Edmund Bertschinger

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ORAL HISTORIES

Credit: Chantal Acacio

Interviewed by
David Zierler
Interview date
Location
Remote Interview
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Interview of Edmund Bertschinger by David Zierler on August 4, 2020,Niels Bohr Library & Archives, American Institute of Physics,College Park, MD USA,www.aip.org/history-programs/niels-bohr-library/oral-histories/45453

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In this interview, David Zierler, Oral Historian for AIP, interviews Edmund Bertschinger, professor of physics at MIT. Bertschinger recounts his childhood in California and he describes how his natural curiosities developed into academic talents in math and science. He describes his undergraduate work at Caltech where he became interested in radio astronomy. Bertschinger describes his decision to pursue a Ph.D. under the direction of Arno Penzias at Princeton, and he explains the formative influence of Steve Weinberg’s book The First Three Minutes. He describes how he came to work with Jerry Ostriker on galaxy formation. Bertschinger describes some of the administrative decisions that defined where cosmology and astrophysics were studied at Princeton. He explains how he developed his interest in social issues including nuclear disarmament, and why he initially pursued a career at the State Department. Bertschinger discusses his postdoctoral work at the University of Virginia with Roger Chevalier and his next postdoctoral position at Berkeley where he worked with Chris McKee. He explains the importance of charge-coupled device detectors as a key technology advance for astronomy, and he describes the circumstances leading to his decision to join the faculty at MIT. Bertschinger recounts how his social interests had became increasingly focused on gender issues and how, in his view, the toxic masculinity that pervaded cosmology pushed him further and further from the field. He describes his ongoing interest in nuclear and social issues, and at the end of the interview, Bertschinger explains that he has been fortunate to have been able to shift his current research interests while remaining within the physics department. 

Transcript

Zierler:

OK, this is David Zierler, oral historian for the American Institute of Physics. It is August 4th, 2020. It's my great pleasure to be here with Professor Edmund W. Bertschinger. Ed, thank you so much for joining me today.

Bertschinger:

My pleasure. Thank you, David.

Zierler:

OK, so to start, would you tell me your title and institutional affiliation?

Bertschinger:

I'm Professor of physics at MIT. I'm also an affiliated faculty member in the program in Women's and Gender Studies there.

Zierler:

And when did you begin your affiliation with the Women’s and Gender Studies Program?

Bertschinger:

In 2018, I believe. That's when I received a secondary appointment in that area. It's a program within the School of Humanities, Arts and Social Sciences.

Zierler:

Does it go back before 2018?

Bertschinger:

Not in a formal way, however, I have been a friend of Women’s and Gender Studies at MIT. for a number of years prior.

Zierler:

OK, well, we'll come back to that later in the interview. But for now, let's take it all the way back to the beginning. Ed, tell me first a little bit about your parents and where they are from.

Bertschinger:

Both my parents are deceased now. My father was born in Chino, California, in southern California. He originated from immigrants from Switzerland and Germany. My great grandfather immigrated from Zurich in the late 1800s and established a contracting business in the farming region of Southern California. There was lots of need for constructing farms and supporting operations, and that was the family business.

My father then began college at UC Berkeley, although he never finished college, and while there he met my mother. My mother was a recent immigrant in the 1950s from Finland. And in contrast with my father, my mother had no education beyond eighth grade. She came to the US speaking no English, and she basically came with some friends to start a new life after Finland was undergoing hard times following the Second World War.

Zierler:

Now, when you say friends - no family, she came with no family?

Bertschinger:

She came as an adult with no family, although she did have some relatives in the US. She had an aunt who sponsored her and who arranged for her initial housing and first job and ultimately her learning the language. My mother also came from a farming background.

Zierler:

What degrees did your parents pursue when they met in college?

Bertschinger:

My parents did not meet in college. My father had dropped out of college. He received no college degree and mother had not even completed secondary education.

Zierler:

I'm sorry, I misunderstood that. So where did they meet?

Bertschinger:

They met, I believe, at a dance hall in Berkeley, California.

Zierler:

Is your sense that both of your parents had they had more promising opportunities, would have pursued higher education to its completion?

