Allan Franklin

Zierler:

OK. This is David Zierler, oral historian for the American Institute of Physics. It is May 12th, 2020. It’s my great pleasure to be here with Professor Allan Franklin. Allan, thank you so much for being with me today.

Franklin:

Oh, it’s a great honor for me to be selected to be in the AIP oral history project.

Zierler:

Wonderful. OK. So to start, please tell me your title and institutional affiliation.

Franklin:

I am Professor Emeritus of Physics in the Department of Physics, University of Colorado.

Zierler:

OK, and let’s now take it right back to the beginning. Tell me about your birthplace and your family background.

Franklin:

OK. I was born in Brooklyn in 1938.

Zierler:

I guessed Brooklyn. I didn’t want to say it, but I guessed Brooklyn.

Franklin:

The accent is still with me.

Zierler:

And it’s very near and dear to me. My parents are from Brooklyn also.

Franklin:

Well, it’s interesting. I taught at the City University in 1974/75. And they did not identify me as a native New Yorker.

Zierler:

[laugh]

Franklin:

There was enough overlay that they asked me where I was from.

Zierler:

Ah [laugh] that’s great.

Franklin:

My father was a real estate manager. He managed apartment houses on the Upper East Side. My mother was a homemaker, a housewife.

Zierler:

What neighborhood did you grow up in?

Franklin:

Bensonhurst.

Zierler:

OK, hallowed ground. My father-in-law’s from Bensonhurst. Are your parents native New Yorkers?

Franklin:

My mother was born in New York and my father in Haverhill, Massachusetts. He grew up in New York.

Zierler:

And what about their parents?

Franklin:

They were all immigrants from Eastern Europe, Russia, Lithuania. This was the big early 20th century immigration.

Zierler:

Of course. Now, did you go to PS public schools throughout?

Franklin:

Yes, I went to PS 186, Seth Low Junior High School, and New Utrecht High School.

Zierler:

New Utrecht High School? OK. Helen Berman, do you know Helen Berman by any chance?

Franklin:

I don’t think so.

Zierler:

She’s a physicist. She went to New Utrecht. I talked to her a few weeks ago. Anyway, so New Utrecht, did you consider one of the specialized schools like Brooklyn Tech or Bronx High School of Science?

Franklin:

Actually, I considered Stuyvesant, but I didn’t want the hour commute each way.

Zierler:

Right. [laugh]

Franklin:

And because that would interfere with after-school athletics.

Zierler:

I see. What did you play?

Franklin:

Oh, everything: basketball, softball, hockey on roller skates, touch football.

Zierler:

Now, when did you start to show aptitude in math and science?

Franklin:

I think essentially as soon as I entered public school, always good in math and science. But I was actually pretty good in everything. I was a born student, if you will. I liked school.

Zierler:

So what colleges did you apply to?

Franklin:

I applied to Columbia, Brooklyn College, and Rutgers.

Zierler:

OK, and where’d you did end up going?

Franklin:

Columbia.

Zierler:

It seems like the obvious choice.

Franklin:

There was a teacher, an English teacher at New Utrecht, Mr. Arnold Horowitz, who influenced all of us in a very good way. And he went to Columbia. So if you were a very good student at New Utrecht, you didn’t really consider any other schools.

Zierler:

[laugh]

Franklin:

Brooklyn College and Rutgers were strictly backups. I wanted to go to Columbia.

Zierler:

Right. Now, did you make the commute up to Columbia, or did you live there?

Franklin:

No, I was fortunate to win a scholarship, which enabled me to live on campus.

Zierler:

So what year did you arrive at Columbia? What would that have been?

Franklin:

‘55.

Zierler:

OK, ‘55. And did you declare the major in physics right away, or that came later on?

Franklin:

Yes, I declared a physics major, but I wasn’t sure whether I wanted to major in physics or mathematics. And that stopped in my sophomore year when I took my first really abstract math course, and I knew I was going to be an experimental physicist.

Zierler:

Right. [laugh] So you went the whole way over to experimental physics from abstract math?

Franklin:

Well, I always wanted experiment rather than theory. I wasn’t particularly strong in theory, in my own view. And so if I was going to do physics, it was going to be experiment.

Zierler:

Now, when you were a kid, were you a tinkerer? Would you mess around with things?

Franklin:

No, I didn’t do that at all. I’m hopeless at home improvements, even small ones.

Zierler:

So how’d you develop an interest and talent in the experimental side?

Franklin:

I don’t actually know. I was pretty klutzy in lab as an undergraduate, but I liked it. I liked the idea of learning about things in the world, you know, if you will, learning about nature. And that appealed to me more, and so that was where I decided.

Zierler:

Now, Sputnik happened while you were an undergraduate. Do you remember what kind of an impact that might’ve had on you?

Franklin:

Very little. I was fortunate as an undergraduate that the physics department at Columbia made it possible for us to work in research labs as an undergraduate. I did that for two years.

Zierler:

Which labs did you work in?

Franklin:

I worked with Charlie Townes in his then maser lab. This is before the lasers. I didn’t do much there. But more importantly, I worked with Eugene Commins, Gene Commins, who was just a grad student, then an instructor. He worked with Polykarp Kusch. So I was in with two Nobel Prize winners.

Zierler:

Yeah, that’s a good spot to be in.

Franklin:

He was the guy I worked most closely with, and he was superb to work with.

Zierler:

Now, which of the labs would you say was more formative in, you know, defining your own identity as a physicist?

Franklin:

Working with Gene.

Zierler:

Why so?

Franklin:

Gene was—he later went on to be professor at Berkeley, and a member of the National Academy. But Gene was kind of an ideal experimenter. I always wanted to take data. And Gene would not take data until he was absolutely sure the apparatus was working properly.

Zierler:

That’s interesting. What do you—what did that say about his work style and his process?

Franklin:

He was careful of—the thing that is probably my most important contribution to philosophy of science is the epistemology of experiment. The arguments that people use to say, “Yeah, we did make it,” it’s not on faith. There are good reasons to believe our result. But Gene—we were once working, and I wanted to take data, and Gene wasn’t sure that the apparatus was working correctly. And he said to me, although he denied it later, “Any fool can take data. It’s taking good data that counts.”

Zierler:

Right. [laugh]

Franklin:

And that actually appeared in the title of one of my papers because I put it in as just a tagline under the title, and they mis-typeset it. So the paper is Selectivity and the Production of Experimental Results. “Any fool can take data. It’s taking good data that counts.”

Zierler:

[laugh]

Franklin:

So Gene was, you know, in some sense a kind of ideal experimenter… In graduate school I also had benefit of working with really good experimenters.

Zierler:

Now it sounds like as an undergraduate, you developed a uniquely close relationship with a very eminent physicist. Did he have this—were you kind of special in that regard? Did he take on undergraduate students in such a substantive way generally?

Franklin:

Oh, Gene?

Zierler:

Yeah.

Franklin:

He was then—when I first worked with him, he was a grad student, and then he was an instructor. He worked under—with Polykarp Kusch. It was Kusch’s lab. But Gene just liked doing it. And they made you feel a part of the lab. I made use of my experience there. I’ve written chapters about [laugh] some of them in my later work. It was just very formative, if you will. I was sorry, in some sense that when—after I graduated, they wouldn’t let me work in the lab anymore. They needed the spaces for other students.

Zierler:

Right. Now, did you have a senior thesis?

Franklin:

No, they didn’t require a thesis in those days. There was no honors program. You found out about honors when you got your diploma. It was a surprise.

Zierler:

And were there any relevant summer internships during your undergraduate years?

Franklin:

I did work in the summers with Gene.

Zierler:

Oh, yeah, you kept that up?

Franklin:

I spent a summer out at Brookhaven.

Zierler:

Now, at what point did you figure that you wanted to pursue graduate school? Was that sort of baked in right from the beginning, would you say?

Franklin:

As soon as I started college—it was never a question. One thing we used to worry about is what happens if you’re working on a thesis, and somebody publishes first? We used to sometimes discuss that. But, yeah, no, it was always going to be graduate school.

Zierler:

And in terms of continuing on in experimental physics, did that influence the kinds of schools that you applied to, and the kinds of professors you wanted to work with?

Franklin:

The schools I wanted to apply to, I knew I wanted to do experimental particle physics, and so I chose places that had accelerators. I applied to Stanford, Rochester which had a cyclotron in those days, and Cornell which had an electron synchrotron. I also applied to Columbia because I knew I would get in. And in fact, I was—Gene stated that he would take me on as a student if I came. But I wanted to do particle physics and—

Zierler:

Now, I’ve heard—I mean, there’s the one model that says, you know, for undergraduates, you should move on. You should not stay for graduate school. And there’s the other model that says why would you go anywhere else? You’re here, right. So I wonder what was the more dominant way of thinking at Columbia?

