And I had experienced it. The Dibner Fellows I would — who were with me who became long-time permanent friends, those who are still alive are still very close friends. There was something really, really special about the place.

So when I became Director, I did the following. I went to people who knew Bern, and I read everything I could about — from Bern about why he got interested in history of science, etc., and decided I would try to run the Dibner Institute in his image, which Jed had really. Jed thought of it from the point of view of I would run Dibner in Jed’s image. [laugh]

And I did not do that, though I did — for example, he would have sole say on who the next fellows were. I insisted on a committee of former fellows, with my having final say. By the way, when I was appointed, David Dibner got a letter from the then current editor of Isis saying I should be removed and be replaced immediately by a real historian of science.

Zierler:

[laugh]

Smith:

Bernie Lightman, of course. We actually ended up being cordial with one another. [laugh] But he had a point. I was not a historian of science, and it’s not clear I would appreciate the discipline the way a historian would. I think I came to appreciate the discipline more and more in the years I was there. But I thought of the Dibner Institute as the last place historians of science were primarily doing history of science, and not the social history of science.

Zierler:

What’s the clear distinction there for you, George?

Smith:

Looking at science in a broader context of society, and how the interaction between those two are occurring in contrast to looking at the development of science as a problem of evidence and internal problems. Which if you know Jed’s work, that’s all he does — or almost all he does. And, you know, Stillman Drake had resigned from History of Science Society in the ’80s because it had quit doing that kind of thing.

Bernard certainly recommended me very strongly as director of Dibner because he knew I would do that. And we continued to do that. We also had in David Bloor by the way was not only — he had been a Fellow before me, and we had become — actually before I became Director, we became good friends. When Dibner was closing, I held an event for all former Dibner fellows — 140 of the 253 attended — on the current state of history of science. And I invited David to be one of the speakers.

There’s a nice joke about that. Alex Jones was one of the speakers, and he was the first, and he described the state of the history of ancient science. And his last words were: “Ancient science has never been in a better state — better for the dozen of us.” [laugh] OK. And it — memorable. But, anyway, I felt I should nurture the Dibner Institute in the image in which I had experienced it. And I did all I could to do that, and found it enormously self-fulfilling — no, enormously fulfilling.

The six — the five and a half years I was there, which I was in my 60s at the time, probably did more to give me self-confidence in what I was interested in in doing than any time in my life, just because I saw it as part of a much larger research program, and came to appreciate the historian’s work is a community too; it’s just not a simultaneous synchronic community. It’s a diachronic community where the next historian picks up from questions left unanswered by prior historians. And we end up getting richer and richer views from multiple perspectives on history that you can’t get from any one person.

So, you know, I loved the Dibner Institute. I got a fair amount of work done there, given that I was somewhere around 40 hours a week in my office doing Dibner things. Dibner would have me give as many talks as I could possibly give, because they wanted it advertised. I think it’s a very sad moment that the Dibner Institute closed. But it came down to keeping the family together or keeping Dibner Institute together. And I granted them, I thought family staying together was more important than the Institute.

Zierler:

George, one aspect of your career we have not touched on yet is your career as a mentor. So I wonder if you can talk a little bit, you know, first in terms of your influence on undergraduates? For the kinds of undergraduates who may never interact with the kind of ideas — kinds of ideas that you want to share with them, what do you think are the most important bedrock concepts or lessons to take away, you know, in terms of adding to an undergraduate’s overall, you know, general education, and getting wise about how the world works? What are some of the most important things that you’ve learned to emphasize over your decades of undergraduate teaching?

Smith:

I’m going to give you a careful answer. One of my teachers my freshman year at Yale in Directed Studies remarked to me that what you want to be learning as an undergraduate is how to teach yourself. And the virtue of going to a university like Yale and being taught — as Yale then would not allow full professors to teach only graduate courses, as you probably realize —

Zierler:

Sure.

Smith:

— [laugh] unlike Harvard. One of the great advantages of going to a university like Yale is finding courses where the teachers teach their current research, because then you can learn how to teach yourself. And I have always thought that’s my principal function in a classroom. As much as I possibly can, always be doing some kind of research in conjunction with any course I teach so that the students can witness me doing that research, making mistakes, struggling, getting excited when I see something, etc. And I try — in every course I teach like that.

Even I — I inherited, when I came back from Dibner, the graduate course in logic, which of course you could teach sixth-graders to an extent. And even there I tried to do some research every fall on foundations of logic, just so there’s some element of my teaching myself as part of the course. The Newton course has always been my current research. Philosophy of science course has always been my current research.