Bertschinger:

No, they were simple people. Education was not part of their family traditions, at least not higher education. They were working class, in fact, lower working-class people for whom higher education was not a serious consideration.

Zierler:

But I imagine, though, that they viewed education as parents differently than for themselves. They probably emphasized the importance of education to you.

Bertschinger:

My mother did, certainly, as an immigrant who had to learn the language and customs of a new country. She realized the importance of education. And she did stress that to me. My father was, I would say, at best, indifferent and at times even critical of my desire to pursue a career in higher education.

Zierler:

What were their professions?

Bertschinger:

Well, my mother was a housewife. My father sought to become a draftsman. He was working in the early years of my childhood for the city of Oakland in their planning department and trying to achieve some status as a draftsman. After he became unemployed, he basically had no steady job. We moved to Southern California because his parents’ house became available after the death of his father, my grandfather. And then my father eventually learned enough electronics to start a small, self-employed television repair business at home. That was the extent of his profession.

Zierler:

Were you involved at all in that business? Did you learn how to tinker in his shop?

Bertschinger:

I did. If you had seen our dining room, I got to learn a little bit about electronics and tinker indeed. And that was a very useful interest and skill for me later on.

Zierler:

Did you realize early on that you had a skill in math and science?

Bertschinger:

I did. I was an avid learner, passionate about learning everything I could. Early, I had many of the usual childhood interests in such things as dinosaurs or FBI agents. But my life really took a turn when I checked out from the school library in the first grade, a little "Golden Atlas of the Sky” book of star charts. One evening my best friend and I were out after dinner and I looked up in the sky, looked down at my field guide then up to the stars and exclaimed in delight, "Richard, there’s Orion!" I didn't know how to pronounce the constellation, but I was phonetically sounding it out and also putting together the pattern of stars and recognizing Orion’s belt in the sky. It was an ecstatic moment for me. The idea that we could go beyond ourselves and be participants in learning about the universe just enthralled me. And that was the beginning of my interest in astronomy. And then that led to physics and mathematics.

Zierler:

Ed, when you say your father was indifferent at best to your educational pursuits, did he have expectations that you would join him in his business and by pursuing academics that would prevent you from doing so?

Bertschinger:

No, he did not. I think the nature of his feelings about education were shaped by his experiences growing up in the lower middle class and his own personal struggles with maintaining employment. There were perhaps some ways in which he felt that the system was stacked against him, but he was also a very difficult father for his children. I was the oldest of four boys. There was conflict among us boys in the family and he was often an absentee father. So it was a difficult childhood for us. And often times what motivated me was not any desire to be led by his pursuits, but rather a strong independent streak to try and achieve something better for myself.

Zierler:

And your mom must have been a much stronger source of comfort and encouragement for you.

Bertschinger:

I would say that she was, yes. Also, I want to point out one thing that was very important for me culturally growing up, my mother's Finnish heritage. Although my surname is from Switzerland, I identify primarily as Finnish American, at least as far as my nationality and ethnic background. That is although I never properly learned the Finnish language, my mother spoke Finnish with all of her friends. I was immersed in Finnish culture. I learned the morals and values of Finnish culture. And those were a big part of her influence on me to this day.

Zierler:

What might be some readily identified Finnish influences in your upbringing?

Bertschinger:

The most prominent one is a Finnish cultural trait called "sisu.” Sisu is a Finnish word, which directly translated means "guts" as in the intestines. And just like the English word guts, it refers to a kind of fierce determination and persistence in the face of adversity. Finnish sisu is a prominent cultural trait that Finns associate with themselves and maintain strong pride in. And I was taught this trait and valued it personally as a way to persist in the face of adversity.

Zierler:

Now I know what word to understand how the Finns were able to put up such a fight against the Soviets on the eve of World War II. I've always wondered about that, how they were able to do that. It must have been "sisu."

Bertschinger:

That's right. And that's one of the prominent examples that Finns cite.

Zierler:

I know you were born in Oakland; did you grow up there?