Franklin:

They, at least the professors I talked to, never either encouraged me or discouraged me from either staying or going. But I wanted a change. I’ve lived in New York City [laugh] for my whole life, and I wanted a different place.

Zierler:

So where did you end up going?

Franklin:

Cornell.

Zierler:

OK, and what was the deciding factor there?

Franklin:

They had an accelerator, and it was on campus. I wouldn’t have to travel. And it was a good school.

Zierler:

And so you would’ve entered Cornell when? 1959?

Franklin:

1959

Zierler:

And so what—tell me a little bit about your impressions when you got to Cornell. What was going on in the physics department then? What were the big questions that some of the eminent professors were working on?

Franklin:

Well, I actually had an—at Cornell, the system was different from other schools. You had a special committee, which essentially determined your whole graduate career, It was made up of three professors and you had to pick one—from experimental physics. If you picked experiment, you had to pick theory [laugh] and then another one, and the normal one was mathematics. So those were the three professors.

At the time, we had the electrons at one point, 1.3 GeV electron synchrotron. R. R. Wilson, Bob Wilson, was the director of the lab, so there was all sorts of photon production, electron scattering going on at high-energy physics.

Zierler:

Now, what was Wilson working on at that point?

Franklin:

They were doing electron scattering off protons, form factors of the proton. Robert Brout was there, who later did this important work on critical phenomena. He probably would’ve won the Nobel Prize when Englert won it, but he unfortunately passed away before.

And so there was—and then I remember there was Robert Silsbee was doing condensed-matter physics. But I essentially knew I wanted to be at the Newman Lab, and so that’s where I worked. Hans Bethe was there, but I had no interactions with him except at the Friday afternoon journal club meetings. So I had a great advisor, by the way.

Zierler:

Yeah. What was the process—before we get to who it was, what was the process in terms of picking an advisor? Would you do work, and then ask around? How did that work?

Franklin:

No, I did it—when I was—knew I was going to go to Cornell, I went around at Columbia, and asked people like Jack Steinberger who I should work with. And he knew I was a reasonably good student, and said, “Oh, Al Silverman’s a good guy to work for.”

And you had to pick an advisor initially. It didn’t mean you stayed with them. But I went to Al, and said, “I’d like to work with you. Would you be my advisor?” And he said, “Yes.”

Zierler:

Oh, so from day one, you developed the advisor relationship? Interesting.

Franklin:

And Al was a great advisor. He treated us as individuals when there were—I worked with two other grad students, and we were all quite different, and he treated us the way we needed to be treated.

Zierler:

And what were Al Silverman’s—what were his major research projects?

Franklin:

Well, we—when I worked with him, it was on photo production of pi-meson pairs. And I worked on—my dissertation was photo production of rho-mesons.

Zierler:

Now, was this an outgrowth of his research, or this was your own independent research question?

Franklin:

It was in the group. The group had—the two guys before me higher on the totem pole you went up—worked on the photo production of pi pairs. When I got there—when I got finally to work on my own work, it was rho-mesons. And there were—it was a natural progression of the group, and I certainly didn’t choose it. And it was, you know, what Al determined.

But he was—he knew I had an interest in philosophy of science. I told him. And he allowed me to take a graduate philosophy of science course as part of my graduate career. I have two courses in philosophy, no courses in history and science, but two in philosophy of science; one is an undergraduate, and one is a graduate. So I’m uneducated in what I—

Zierler:

[laugh]

Franklin:

—mostly what I’ve worked on.

Zierler:

[laugh]

Franklin:

Actually, that’s really an exaggeration. I have had informal education by a huge number of people who have been very supportive and very nice.

Zierler:

Now, who was on your thesis committee?

Franklin:

Al Silverman, Toichiro Kinoshita and to be honest, I don’t remember the math advisor because he was my regular math advisor. Wolfgang Fuchs was on leave that semester when I defended my thesis, so somebody else just came in at the last minute. So I didn’t actually—I think the only time I saw him was at the dissertation defense.

Zierler:

[laugh] Now, did you—had you worked closely with Toichiro, or he just came on for the defense?

Franklin:

I took courses with him. That was my connection with him mostly.

Zierler:

And what—do you remember what he was working on in those days?

Franklin:

He was calculating, you know, corrections to the fine structure constant…that was his big work. He was, you know, doing quantum electrodynamics calculations more, you know, finer, higher order corrections to the fine structure constant.

Zierler:

And do you know—had he been at Cornell for a while by the time you interacted with him, or was he more closely new?

Franklin:

I assumed he had been there for a while.

Zierler:

Now, to the extent that you thought about such things then or now, what did you see as your primary contributions with your dissertation?

Franklin:

I did pretty much everything. I took the data. I helped build the apparatus. We used thin-plate spark chambers. And we built the first ones at Cornell—these were with thin aluminum foils—armed with a Review of Scientific Instruments article by Gerry O’Neill on how you did it. And this was where you had the plastic frames, and thin aluminum foil. And the question was how did you get them flat, which you needed. And the way that it was suggested was you cooled it down in a refrigerator room, and then when they expanded to room temperature, the plastic expanded more than the aluminum, and so it became very flat. Our refrigerator room was where they stored garbage at the home economics school—

Zierler:

[laugh]

Franklin:

—which was right next to Newman lab. [laugh] So we used to go—Charlie Sinclair and I used to go over there and glued the plates in the refrigerator room let them go for a few days, take them out, let them warm up to room temperature, and they were flat.

Zierler:

Yeah. So what year did you graduate?

Franklin:

January 1965.

Zierler:

January 1965. OK. And what are your options at that point? What are you thinking about doing next? A postdoc?

Franklin:

Yeah, and Al arranged for me, you know, to—at least to talk with Gerry O’Neill down at Princeton at the Princeton-Penn Accelerator. And I got the job, and I worked with the Mann-O’Neill collaboration for two and a half years. I also wanted to get some teaching experience, and so for my last year, I was an instructor working with Eric Rogers, who was an awe-inspiring teacher.

Zierler:

Oh, yeah?

Franklin:

Oh, yeah.

Zierler:

How so?

Franklin:

He was just clear. He was prepared. He was an older Englishman. And to give you an idea of how he appeared… At a party at his home, a Halloween party, costume, and he appeared—I think it was as the Mad Hatter. And everybody thought it was, yeah, fun. That makes sense.

Zierler:

[laugh]

Franklin:

But he was—in fact the Princeton teaching of introductory physics, the year I was instructor, was just superb. It was Eric, and there was also Aaron Lemonick, who was associate director of the Princeton-Penn Accelerator, who was another superb teacher.

Zierler:

Yeah. Now did you—

Franklin:

I used to sit in Eric’s lectures, so I know how good he was.

Zierler:

Did you have any involvement with the Princeton Accelerator?

Franklin:

Yeah, that’s where I worked. I worked with the Mann-O’Neill collaboration at the PPA.

Zierler:

And what were the big research questions around that project?

Franklin:

Well, it wasn’t at the PPA. The big thing that was going on, that had actually occurred before I got there was a Fitch and Cronin CP violation was done in ‘63, ‘64. We were working on K-meson decays. We were looking for the K+e2C2[?] branching ratio. It’s a very small and branching ratio. And we were, we thought, the first ones to actually get a number as opposed to a limit on the branching ratio.

Zierler:

And what does that mean, getting a number as opposed to getting a limit?

Franklin:

Well, if you don’t see—the way you do it, you find how many events of the kind you’re looking for comparing to all the K-meson decays. And the way you set a limit was, well, suppose you don’t see any. So you say, well, if I saw one, this would be the limit on the branching ratio.

We saw six, and so we could set a limit of—what was it? 2.1 plus or minus some huge numbers like 1.8 minus 1.3 times 10 to the -5. We thought that was—I remember how pleased we were when we got one event that fit in the right bin. So that—and then we worked on some other projects.

Essentially we then looked at the—it was actually part of this whole series of experiments on K+ mesons that started before I got there. We looked at the energy spectrum…they looked at the energy spectrum in K+e3 decay, the form factor in K+e3. We looked at K+e3. It was—I actually again made use of that. I once wrote a paper called Instrumental Loyalty and the Recycling of Expertise.