I teach computation theory, and that’s the other exception where I’m the most qualified person at Tufts, and I think it’s an important subject. I apologize to students at the beginning of that course every year with the following remark: I find computation theory, Gödel’s incompleteness theorem and what came out of it, one of the most beautiful things humans ever did, so I teach it. If the music department gave me the freedom to teach Bach cantatas , I would teach that too [laugh] because it’s so beautiful.

But I openly tell them I don’t do current research in this field, and therefore I’m cheating them. But that’s how I think of it. And how I judge students is whether they pick up on that, and start trying to do research to a significant extent on their own.

And I’m proud of this book that’s going to come out because it did start as an undergraduate [laugh] single paper in a course, then as a graduating senior essay. He is now a medical doctor. He went on through medical school. But if and when you look at the preface, all the key historical discoveries he made.

I might tell you about that just as an aside. He wanted to write on Brownian motion, and the contribution it made to microphysics. And I said, “Fine. Just don’t depend on Perrin. Go back and read all the other original papers.”

Zierler:

[laugh]

Smith:

And it turned out Perrin systematically misrepresented almost everything not in his laboratory. And he discovered that, and that’s the basis of our book. It doesn’t knock Perrin’s research, but it knocks Perrin’s claim to having measured Avogadro’s number. But at any rate, I feel very good about that, even though Raghav did not go on in the field because he’s now — you know, he’s an anesthesiologist in the present moment working on the pandemic, not surprisingly, because he’s just finished his residency.

But I have a lot of former students who are in that position. They didn’t pick up from my own work. But they got something they picked up from me about the excitement of continued learning, and research that feeds continued learning. I also have a lot of students, several of them are doing current research with me. So, you know, it’s a complex combination.

Zierler:

I bet your love of learning is contagious for your students.

Smith:

Well, you know, I win prizes. I’ve won every teaching prize Tufts could give me, and it’s got nothing to do with how well I teach. It has to do with some students responding to that. [laugh]

Zierler:

Right. Now, George, without, you know — without sort of cornering you to name names, in terms of your most productive and successful collaborations with graduate students, I wonder if you can talk a little bit about some of the shared characteristics that some of your most successful graduate students have had that can sort of give an overall look as, you know, to give better insight into your style as a mentor to graduate students, the kinds of graduate students and the kinds of things that they’re interested in, and how they would be most beneficial in working with you?

Smith:

I don’t know how to answer that other than don’t take things for granted. Dig deeper. When you think you’ve got the right answer, ask in what ways could this be wrong? You know, the training of a failure analyst [laugh] I bring to everything I do. And I pick that up in my students that they — no student of mine that I collaborate with even slightly takes for granted hypothetico-deductive reasoning of evidence. They always want to look at evidence much more closely and much more historically.

One of my students has picked up from my third lecture at Stanford on seismology, and is writing [laugh] an entire book on seismology as a force — source of evidence, both for the deep structure of the Earth and on earthquakes. It will be a — it’s — you know, I know the book is going to be a major book precisely because this subject runs parallel to microphysics. And it’s a more successful story in some ways than microphysics precisely because of the continuum mechanics of wave propagation. But it’s a great success story of the 20th century. And what he’s done is look really carefully at the history of evidence in seismology, much more carefully than I could have, given other things I was doing. So I’m really grateful he’s done that.

The project I’m doing with a few people on CODATA and precision measurement of fundamental constants is actually continuing a project with — that Ken Wilson and I were starting to do, but we would not have been able to finish because of our age. Ken died in 2013. And I’m happy to see young people pick it up because I think it’s a project that needs to be done, but it’s a very demanding project. It requires a lot of people to participate, and to do a lot of hard historical work.

You can’t just look at CODATA publications and the preferred values. [laugh] You’ve got to look at all the experimental data that goes into the preferred values, which means you’ve got to look at all the error analyses in all [laugh] those experiments. And that’s a very complex story. And of course every four years there’s a new CODATA publication for all the experiments in the last four years.

Zierler:

Well, George, I think for the last portion of our conversation, I want to ask you a few broadly retrospective questions, and then some questions about contemporary and forward-looking issues. And the first is to what extent do you think some of the biggest issues in philosophy in science have changed over the course of your career as a direct result to some of the broader societal changes that have been happening in the — you know, over the course of the past 40 or 50 years? In other words, to what extent have current events as they play out in real time, how have they influenced both the major ideas in the field and the way that the major practitioners in the field have expressed themselves?