Zierler:

[laugh] That’s great.

Franklin:

[laugh] well, it’s different now. But in high-energy phys…in physics in general, you don’t ask yourself necessarily, “What’s the best experiment I can do?” You ask “What’s the best experiment I can do with the equipment that I have, or with a small modification or—and what I know how to do? And so we, as a group, the Mann-O’Neill collaboration were just doing K+ branching ratio experiment type stuff.

Zierler:

And how did you see this work fitting in more broadly to what high-energy physics was trying to achieve at that time?

Franklin:

Well, this was on—this was the first test of the V-A theory of weak interactions in strangeness changing decays. V-A had already been well-established by then. But nobody had ever looked at it in strangeness changing weak decays, and that’s what we were doing. Because there was a very specific prediction of—V-A said it was going to be like 10 to the -5. But other theories gave much different answers.

Zierler:

Now, did you have an opportunity to do any teaching at Princeton?

Franklin:

Yes, I went over to talk with Eric Rogers, and so my last year I was an instructor working with Eric as teaching recitation lab. And Eric went on leave the spring semester, and he allowed three of us to take over the course. And so I actually got a chance to lecture in a big course for three weeks.

Zierler:

Oh, wow. How did it go?

Franklin:

Well, they didn’t walk out in large numbers.

Zierler:

[laugh]

Franklin:

[laugh] But, you know, Eric was just, you know, very supportive, when I got the next job at Colorado, he told me who I should talk to, and things that I should worry about.

Zierler:

Yeah. So I’m curious, coming from Cornell, did Princeton—did physics at Princeton feel like a very different kind of place, or was it largely similar to the department at Cornell?

Franklin:

It was similar, you know. Again, I was essentially—for the first year and a half, I was out at the PPA. I never went to the department. And when I was an instructor, I had more interactions with the department.

Princeton was a more formal place than Cornell was. At Cornell, everybody was at highest level Mister. But at Princeton and the PPA, it was Doctor. It was an interesting distinction. When I went to the PPA, they had a weird system. You didn’t call somebody else, because you’re all around the accelerator.

You could be anywhere. You called the central admin…a central telephone person said, “I want to speak to, say, Ken McFarlane. I’m at extension such-and-such.” And then they would announce over the PA, “Ken McFarlane call extension 5147.” But the person who did that would be quite clear that, “Would Dr. McFarlane call?”

And I’d been there a few months, and she found out I had a PhD, and she said, “Well, why didn’t you tell me?” I said, “Well, you know, [laugh] it didn’t seem”—

Zierler:

[laugh]

Franklin:

And the same thing was true in the department. When I took over for doing part of the course for Eric, I was—one of my tasks was—Eric required a term paper. And so that was my job. And so I took what Eric had written instructions for writing your term papers, and said, “If you have any questions, see Allan Franklin,” and because it said “Eric Rogers”.

And I just—and the secretary said to me, “Well, why aren’t you saying Dr. Franklin?” I said, “Well, if it’s good enough for Professor Rogers not to say it, I thought it was good enough for me.” “But Professor Rogers doesn’t have a PhD.”

Zierler:

[laugh]

Franklin:

Oh, it was—that was the difference. But certainly in terms of the interactions with fellow physicists, it was pretty much the same.

Zierler:

And what exactly was the arrangement between PPA and the department? How closely linked were they?

Franklin:

Well, the professors worked at the PPA. You know, they were just at different sites. It was Cornell. The lab of nuclear studies then was in Newman Lab, which was just a walk away from Rockefeller Hall. The difference is you had to drive from one to the other.

Zierler:

Right. And I’m curious, did you spend any time at the institute during those years?

Franklin:

No, none at all.

Zierler:

That was a separate world?

Franklin:

Yeah.

Zierler:

Yeah. And so when did the postdoc wrap up? What year would this have been?

Franklin:

It ended in the summer of 1967, and then I came to the University of Colorado.

Zierler:

Right. Now, when you were on the job market, how was it in those years? Were there a lot of good jobs available, or were things tightening up at that point?

Franklin:

It was a very different world.

Zierler:

Yeah. [laugh]

Franklin:

I wrote nine letters applying for jobs, and received four job offers, and I was upset—

Zierler:

[laugh]

Franklin:

—that it was only four.

Zierler:

[laugh] Four and out of nine. Where did you get offers?

Franklin:

Colorado, I was offered the Fermi Fellowship at Chicago, I was offered a research assistant professorship at Illinois, and I was offered a position at Northeastern.

Zierler:

And Colorado was a tenure line offer from the beginning?

Franklin:

That was the best—that was the reason I chose Colorado because it was a tenure-track position.

Zierler:

So I’m curious, Colorado at that point, what was your sense of how established the department was? Were they looking to build, were they already, you know, pretty high up in stature? What was your sense?

Franklin:

They had just had a—the NSF had a program, Centers of Potential Excellence. And so they had been hiring a fair number of people. And I got hired at the very end of it. I think I was almost the last person they hired on that program.

Zierler:

So it was NSF money initially that paid your salary?

Franklin:

No, no, but I think—yeah, I think in some odd way it did. I never looked into it. I was just happy to have a job.

Zierler:

Sure. [laugh]

Franklin:

And to be honest, the department was nowhere near as good as it is now. I mean, it was built later, starting in late ‘80s, early ‘90s.

Zierler:

I mean, I’m just thinking more generally, Boulder in those days, it must’ve been like a small college town, right?

Franklin:

Yeah, it was—and they had a summer institute, which—a Theoretical Physics Institute. But, yeah, it was a different world from—I’d been, you know, in the Ivy League my whole career up till then, and it seemed somewhat different. But the department was nowhere near the quality that it is now.

Zierler:

Now, would you say—was there a particular focus in the kinds of physics that Colorado was looking to build up, or was it across the board, everything?

Franklin:

Well, what they—I only knew a few of the people who were hired, and those were theoretical physicists, mathematical physicists. They were—the chair of the department who had enormous influence was a mathematical physicist, and he wanted people similar to himself.

Zierler:

And who was that? Who was the chair then?

Franklin:

Wes Britten.

Zierler:

OK.

Franklin:

And they hired Carl Iddings I know and Joe Dreitlein. They were both theorists. And there were at least two other junior high-energy experimentalists in the department. There was also JILA then, the Joint Institute, which of course now is the world-class place for doing atomic physics.

Zierler:

Right. And how well-developed was it when you arrived?

Franklin:

It was reasonably well-developed. I think it was probably the strongest part because people had joint appointments. We also had a big nuclear physics group. We had a cyclotron that was working at Colorado then.

But I think it would be fair to say that JILA was the strongest part of the department then. There was more—there were a few more astrophysicists there, then the astrophysicists split off a little later. But it was a good department, but it’s better now.

Zierler:

Was JILA a draw for you specifically, or it was just nice to have that there?

Franklin:

It was just nice. You wanted to be at a good place. Now, I knew it wasn’t going to be Cornell or Princeton.

Zierler:

Yeah. So in terms of this being, you know, your first tenure-line job, were you looking to build on the previous research projects that you had done, or were you looking to sort of switch up directions a little bit?

Franklin:

Well, the—I had done only spark chamber physics at both Cornell and Princeton. And Colorado was all bubble chambers. So I actually had to learn a new technique, and essentially work on whatever was going on.

Zierler:

So that begs the question, why not build your own spark chamber? Too big?

Franklin:

Too big a project, and there was—I had no—we came in on a research contract already, and I was expected to be part of it, so it was…

Zierler:

So what’s the learning curve in terms of coming from a spark chamber background to bubble chambers?

Franklin:

Not as much as you would think. In fact, Peter Galison, who at some point you will probably interview—

Zierler:

Sure.

Franklin:

—wrote a whole book about that, Image and Logic, about the two traditions. And I didn’t—there were things I needed to learn about bubble chamber analysis, and such. But it wasn’t a huge learning curve. It was a few months’ worth of work. And ultimately, I actually did one experiment on my own with a postdoc, using bubble chambers.

Zierler:

Now, did you get a sense of why Colorado embraced bubble chambers, where that came from?

Franklin:

Well, a lot—well, first of all, the bubble chambers were the big high-energy device in those days. The Alvarez Group at Berkeley, you know, kind of dominated. They had more events. The only thing you could hope for was that you weren’t working on something they were working on.

Zierler:

So I guess then we can flip that question around. Why were Cornell and Princeton not using bubble chambers?

Franklin:

That, you know, was way above my pay grade.

Zierler:

[laugh]

Franklin:

And, you know, the thing about—the bubble chamber was not—you took what you got. You ran a beam of protons into the bubble chamber, and looked at what you got. Spark chambers—and this Peter talks about in his book—you could assemble counters to decide which events you would look at. And so you were much more selective.

So you didn’t get quite as many events, but you did get more of the kind you were looking for. Like, when I did my dissertation, I worked it so that we detected a proton and a pion. I didn’t take everything that when the gamma rays hit the proton came off. I just—and also you had a much smaller solid angle.

Zierler:

So in terms of what each can do, is it fair to say that a spark chamber and a bubble chamber get the same—can get the same data through different means?

Franklin:

Yeah, but the bubble chamber gets way more, and much different. You know, you have to be much more selective in analyzing. Of course now with the kinds of chambers we use now. And the kind of monstrous electronics you have, and counters, I mean, the new things—essentially, you have electronic bubble chambers, although there is an enormous amount of selection of events to record. I had the privilege and the fun of actually seeing the CMS detector open at CERN about a year and a half ago. And, you know, we were cavemen.

Zierler:

Right. [laugh]

Franklin:

[laugh] I mean, for me, it was like visiting a cathedral to see that. I mean, you know, it just—but now—and they can do, you know, incredible things with—they have different kinds of counters, and different chambers. It’s—and they record digitally, and so you’re much faster. Even I’ve counted up that all the events I had in my dissertation would’ve taken 2 minutes at CMS—and it took us months.

Zierler:

Right. Well, you were working with what you had available at the time.

Franklin:

That’s right, but it was a different world. [laugh]

Zierler:

Can you describe Millikan’s oil drop experiment, and what you were working on with that?

Franklin:

You mean in the—the oil drop experiment is fairly standard. You have droplets between two charged plates, voltage applied, and you don’t apply the voltage and let them fall under gravity, and time how long it goes for a certain distance. Then you turn on the field, and it goes up a certain distance. Then you turn off the field, and it goes down.

And you keep it going as long as you got—Millikan, by the way, was absolutely a master at this. He kept one drop going for four and a half hours. I was lucky when I did it, and you do it in just a standard lab, if I could get it going up and down five or six times. And that was relatively straightforward. But, you know, we do it in sophomore lab now.

Zierler:

Yeah. And I’m curious about—so there’s the Weinberg-Salam unified theory, and then, you know, there’s the atomic parity violation experiments. What was your work in examining the relationship between the two?

Franklin:

Obviously it was an important thing because—but there was a controversy. I like controversies because you see methodology more explicitly. So there was this thing that early on in the atomic parity violation, the early experiments disagreed with Weinberg-Salam. And then the later experiments agreed with it.

And so it was an interesting thing is that how that gets resolved; how you resolve discord. I was also fortunate that at that time, one of the important experiments was being done at Colorado by Carl Wieman, atomic parity violation. I was mostly—I had more interaction with one of his postdocs.

But I was literally getting results as they came out of the computer when I was working on the history of that. And at one point, I declared that history had stopped, that I [laugh]—you know, they were of course going on with their experiment. I said, “You know, I have to stop and write something.” [laugh] So the connection with Weinberg-Salam was more for me in the problem of resolving discord. In fact, one of my books is called Selectivity and Discord: Two Problems of Experiment.

Zierler:

Would you say—is that a theme in your work? Is that a theme throughout your work, and it’s all about resolving discord?

Franklin:

No, not always, no. Sometimes I just do—I don’t do straight history. I’m always doing history—I work on the borderline, I would say, between history of science and philosophy of science. And I—my intent in doing history is always in some sense to have some kind of philosophical problem to solve.

But and sometimes there was—in the ‘90s, there was a big controversy between the social constructivists and, if you will, the hard-line rationalists like myself. Although rationalist is not the right term really; empiricist is. And I wrote a whole book called Are There Really Neutrinos?, which was essentially an argument against the constructivists with whom I have had more explicit arguments.

But the idea was saying, look, the neutrino is a particle that’s barely there. It barely interacts with anything. And yet we know enormous amounts about it. How did we find this out? And so I started with the discovery of radioactivity in 1896, and ended in 2000 or so, unfortunately just before the solar neutrino problem got solved.

The paperback came out after the SNO experiment. And I insisted to the publisher they let me include the SNO result because I said, “Otherwise I will look like an idiot.” And they said, “Well, there’s one page at the end of the chapter.” Publishers like to start chapters on the right-hand page. Don’t ask me why, but they do. And they said, “There’s a blank page at the end of the chapter on solar neutrinos and neutrino oscillations. Anything you—if you can write it in one page, you’re OK.” So I did.

But there was a controversy more—interestingly, I have more recently, a while back, wrote a paper jointly with Harry Collins, one of the leading social constructivists. We have found ways starting, oh, maybe 10, 12 years ago, maybe even longer, of using each other’s work. Not that we agree on everything, but finding value in each other’s work. And so that was—we wrote a paper on the early work of Joseph Weber on gravity waves.

Zierler:

So I have to ask, Allan, what value do you find in social constructivism as an empiricist?

Franklin:

Not much.

Zierler:

[laugh]

Franklin:

But one thing, and this is something that Dan Kennefick, another fine historian, said a long time ago that what they have is at least Harry, not all of them, concentrates on the details of scientific practice. So he has things to tell me about that. And also, Harry, although he will deny this, has, I believe, changed his mind. He’s now willing to talk more about evidence, and its important role in science. And I think evidence is almost everything.

Zierler:

So, Allan, let me ask you, this would be a good point, a philosophy in science question. When there is discord, right, doesn’t that always suggest that there’s a limitation in our understanding of how things work, right? There can’t be—is there such a thing as objective discord, that the universe has components to it that are discordant? Isn’t that always just a reflection on us?

Franklin:

It’s a reflection on the fact that science is done by human beings. Sometimes we make mistakes. In almost every case that I’ve looked at where there have been discordant results, somebody has made an error almost—this came—this is an interesting point.

In—the Fifth Force hypothesis was a modification of the law of gravity, a small modification. The first two experiments disagreed. Peter Thieberger got a positive result. Eric Adelberger and the Eöt-Wash Group got a negative result.

And ultimately the experiments kept getting done, and everybody agreed with Eöt-Wash. There was no Fifth Force. But to this day, nobody knows what went wrong with Thieberger’s result. This is—and I got taken to task for this —I included Thieberger’s experiment in my book, recent book, What Makes a Good Experiment? And I included an experiment that everybody thinks is wrong. And one of the reviewers said, “Well, why did you do that?”

Zierler:

What was the experiment?

Franklin:

Because he did everything right. He checked for confounding factors. He checked all sorts, the temperature effects, the magnetic effects. You know, several—you know, we’re not omniscient. We’re not infallible. And I don’t think we should demand perfection. You know, it can be good. I said the community was justified after 13 other experiments all agreed with the Eöt-Wash Group in saying Thieberger made a mistake, even though we don’t know what it is.

Zierler:

So is the—there is a quest in physics to resolve all discordant ideas, right?

Franklin:

Yeah.

Zierler:

And is that—is it fair to say that that quest is to find the Grand Unified Theory or the theory of everything? Is that the ultimate end point?

Franklin:

I don’t—yeah, I think that’s the goal of science maybe. But I think, you know, it’s a goal like traveling to the stars where we may get something that unifies the four forces. Will that end science? No. There will still be things to explore, things—how do we apply this theory? I mean, one of the problems one has now with string theory is we cannot test it.

Zierler:

Why not? Why can’t we test it?

Franklin:

There are no—nobody has calculated any empirical consequence of string theory that could be testable at the moment.

Zierler:

When you say “at the moment”, does that suggest that it is theoretically testable?

Franklin:

I think as I talk to my string theory colleagues, it’s their goal to make it testable, and they want to test it. They’re empiricists too. I mean, there’s a book recently of string theory and philosophy of science by Richard Dawid, who argues for non-empirical support. And no string theorist I know really buys into that, the idea of non-empirical support. Yeah, I mean, but remember that it’s not necessarily the end point. It may be the journey that’s the good part.

Zierler:

Sure. Can you talk about the Duhem-Quine problem?

Franklin:

Yes.

Zierler:

Where did that come from, and what is your involvement in that?

Franklin:

Well, I wrote some papers on it, or at least a paper on it, and I’ve included discussions of it in some other works. Duhem and Quine in different ways pointed out that you can always save a theory or a hypothesis from refutation by making suitable adjustments in your knowledge base. If you’re willing to give up things, then you can save any hypothesis.