Smith:

I mean, I haven’t thought much about this. I want to rephrase that. I haven’t thought carefully about it, so I’m going to give you an answer that reflects superficial thought. And it’s all going to center on the transition away from positivist views of science, and various attempts to save them. Kuhn’s book of course had an enormous influence in undercutting the epistemic authority of science. It was the last thing in the world he wanted to do. [laugh]

Zierler:

[laugh] Right, right.

Smith:

But it did, and it did so in no small part in conjunction with the Vietnam War in academic response, (a) to the Vietnam War, (b) to the — a reaction to the growing political power of the sciences within universities. So there has been in various ways a real anti-science movement in universities in which science is presented as simply akin to another philosophic view of the world. That’s crude. But the fundamental claim is that what science gives us is a way of thinking about the world. The experimental or empirical basis for the science is much weaker than scientists claim.

And of course I’m against that, but I’m not against it programmatically. [laugh] I’m against it by showing where the evidence is extraordinarily strong. [laugh] But, yeah, I mean, when I think of from 1960 to 2…you know, there’s 60 years since I should’ve graduated as an undergraduate if I hadn’t spent two years at MIT — I mean, excuse me, two years at GE.

When I was an undergraduate, science was in no way being challenged. It’s epistemic [laugh] authority was beyond dispute. And by the time of the early ’70s, it was being challenged all over the place. And philosophers were largely responding to that challenge, trying to defend it, but without being willing to do historical work, which is the very thing Kuhn should’ve taught them. [laugh]

Zierler:

[laugh]

Smith:

That you have to do historical work. So when I started at Tufts, I concluded almost immediately that current work in philosophy of science was of no help to me. And I haven’t followed current work in philosophy of science terribly closely for that reason, because the questions I was asking, starting with idealizations, weren’t being addressed at the time. Now, increasingly, they are being addressed, but very rarely looking in long-term detail at the history of evidence.

I mean, I guess about 2005, I was invited along with Simon Schaffer and along with John [?] Heilbron to do a week-long course in Bologna for people, postdocs, and advanced graduate students in the history of science on the state of history of science. And Simon was due to be there, so my talk was aimed directly at him. And the essence of it was historians study short episodes. That’s not where science [laugh] lies.

It lies in long-term community stretching internationally and through generations in a narrow specialty. [laugh] Historians need to study that. OK. And that — Simon face-to-face — when he didn’t attend that, we had breakfast not a couple — you know, a few months later, I told him that. [laugh] And he actually said to me that’s the most interesting sociological question of all, how you can get a field like celestial mechanics extending from Ptolemy down to the present time. And my reply was [laugh] it’s not only the most interesting question, [laugh] it’s where all the epistemic authority of science lies in the constant rechecking of itself.

I mean, you know, I have a paper — I may have sent it to you — Revisiting Accepted Science — yeah. And the anti-science movement is riding on its back to some extent on looking at short-term evidence, and knowing how problematic evidence can be in the short term. We all know it’s terribly problematic. We all know physicists react too strongly to a single piece of evidence if it’s exciting. They should. [laugh] It’s advancing the field.

So the biggest change I’ve seen is philosophers of science moving somewhat in response to the anti-science movement, but my disappointment at the same time still looking not at broad enough periods of time, which is hard work. I mean, you really need groups to do that effectively. One person, unless they live a very long time, is limited in what they can do. But what bothers me now — I mean, Naomi Oreskes is trying to do something about this almost single-handedly — is the extent to which the authority of science [laugh] has been lost in the United States politically. It just — it totally appalls me.

Zierler:

And this of course is having catastrophic implications now during our current pandemic.

Smith:

Of course. No, I mean, I see it all the time. I see it in climate change. I see it in emissions. You know, it’s all over the place. But it’s been more prominent in this pandemic than it has ever been before. Now, Naomi’s line of argument is to trust consensus in science. That’s not my line of argument. [laugh] My line of argument is to look at the history of the evidence in a field, and see how deeply — deep the evidence has gone.

But it scares the hell out of me in many ways to see the lack of trust in science. I mean, it’s due to society’s different way. I was too young to take General Science at Harvard. But Bernard of course was one of the founders as, you know, Conant and Kuhn were founders of it. Conant had seen the need for people outside science to understand how science works, and so they created the General Science program. If you’ve never done it, you should get the two volumes of monographs that were used in the courses because they’re extraordinary.