And the question is, you know, that there are alternatives. And the thing is sometimes, you have to give up too much. Like, I remem…in one of the things, there was a quote from Prentki that to save CP violation, you needed to give up things like the principle of superposition in quantum mechanics. You would have to essentially throw out quantum mechanics to save something. That’s too big a price to pay—

Zierler:

[laugh] Right.

Franklin:

—to save a hypothesis. You know, it’s like, well, you know, if you pull on this string, it will break. Oh, it doesn’t break. OK, well, it’s a superstring, and then you have—it’s like a little kid sometimes.

My view of it has been that the Duhem-Quine problem as a logical problem is insoluble. You could always invent things. But you never have an infinite number of alternatives on offer. You always have a finite number, and that they usual…they will get tested. In the case of CP violation, there were 9 or 10 alternatives offered, some, you know, saying it wasn’t, you know—that you saw a K-long going to two pions. And so there were some theorists that said, “Well, it wasn’t a K-long or it wasn’t a pion. Or these were pions with spin 1 rather than spin 0.”

My favorite one was, “It’s a shadow K-long. There’s a shadow universe, and you’re not seeing the K-long from our universe. It’s the K-long from the shadow universe, which interacts with our own universe only through the weak interaction.” OK, a bizarre theory. Let’s test it. And it was tested, and it was found to be incorrect. So, you know, I think the Duhem-Quine problem is solved pragmatically.

Zierler:

And what does that mean “pragmatically”? I mean, what other options are there?

Franklin:

Well, you could say it’s insoluble, and so we can never make a decision. But that’s ultimate skepticism saying we can never know anything. That in my mind is crazy because we do know things.

Zierler:

Sure. [laugh]

Franklin:

If we flip a light switch, it’s not incantations to Maxwell—

Zierler:

[laugh]

Franklin:

—it’s electricity and magnetism that give us light.

Zierler:

And I’m curious, Allan, how did you develop an interest in the theory of weak interactions? Where did that come from?

Franklin:

Oh, I think I worked on it in my own experimental work at the Princeton-Penn Accelerator, we did weak interaction physics, K-meson decay.

Zierler:

But I’m asking did you think about like—I don’t know what the right word is. There’s a duality to it, right? There’s the day-to-day where you’re working on weak interactions, and then there’s the removed thoughtfulness of thinking about the larger context and the implication of weak interactions. So that’s what I’m asking in terms of that more removed analysis.

Franklin:

Well, what got me interested in looking at it, well, there were a couple of things. Parity violation was a big thing, made a [laugh] big impression on me. I was an undergraduate at Columbia when it was announced.

Zierler:

Right. [laugh]

Franklin:

They stopped classes.

Zierler:

[laugh]

Franklin:

They stopped physics classes to announce the experimental results. That always had a big effect on me. And also, when I learned more and started working in history and philosophy, there was a problem. When the V-A theory was proposed, there were three experiments that disagreed with it. And I was interested in why did they do that. Why did they propose a theory that was known to be refuted?

And so then I had to—then I went into—I had to do the history of how did we get to V-A, that there were good reasons for believing V-A, so there were reasons for questioning the experimental results. And they all turned out to be wrong, which was suggested interestingly by the theorists, Feynman and Gell-Mann and Marshak and Sudarshan. So, you know, it was an interesting historical question and philosophical—why do you propose a theory that’s known to be refuted?

Zierler:

Yeah. So what’s the answer?

Franklin:

Well, the answer is that there’s other evidence. It’s not just those three. I mean, Duhem-Quine says you can’t refute. But in my view is like why did we not believe faster-than-light neutrinos? Because we have all this evidence for special relativity that’s piled up over 100 years, and there’s this one thing that seems to differ. Well, when you have a disagreement between theory and experiment, theory could be wrong, experiment could be wrong, or they both could be wrong.

Zierler:

Sure. [laugh]

Franklin:

And they can’t both be right. And so in this case, it turned out of course that the experimental results were incorrect. But no—everybody thought there would be something wrong with it because we had all this—you know, special relativity is enormously supported by evidence. So nobody really worried about it.

And in the case of V-A, there were lots of things that V-A had going for it. And so people said, “Well, maybe we ought to redo those experiments.” Now that leads you to my current work, or my most recent work, is do experiments need to be replicated?

Zierler:

Now, are you—what are you referring to? The Mendel-Fisher controversy?

Franklin:

Oh, no, that’s easy. Mendel was right.

Zierler:

[laugh] Well, I’ll come back to that. But what’s your more recent work that you’re referencing?

Franklin:

Oh, I have a book called Is It the ‘Same’ Result: Replication in Physics. And then one I did with my friend Ron Laymon called Measuring Nothing Repeatedly: Null Experiments in Physics. And then a new project which we’re currently working on is called Once Can Be Enough, Jacqueline Susann was Wrong. We’ll never get that as the title.

Zierler:

[laugh]

Franklin:

They’ll never let us use it. You know who Jacqueline Susann is?

Zierler:

I know the name. I’ve heard the name.

Franklin:

Well, she wrote a book called Once Is Not Enough. And you know the implication of what it is?

Zierler:

Sure.

Franklin:

But it turns out that it was a time reference not a frequency reference, as in “I loved you once” as in previously—so no editor is ever going to let us use that title.

Zierler:

[laugh]

Franklin:

But there are experiments, single experiments that essentially determine something. Mendel is one. Mendel is one of our cases. There’s an experiment in genetics called the Meselson-Stahl experiment on DNA replication back in the ‘50s. And then there’s the discovery of the positron, a single picture. Discovery of the omega minus hyperon is another one. And so we’re working on that.

Zierler:

So, Allan, I want to ask you sort of more broadly, I mean, you used the term “social constructivism”, and I wonder what your understanding is of that line of thinking within the larger concept of postmodernism?

Franklin:

That’s—you see, my understanding of social constructivism, which is a class of science studies, is the idea that evidence does not—their view is evidence does not play the crucial role in the construction of science. And of course science is a social construct, I mean, in the sense that it’s done by human beings. It’s done by communities.

Now, I wouldn’t, in my own view, comment on the broader issue of postmodernism. But, for example, Stanley Fish, who’s one of the gurus of postmodernism, once said, “The laws of physics are the same as the laws of baseball.” And that’s nonsense. As I said somewhere in my writings, Professor Fish is wrong.

Zierler:

[laugh]

Franklin:

The laws of baseball are decided on by the owners. They decide what the laws are. There can be a designated hitter in the American League but not in the National League.

Zierler:

Oh, I see, he meant the rules of baseball, because I was going to say the laws of baseball are governed by the laws of physics.

Franklin:

No, no, he’s talking about the rules, yeah.

Zierler:

[laugh] OK.

Franklin:

But he used the term “laws”. And I pointed out to him that there was a distinction that the law of gravity would not—suppose the American Physical Society voted to repeal the law of gravity, and the French decided to keep it. Objects would not fall differently—

Zierler:

[laugh]

Franklin:

—in the US and France.

Zierler:

[laugh]

Franklin:

You know, the idea that things are just determined, that all interpretations are right, you know, that everybody—you know, I—in discussions I always like to quote Senator Daniel Moynihan: “Everybody’s entitled to their own opinion. No one is entitled to their own fact.”

Zierler:

Right. Well, that used to be true up until the current administration, so.

Franklin:

That we try not—for those of us who are, as you are, safe at home, the news about COVID-19 or the coronavirus, it’s addictive but you get depressesd.

Zierler:

So, Allan, I want to flesh this out a little bit in terms of where you see yourself situated among these broader debates about, you know, empiricism versus social constructivism. Are your intellectual, you know, opponents or sparring partners, or whatever you want to call them, are any of them represented within the field of science itself, or are you mostly sparring with philosophers and historians and people on the social science side of things?

Franklin:

My view is that, as near as I can tell, dealing with the science studies community, the sociologists, the philosophers, the historians of science, that I don’t know any scientists who are constructivists.

Zierler:

I mean, by definition, I don’t really know how you could be, right? But so that begs the follow-on question, right? If it’s not fellow scientists that you’re sparring with, so to speak, why do you care, right? What does it matter what a professor of philosophy might say about physics? Why is this worth your time to refute arguments where you’re not operating in the same intellectual sphere?

Franklin:

OK. Well, two things. First, the constructivsts teach our students when they take other courses. Our students should take such courses. They should take literature. They should take philosophy. They should take history. I’m a strong believer in liberal education. But I think there are limits to what I’m willing [laugh] to say. And so in part, but also as—these people have influence in all sorts of places.

And I think one—those of us who are, if you will, in the empiricist tradition, need to know what they’re saying, and, two, need to combat it, because it’s just wrong. And so—and also, as anybody will tell you from my previous work —yes, I like arguments.

Zierler:

[laugh]

Franklin:

So [laugh] but also my work is fun for me, you know. Just the—as I always talk about it, you know, the process is almost more fun than the final product. That working on something is—it’s nice to have the book to hold in your hand.

Zierler:

So I wonder, I mean, just looking back on my own—I was an undergraduate in the late 1990s, and I recall specifically that social constructivism was a big deal in those days. You know, the French philosophers like Derrida, and people like that, that was a big deal. So I wonder, you know, in terms of your long career, you know, within these debates, where you see the ebb and flow in terms of, you know, when empiricism seemed to be sort of more popular, when social constructivism—and if you could think broadly from the beginning of when you started to be involved in this right up to the present day.

Franklin:

Well, I think there was a period I think in the ‘80s and ‘90s when social constructivism, postmodernism, at least in science studies, was big. I think, maybe incorrectly, that the empiricists have won in that debate. Maybe not in literary studies and such, but certainly within science studies, I think—but I have—because I’m in a physics department, I don’t really have a lot of connections to the historians.

We don’t have many—in fact, I don’t know if we have any historians of science here at Colorado. We have some philosophers of science, but they tend to be in the empiricist tradition. But I think on that, we—the empiricists have won.

I mean, the—what do you make of the statement of Derrida that “the Einsteinian constant is not a constant but the essence of the game,” a famous quote that we love? I once went to a conference done by a couple of people in language where they were in favor—and this is a long time ago.

And I raised the question that says, “Well,”—somebody responded, “Well, you have to understand the context.” And I said, “Well, in what context can that be true? You know, the Einsteinian constant”—I assumed they’re referring to the speed of light—“is a constant.” So but I don’t know what the literary people are doing now. The stuff I read tends to be on the side that I’m on.

Zierler:

Now, another question that sort of is on the—it’s somewhat related. And that is, you know, the role of other issues and their impact on physics, things that have social implications like diversity in physics, and women in physics, and underrepresented groups in physics, do you spend time thinking about those issues as well in terms of philosophy of physics?

Franklin:

Not a lot. I think about it more in terms of the functioning of my own department. Do we—should we have more women? Yes. But then again, you know, there are—I don’t know what the pipeline looks like. If you don’t have a large number of women PhDs—and it’s odd because the numbers don’t seem to have changed. We’ve had 20%, give or take—and I hear that it’s gone down a little—of women graduate students in physics. This is not true in other areas.

Biology for example has more than half the grad students are women. But do we need more diversity? Yeah. And I don’t think it necessarily—will improve physics. It should be a level playing field. It should be everyone getting a chance, equal, if you will, opportunity. And that doesn’t seem to be true yet.

Zierler:

I want to ask you if you can reflect broadly on—you’ve had a lot of visiting professorships at centers that emphasize, you know, history and philosophy and things like that. And, you know, I wonder what—in what ways those experiences influenced your thinking and, you know, provided you an opportunity to concentrate in these matters in an environment that, you know, very closely aligned to the kinds of issues you think about?

Franklin:

Oh, enormous. I mean, one of the formative experiences was my visits to the department of history and philosophy and science at Chelsea College, later King’s College, in London. I was in a physics department doing history and philosophy, and was kind of regarded as somewhat of an outsider. I went to that department, and it turns out that was a department where the head of the department was a former physicist. There was another former physicist. They were essentially like me but further along.

And the seminars there, I learned an enormous amount, the philosophy of science, in the Chelsea seminars. And also we always—the Chelsea seminars were on Thursday. The London School of Economics philosophy seminars were on Tuesday, and we always went to LSE. And there I got to meet my friend and colleague, co-author, Colin Howson, from whom I learned my Bayesian approach to the philosophy of science. Colin unfortunately passed away earlier this year.

Going to good places has been, you know, enormously helpful, given that I have no formal [laugh] training to speak of. So, you know, and the seminars at Chelsea were odd, to say the least. Heinz Post, the director would always say—the speaker would like a straight run, i.e., no questions in the middle, no interruptions. And the speaker would start, and about an average of say seven minutes, Heinz could no longer restrain himself, and would ask a question, and then everything was on.

The speaker—the seminars would typically last two hours, and if the speaker got to speak for an hour, they were lucky. And so it was a real discussion group, and there were a lot of very smart guys there. [laugh] And so I learned an enormous amount. And similarly at LSE, although LSE was more dignified, if you will, more decorous. But they too…

Zierler:

So, Allan, I wonder if you can talk about—I mean, you have—you occupy this very unique role in the field, right, that you are, of course, a real high-energy physicist, and you have, you know, a solid grounding in all of these issues. But then you have, I don’t know what the right term is, extracurricular activit…interests or, you know, an additional expertise. I wonder if this emphasis and interest on philosophical and historical matters has influenced sort of the kinds of graduate students that you’ve taken on, or the courses that you’ve taught over the course of your career?

Franklin:

Oh, I’ve had only a few graduate students who worked with me on history and philosophy of science. There was Bill McKinney at Indiana, and Tom Weissert at Colorado. I did have one student in high-energy physics back in the old days, back in late ‘60s, early ‘70s.

But it certainly has influenced my teaching. I—back in—I think it was probably in the early ‘80s, I instituted a course on the history and philosophy of physics in the physics department, which is now cross-listed with philosophy. And they let me do essentially what I wanted. And so the course has evolved as my work has evolved. [laugh]

It was very interesting that when I first started, my worst students were the physics majors because they thought it was just going to be all discussion. We don’t have to do anything. There’s not a—there’s no—nothing to dig your teeth into. But as things have gone on, and word of mouth has changed, the physics majors have become a lot better—became a lot better.

Zierler:

How so? How have they become better?

Franklin:

Because they now take it seriously.

Zierler:

[laugh]

Franklin:

It’s not—to use a word—it’s not BS. But there’s the discipline, and that there are problems, and that there are issues that you need to think about. And so that’s what changed, and they then take it seriously.

And 85—roughly 80% to 85% of my students in that course—oh, I’ve taught that—I taught that course for like 30 years, on and off. And the department encouraged that. And they think it is a course of value to the physics majors. And so 80% to 85% of students in that course were physics majors. The philosophy majors don’t come over [laugh] much.

Zierler:

Right. Well, I wonder if that—how—what level of physics knowledge are you assuming the students have for a class like that?

Franklin:

Oh, it’s an upper division and also a graduate course. And so they’re typically seniors. And so they have a substantial physics background. The philosophers not so much. But there are lots of issues you can deal with without technical knowledge of physics.

You can re…you know, if you’d noticed in my books, there were very few equations. So you can understand the story without necessarily being able to do calculations in the field. And so I think the course has been of value, even to the physics majors. But it’s I think—it’s something that I think people recognize.

I don’t know if I’m so unique. There are other people who have goo…Peter Galison at Harvard has a PhD; Roger Stuewer, who’s retired, at Minnesota. And there are people who know—have enormous amounts of technical physics knowledge. I mean, John Norton at Pittsburgh knows way more relativity than I do.

Michel Janssen certainly at Minnesota knows more history of quantum mechanics and relativity. Dan Kennefick, the great expert on GR, both theory and experiment. So, you know, there were a few of us around. We could use more.

Zierler:

Maybe it’s a difficult question because it requires some self-analysis, but would you say that your interest in philosophy and history has influenced the kinds of—the ways that you’ve conducted research as a physicist?

Franklin:

No.

Zierler:

You try to keep those worlds separate?

Franklin:

I haven’t done physics research since the mid-’70s. And where it influenced me is the kinds of things like Gene Commins, you know, you got to take good data. You know, I was pretty good at looking at data, which is what I have spent my career doing, looking—essentially looking at data, which drives me nuts now—

Zierler:

[laugh]

Franklin:

—because I can’t get any good data. And [laugh] you know, I look at, you know graphs of deaths or cases, and you don’t know about under-reporting. But you don’t know how they’re being under-reported. I was never a group leader in physics.

I was always part of someone else’s group, and so I didn’t have to make decisions as to what we do next. And there I think you need some knowledge, judgment, taste as to what’s the most important thing to do. And that might very well involve philosophical considerations.