Zierler:

OK. That’s great.

Smith:

But when you look at Leviathan and the Air-Pump, they tell you that that book is intended to be a corrective to the General Science picture of science. And it is because the picture that’s presented there is how once certain evid…once the right idea is put forward, the evidence falls into place. That’s the picture you get from the General Science monographs. And, Simon — I’ve never met Shapin and I’ve never taken the trouble to, even though we’re neighbors, [laugh] but I did — I do feel I know Simon reasonably well. They had a point, but they exaggerated the point too much [laugh] in the other direction by not looking at the whole history .

I once had breakfast with Harry Collins and granted him a problematic character of current evidence, but then pointed out the long run. And Harry said to me, “Of course in the long run these things can really work.” [laugh] To which I then said, “Harry, why don’t you write about it?” OK. So, yeah, I’ve seen a transformation, but it’s — the transformation I see is philosophy of science has become internally focused, and as a result on the whole has become ineffective in responding to the anti-science movement. And that disappoints me greatly.

Zierler:

George, is that to say, I mean —

Smith:

That’s a superficial answer. That’s not something I’ve thought through carefully. If you’d given me two weeks —

Zierler:

[laugh]

Smith:

— you might’ve gotten a different answer.

Zierler:

That’s the beauty of oral history. You’re thinking on your feet, you know.

Smith:

Fair enough.

Zierler:

I want to ask, you know, in that vein about these distressing trend lines that you see — you know, a theme of our conversation of course is on the absolute formative development that Kuhn had on you, right. Is that to say in your mind that — is Kuhn more relevant than ever today, even then when you were first exposed to this work 40-plus years ago? Are there things that Kuhn never could’ve thought of himself, and yet the way that he thought and the way that he helped you establish your identification of the most important issues, are they in a sense even more relevant today and more necessary than they might’ve even been even a half a century ago?

Smith:

That’s a good question. I mean, Tom’s book was very radical. You must realize that. I said he had me teach the last two weeks of his course on Newton in 1983. And I said as a preliminary, we have to read certain Kepler. We were standing at the time.

You know, Kuhn said, “Why Kepler?” “Because you can’t understand the evidence in the Principia without Kepler.” Tom was about six-four, six-three, six-four. He threw his hands up into the — toward the ceiling, and actually said, “Oh, evidence, that.”

Zierler:

[laugh]

Smith:

OK. Tom was the ultimate analyst of conceptual development, and he was very good at it. Read his book on quantum black-body. It’s a masterpiece of conceptual analysis. Tom knew next to nothing about evidence. He asked me to join him that last year of his lif because I gave the opening talk at Dibner Institute, and it was about Huygens’s four significant figure measurements of surface gravity, and why they were so heavily validated, and why they continue to — the same method continued till 1950.

And, you know, at that point, he decided I was worth something. [laugh] But there just hasn’t been much attention to evidence. And my own view is any epistemic authority any science has has to lie in the evidence, but the evidence has a long history to it that has to be dug out because most of it happens without anybody noting it’s happened.

I mean, I revere review articles. Good review articles I think of as the most valuable thing going on in science, precisely because they step back and say, “Here’s what we don’t know and why we don’t know it. And here’s what’s relatively secure.” There are a lot of poorly written review articles.

The best review article I have ever read is actually a book by Steve Weinberg after years of not being in cosmology. He came back and wrote a book on the current state of cosmology, which is a very disappointing book in the sense that [laugh] we haven’t gotten anywhere. [laugh] “Here’s the upshot in the years I’ve been away, and here’s why.” [laugh]

But I — my reading — instead of reading a lot of philosophy, I read annual reviews. I like review articles all the time. Those are the things I want to see — and good histories. So I’ve been reading a lot of history on quantum field theory by people like Sam Schweber and Tomonagawhere I feel they know the science and the evidence for it well enough that what they say can be trusted.

Look, I’ve had — I’ve been very lucky to have a 16-year virtually weekly conversation with Ken Wilson from 1996 to 2012, and to have almost as long-running a — ongoing luncheons with Sam Schweber. And they’re both — the new book is dedicated to the two of them. Schweber’s the one who told Ken Wilson he should meet me.

And I tend to view science through Ken’s eyes and in his father’s eyes. I don’t know if you know who his father was, E. Bright Wilson. E. Bright Wilson was a chemist at Harvard. As a graduate student at Caltech, he co-authored — he actually wrote it — the Pauling and Wilson book on — textbook on quantum mechanics. And he was a quantum chemist of great renown at Harvard.