Zierler:

So I’m curious, you know, this transition that you mentioned in the mid-1970s when you stopped doing, you know, the hard physics research, was that a gradual process for you? Did you wake up one day and say, “Wait a minute, I’m going to change this whole situation”? How did that go about?

Franklin:

No, it happened gradually. I don’t know if you looked at my CV.

Zierler:

Yeah.

Franklin:

But I did a couple of papers on literature and thermodynamics. I had Thomas Pynchon’s Classic Presentation of the Second Law of Thermodynamics, an analysis of the Crying of Lot 49. And I did two papers on Jorge Luis Borges and thermodynamics. If I talk to my friends in the humanities, the English department, they don’t care that I’ve written 14 books on history and philosophy and physics.

They do care about—they think it’s really amazing that I once had dinner with Borges, which I did. It was interesting. But, no, I—so I did—I didn’t want to do high-energy physics anymore. It was just getting too hard in different ways, and it was unsatisfying.

Zierler:

Was it also that—Allan, was it also in high-energy physics that the field was reaching a point of maturity where some of the biggest questions had already been resolved? Is that part of it as well?

Franklin:

No. It was more that the groups were getting larger, and this is when they got to be 10 physicists, you know. And I couldn’t see my own contribution as easily, you know, that I was part of a group more than I was when I was, say, a graduate student or even at PPA. And that was part of it.

And if I were to be completely honest, I wasn’t as good at it as I wanted. So then also there was a lot of travel from Colorado. One year, I counted up that I spent three months at Stanford at the Linac at SLAC. But it wasn’t three months in three months, it was three months in four-day stretches. And the person who loved me most was my travel agent.

Zierler:

[laugh] Right.

Franklin:

This is the days when you had a travel agent.

Zierler:

[laugh] Right.

Franklin:

And so I started to find things essentially to keep busy that would be of interest. And I started with the science and literature, and then I had taught a course with Howard Smokler, a friend from philosophy on Galileo and Oppenheimer. And if you want to talk about Galileo, you have to talk about—you have to learn about Copernicus. In order to learn about Copernicus, you got to learn a little bit about Greek science.

So I started learning that stuff. And my first work in the history of science was on medieval science, the Principle of Inertia in the Middle Ages. There again I was fortunate. Joan Cadden, who’s become a very distinguished historian of medieval science, was visiting here as an instructor. And she had worked with Ed Grant and she—we were friends, and she put me in touch with Ed, who learned I was going to teach medieval science at the City University.

I got a job. I wanted to be there for personal reasons. And he sent me all sorts of stuff, and I got this idea, you know, with no training, no nothing. I just did it. The philosophy of science I had an interest in because I took some courses in it. But it wasn’t until I got better training informally, like at Chelsea, that I started doing the more philosophical stuff, and knowing more about it.

Zierler:

And I’m reminded at this point with a comment you made earlier in our discussion. You emphasized that in high school, you were strong across the board, right? So I wonder if, you know, the arts side of the arts and sciences was sort of a latent talent that was always there but was sort of pushed to the sidelines during your graduate and early career?

Franklin:

I don’t know. I never thought of myself as a writer or anything. I think—

Zierler:

Well, I would think your list of book publications might suggest otherwise. [laugh]

Franklin:

Yeah, but—well, it’s very interesting. When I was preparing for the interview—I actually prepared a little—I wanted to see what kind of questions would be asked, so I went and looked in the AIP list. And I was looking for historians of science, and the only one I found was Gerry Holton.

But I was looking in the answers for Roger Stuewer, because I thought he might be in. And when I went over the answers, there was Brian Schwartz, who went to high school with me. He was interviewed, he’s in the archive, and he mentions me twice. [laugh]

Zierler:

[laugh] Yeah.

Franklin:

And one thing he does mention is that I was strong across the board.

Zierler:

Yeah.

Franklin:

But it was—I always—it was almost accidental to go into the history and philosophy. It was something I liked.

Zierler:

Was it ever a hard sell with your department in terms of—you know, was there an expectation? You know, you’re here to do physics research. What’s this history business? Or was that—were you able to manage that pretty well?

Franklin:

It was difficult for a while, that it was not the kind of research they hired me to do.

Zierler:

Right. So what was the case that you made? How did you defend these new interests?

Franklin:

Well, one, I seemed to be doing it reasonably well. He’s publishing books. And I was very fortunate that starting it must be around 1990 or late ‘80s, there were three chairs of my department, John Cumalat, Bill O’Sullivan, and Paul Beale, all of whom were very supportive. And if your chair is supportive in an academic environment—

Zierler:

Life is good.

Franklin:

It didn’t hurt that my work was reasonably regarded. There were times when it was hard. But I was a grown-up. I knew that it was not going to be received favorably by everyone.

Zierler:

Yeah. And so that leads me to my next question, which is, you know, earlier, you emphasized one of the reasons why it’s important to, you know, take on social constructivists, even though they might not know the sciences, because they have an influence in the public sphere, right?

Franklin:

Yes.

Zierler:

But you emphasized in terms of the audience that they’re teaching students as well. And so my question is to what extent were you motivated by conveying [phones rings] empirical science concepts to not just students but the broader reading public?

Franklin:

I tried that once. I wrote a book called No Easy Answers: Science and the Pursuit of Knowledge, which was not a great success. It was OK critically, but I’m too much of a data freak.

Zierler:

[laugh]

Franklin:

Too many graphs, too many figures. It didn’t do anywhere close to the kind of—like Harry Collins and Trevor Pinch’s The Golem, which must’ve sold 30 times more than I did. And their book actually was part of my motivation for not so much writing that one but for writing Are There Really Neutrinos?, which didn’t go to the same audience.

They did sell books—they weren’t in supermarkets but they were selling [laugh]—and Harry’s a good guy. He’s a friend. We still disagree intellectually. But, yeah, I think we have—and now—not that I’ve done anything explicitly, but we have now a distrust of science.

Zierler:

Yeah, and that—actually, that was my next question. And that is, you know, we’re talking now—I mean, you know, future researchers who will listen to this, we should emphasize that we are now in the middle of a massive crisis with coronavirus. And one of the layers of this crisis is the crisis of communicating scientific concepts to the broader public, right?

That seems to be at the heart of, you know, the controversy over when to reopen the economy, and how to do it, and, you know, who to trust, and willingness to take on a vaccine, and all of these things. And that fundamentally is a crisis of a disconnect between what scientists do, and how the public receives that information. And so I wonder if you’ve thought about that, and how your work might play into sort of, you know, emphasizing the importance of empiricism?

Franklin:

Well, it would be, except that I don’t think it’s particularly accessible to the people we’re talking about. I mean, it’s—I tried it, and I didn’t do it well.—

Zierler:

No, but I mean, like, I understand that point. But I’m—in terms of—I don’t know what the right concept would be—like an intellectual trickle-down effect, right, that you’re teaching and have taught a generation of students who themselves might be in positions where they can emphasize the importance of empiricism?

Franklin:

Yeah, I think that might be—and, again, many of them are going into science who are already—who are being distrusted. So that dilutes any effect. But, yeah, it’s distressing, speaking methodologically, to read the newspapers or watch CNN. I mean, it’s a disaster.

Zierler:

So let me just ask a more raw question. What is this about? Why do you think that there is this schism in our society right now? Where does it come from?

Franklin:

Oh, that’s way beyond my pay grade. I mean, I think there are real problems of people not having satisfactory careers, good jobs, feeling put upon by what they think of as the elite. You know, there are real things out there.

You know, when I was in high school, I worked in a dress warehouse. That was a different world, you know. And I think there are real grievances and inequalities in our society that we have not addressed. And that that feeds into the view of scientists as elitists. “They’re going to tell us what we should believe.” And people don’t like that.

I mean, there was a thing in the—a restaurant in Colorado Springs, which opened with no physical distancing, and explicitly as a political statement. And, you know, it was like a normal restaurant, with a line outside, a breakfast place. And they were making a statement about “You’re not going to deny me my freedom.”

And, you see, but it’s not freedom that they’re really talking about. They’re really talking about their place in society, I think, and that it’s not as good as it once was. And, again, I don’t know why. There was an American Dream that seems not to be with us now. My grandparents came over as immigrants. My parents earned enough money so I could become a scholar, but I wasn’t a real doctor, but that’s a different story. [laugh]

Zierler:

[laugh] No one’s perfect. [laugh]

Franklin:

[laugh] But there was a dream, I would have a better life than my parents did, and that was their dream. But now I’m not sure that people have that, that their kids are going to have a better life than they had.

Zierler:

So to the extent that this breakdown is a two-way street, where’s the onus on scientists to do a better job in communicating what they do, and for their part, you know, in terms of taking responsibility to make these connections where they currently are not being made?

Franklin:

We haven’t done as good a job as we should have done. I don’t know how to make it better myself. When I was chair of the Forum on the History of Physics, I did say we needed to do a better job, and tried to encourage that. But I don’t know how to do it. I mean, it would be nice to go out into the public, and give talks about science. But there aren’t that many opportunities. I am planning—I was planning this spring to teach [phone rings] can’t control the technology from the…

Zierler:

No worries.

Franklin:

But I was going to do a discussion group on the nature of science on—for something called the Osher Lifelong Learning Institute. Have you ever heard of that?

Zierler:

No.

Franklin:

It’s a thing—somebody set it up, and it’s all over the country. It’s for people over 50, and it’s people who want to stay intellectually active. And they have discussion groups. They have courses. They have—and they meet, you know, once, twice a week, whatever, eight-week sessions. And if you pay them a certain fee, you can take as many courses as you like.

And I was going to do that on the one on the nature of science this spring, which got stopped. But I told them that I would do it in the fall if necessary by Zoom. [laugh] And I was going to use a very good book, which is absolutely a lovely book called The Hunt for Vulcan by Thomas Levenson. I have the book. It’s up at school at my office, which is inaccessible at the moment—which is about a planet that was hypothesized to explain variations in the orbit of Mercury. And it’s brilliantly written for a non-technical audience.

I held an informal discussion group with some friends here, and they loved the book. They could understand it. And I think that’s maybe one of the things we could do. I mean, there are people who wish to maintain an interest in stuff, and I think this is an idea. I have friends who have done it, who have taught courses, or led discussions, and they find it very satisfying, and they found the students liked it. Now, these are 50-year-olds. But then again, 50-year-olds have influence.

Zierler:

Right. [laugh]

Franklin:

So they have money too. [laugh] And so I think this is something—this is a kind of, if you will, public service. I think we need to do more of it. I don’t know what all the alternatives are. It’s interesting that at least now, at least if you watch CNN, there’s Sanjay Gupta, and Dr. Fauci. You know, these are guys who are actually highly regarded. They have higher approval ratings than the rest of the administration.

Zierler:

Right. Well—

Franklin:

But—

Zierler:

Yeah, please, go ahead.

Franklin:

You know, the trouble is the administration has no—it doesn’t deal with evidence at all. I mean, here you have people who are getting tested every day, and they still come down with it. The people don’t seem to say, “Well, maybe we should do more of this.” But…

Zierler:

So, Allan, I think my two final questions—I want to ask a question that’s broadly retrospective, and then one that’s sort of forward-thinking, future-oriented. So the first question is, is there a single concept that you feel serves as a narrative through-line in all of your work on physics and philosophical questions? Is there an overarching concept or theme that connects all of this work, or a motivation that serves as a sort of centerpiece of all the work that you’ve been engaged in over these past four decades?

Franklin:

Yeah. I would say that it’s the fundamental basis of Bayesian confirmation theory.

Zierler:

So first let’s define what is Bayesian confirmation theory?

Franklin:

Use of the probabilities in talking about beliefs. OK. But what converted me to it was the idea that if you observe evidence that’s predicted by your hypothesis, you should strengthen your belief in it. And if it doesn’t, you should weaken your belief. That’s the—essentially what I’ve been doing for 40 years.

There’s a marvelous book called the The Art of Probable Inference by Richard Cox. He was actually a physicist. I’ve written a lot about his work, and I’m doing it now for our new book, Once is Enough.

He talked about the witches in Macbeth. And Macbeth is riding along, and the witches say, “You know, you will be Thane of Cawdor, you know, Thane of Glamis, Thane of Cawdor, and King thereafter.” And he says, “Well, Thane of Cawdor.” And he rides along, and he gets this message that says the Thane of Cawdor has died, and so he’s now that.

And then there’s—so he’s starting to say, “Well, these are are unlikely hypotheses. But then again, they keep happening to be true, you know, I get evidence. Maybe these witches know something.” You start believing the witches because the evidence—so I think that’s the theme is that evidence is important.

But the other thing is that evidence has to be reliable, that you have to have good reasons to believe that evidence. I think the epistemology of experiment, which I’ve talked about ad nauseam, is probably my most important contribution to the philosophy of science. So those are the things. Evidence is important, and you have to have good reasons to believe it. That’s the—what I spent, yeah, 40 years doing.

Zierler:

Right. Well, for my last question, Allan, I want to ask, you know, maybe in light of what’s going on now or sort of even generally, more generally, what do you think in the future are going to be the most interesting questions at the intersection of physics and philosophy? What are things in terms of, you know, issues that remain to be discovered in physics, and how that might impact philosophical thinking, or new ways of thinking about philosophy, and how that might influence the kinds of, you know, programs and research endeavors that are going to be undertaken in physics?

Franklin:

Well, I think, from my point of view, one of the things will be [??] string theory, a theory of everything, because that’s going to pose some very interesting philosophical problems. It’s also going to open up God knows how much good research—

Zierler:

[laugh]

Franklin:

—in science and physics.

Zierler:

So let’s take first the philosophical problems. Let’s say string theory is going to be testable, right, and it is tested. What then? What’s—you open the Pandora’s box. What are the philosophical problems that immediately and inescapably will have to be posed?

Franklin:

Oh, it’s just going to be the normal questions of, well, how good is the evidence? What does the evidence imply? Does it apply? Does—once question but I think, well, if it’s a theory of everything, and you confirm it here, does it work there? You know, how do you extrapolate? Extrapolation is, as somebody said, notoriously difficult. And so I think those are going to be interesting questions.

And then some of the interesting questions that Richard Dawid raised is can you talk about non-empirical support? I think in the absence of any empirical support, it becomes, you know, wishful thinking. But I think those—and—but the trouble is that predicting the future of science is notoriously unreliable. [laugh]

Zierler:

Right. [laugh]

Franklin:

It has never worked. And so to try to say what will be the philosophical questions raised by the new science is even more unreliable.

Zierler:

Well, perhaps a more constrained way of asking the same question is what are the kinds of projects that you want to take on in the future? What are the issues that you’ll be thinking about?

Franklin:

To be honest, I haven’t thought about—and this has been true for me generally. I don’t think about a new project until I finish the last one.

Zierler:

Uh-huh. [laugh]

Franklin:

But then again, things will pop up. I mean, for example, I now have 2.7 books on the replication crisis. Now, I never thought there was going to be a replication crisis. The idea that experiments in psychology are not replicable never occurred to—well, I never looked at it.

But and so, you know, I now have two concise books, and working on a third, which is now getting less concise [laugh] but with my friend Ron Laymon. And so I think it’s hard to know. But then again, the question—in philosophy of science, the questions of evidence and its relation to theory have been things that have been essentially constant over centuries, really.

You know, there were good empirical philosophers way back. [laugh] So I think—but I do think you’ve hit on this thing about what can we do to explain and persuade people of the virtues of science, to tell them what science is, and what it isn’t, and what its limitations are, and such? And I don’t really know how to do that myself.

But then again, people have been trying. You know, my late colleague, who we overlapped for one year, George Gamow, managed to make science accessible. He had all these books. I remember reading them in high school, The Birth and Death of the Sun; One Two Three ... Infinity. He managed, and he was a great physicist too.

And but I don’t know. I think things are actually harder now to do that, in part because of the divisiveness of American society. I don’t know what it’s like elsewhere, but I suspect there are similar things. But, yeah, we do need to do a better job of explaining, you know. It’s just too—sometimes I think it’s, you know, too hard. The only good thing about staying at home is I get to ride my bike more—

Zierler:

[laugh]

Franklin:

—because I don’t go to the office.

Zierler:

Right.

Franklin:

And that poses some problems because I have some things which are at the office, which I can’t access from home.

Zierler:

Well, I know what a delight it is to ride a bike in Boulder, so I’m glad you’re keeping busy with that.

Franklin:

Oh, yeah, well, I’m an e-bike now.

Zierler:

[laugh] That’s all right. That’s all right.

Franklin:

But so far this calendar year, I’ve ridden over 1,000 miles.

Zierler:

[laugh] That’s good. Well, Allan, it’s been an absolute pleasure talking with you today. I really want to thank you for your time.

Franklin:

It’s been a pleasure, and it really is an honor. Have you gotten Peter and Michel?

Zierler:

Well, let me—I’m going to cut the interview here.