And I never met him, but Ken grew up with him, and I know a lot about him. But Wilson of course saw sciences at all times. Here is a problem. How do we make progress on it? You may not know this. When Ken graduated, he was a junior fellow, and got hired at Cornell. He decided he wanted to work on a problem that would take 10 years. And his father told him, “This is going to crucify your career.” [laugh]

Zierler:

Yeah. [laugh]

Smith:

“Don’t do this.” But he did it, OK. And he got tenure at Cornell [laugh] as prestigious a department as it was in the country at the time on the basis of one published paper. Three years later, he published the Renormalization Group [laugh] which he had been working on that whole time.

Weinberg has been working on the same kind of problems ever since he did the first text on general relativity following the discovery of the background radiation. And if you recall, it’s general relativity in cosmology, that text from the ’60s. Kuhn worked on the same question his whole life. I feel very comfortable with people like that and try to emulate. I don’t know if that helps but that —

Zierler:

Absolutely.

Smith:

That says probably the most about me. People who stay with one question, and really try to come to full control of it, I understand.

Zierler:

Yeah. Well, George, it’s just my nature, you know, we focused in the past several minutes on some of the broad macroscopic changes that are very disconcerting. And so, you know, to round out our conversation, I want to ask you for my last question, forward-looking question, that would ask you to draw on your powers of extrapolation over your long and distinguished career. And that is, you know, in addition to the topics that still engage your interest and your imagination, more broadly speaking, you know, from the perspective of philosophy and science, what are some of the trend lines that you’re optimistic about, that you’re excited about, that you see as promising for really making constructive and productive change, both in the academy and in society writ large?

Smith:

Again, I’m not sure how to answer. I mean, we’ve been talking — I’ve been talking about my work. You’ve interviewed Allan [Franklin]. Allan made a huge difference, you would think, to philosophy of science by finally getting people to look at experiment. Are people looking at experiment today? Very little. OK. Why? Because it’s hard work.

Zierler:

Right.

Smith:

And that’s what I hope will happen in the relatively nearer future. I’m about to say what single trend I most think should change. I hope people start looking from outside of science at science, whether it be historians or philosophers willing to dig into the science much deeper than they’re prepared to from their undergraduate education.

Undergraduate education focuses overwhelmingly on theory because you have to know theory to go on to be an engineer, to be any number of other things. The idea that theory is the ultimate goal of scientific knowledge as a result has become, at least in philosophy of science, the prevalent view. Allan tried to change that. I’ve tried to change it in a different way from Allan. My students are trying to change that, the ones I’m working with on fundamental constants.

And I’ll just say what the view I would prefer to see come. If you read Closing the Loop, it ends closing the loop. If you ask the question, what do we know now that Galileo didn’t know?, the answer — my answer is literally millions of details in the world that make a difference, and to reasonably high approximation what differences they make. Theory is an indispensable instrument for getting there. But those are final words in the way the theory need not be. Theory need not be too true to do that.

And I’m hoping that there will be somewhat of a shift away from thinking of science as what we learn in undergraduate classrooms, and thinking instead on what the theory has enabled us to learn about the world. And that’s not the way you went through undergraduate classrooms. I don’t know how many sciences you took. You learned about theory to a very heavy extent. And I think that’s missing the reach achievement.

But I didn’t write it. That’s — you know, you brought back Allan’s work because Allan’s whole career has been one of trying to get people to [laugh] recognize not only just coming out of experiments; experiments have to be looked at very, very carefully to see how they work, instead of just taking for granted the published results are the published events, they’re evidence, and go on. And how many historians have picked up on Allan’s work, even Peter, who started doing it?

Zierler:

Well, I hope to have something to do with changing that trajectory. That’s all I can say. [laugh]

Smith:

Right. I hope this has not been a waste for you.

Zierler:

Not even a little bit. Not even a little bit. George, I was just going to say quite the opposite. I’m so glad that we connected. And, you know, you’re bringing perspectives that I think are so important for the physics field, the larger, broader physics community to hear and to think about. And in some small way, I hope that our discussion, you know, does exactly that. So it’s been a pleasure speaking with, and I want to thank you so much for your time today.

Smith:

Oh, it was a great pleasure for me because I got to reminisce. People in their 80s enjoy reminiscing.

Zierler:

That’s right. That’s right.