Bertschinger:

The first part of my childhood was spent in Oakland, California. As I said, I had three younger brothers. All of them were born in Oakland. However, I was the only one who went through a bit of school in Oakland, having completed the second grade.

I think my next brother, who was two years behind, had just gone to kindergarten. We then moved to Southern California, as I said, after the passing of my grandfather and lived in a very different neighborhood. But I had acquired enough of my early schooling and my values in Oakland so that culturally I'm quite different from my brothers. And that is because Oakland, California and Chino, California, in Southern California are two very, very different places. That was true in the early 1960s and it is equally true now.

Zierler:

Obviously, you experience schools at different stages of your childhood. But what was the quality of the education comparing Oakland with Southern California?

Bertschinger:

The Oakland public schools education was absolutely superb. There was a strong emphasis on academic excellence. I had diverse classmates from seemingly every racial group. Parents valued education. Even though we were in a working-class area of Oakland, education was highly valued. In Southern California where I grew up, by contrast, education—there was some value to it, but not nearly to the same extent. To desire to teach one's self more advanced mathematics, for example, than was being presented in class was extraordinary and labeled me as a misfit compared with my classmates. But, of course, somebody who was also endeared by the teachers.

Zierler:

You were very young at the time, but I wonder if the space race in the 1960s had a formative effect on you and your later interests.

Bertschinger:

Absolutely. That's an excellent historical observation. It absolutely did. I was an avid follower of the Gemini and Apollo missions. I was a little bit young at the time of the Mercury launches. And certainly the beginnings of interplanetary space exploration with the Surveyor missions to Mars and Venus, the rise of Carl Sagan as an educator and scientist involved in those missions. Those were tremendously exciting to me. I think I was, let's see, it would have been 1970, so I was eleven or twelve years old. My parents had bought me a small refracting telescope, a two-and-a-half-inch refractor.

Zierler:

Did they do this, Ed, because you asked for it specifically, or did they recognize that this would be... You said, I want this?

Bertschinger:

Yes. Yes, that's exactly right although I didn’t expect to get it because we were poor. And I received it not too long before the total eclipse of the sun over the east coast of the US in 1970. There was a partial eclipse over much of the US, including even Southern California, where I was at the time. So I projected the sun onto a card and sketched it, observed the sunspots. I was just enthralled with seeing what was up in the sky and feeling a connection with it through my passion for understanding nature.

Zierler:

Did you know by high school that you were you had standout abilities in math and science?

Bertschinger:

Oh, it was very clear. When I began third grade in Southern California, I was like an alien from another planet. I was several grade levels ahead of my classmates. I had a third-grade math teacher in Southern California who gave me algebra problems so I began to teach myself algebra because she realized that the curriculum was not really appropriate for me. So, absolutely.

I should mention one other thing about growing up in Southern California that will be important later on. We moved into my grandparents’ home, which had been built by my great grandfather after he immigrated from Switzerland. But when we moved in, the neighborhood was no longer just farmlands, it was primarily early farm workers. I lived, our family lived, in a barrio, a Chicano neighborhood, primarily Mexican American immigrants who originally moved to Southern California to work on the farms and then they built homes and settled in the area.

Although our family was working class, at that time, given my father's unemployment, we were better off than our neighbors in the area. There was a great deal of poverty. There was also gang violence, drugs, even murders in my neighborhood. It was not a safe place to grow up. And the inequities that were quite apparent every day on the streets definitely played a prominent role in shaping my thinking about justice.

Zierler:

When it was time for you to think about college, did you know you wanted to stay close at home?

Bertschinger:

In fact, I did not. As I mentioned, in primary school I was accelerated certainly in math and science and likewise in high school. By my junior year of high school, I had completed essentially the curriculum of the school and didn't want to lose a year of study so I enrolled as a special student at Harvey Mudd College, a small STEM focused college not far from where I was living already. Harvey Mudd is a Claremont College, about 10 miles from where I grew up at that time.

Zierler:

And this was a program for gifted high school students or you were thinking about entering college early?

Bertschinger:

I would suppose it was a little bit of both. It was not a program but Harvey Mudd, like some other colleges, would occasionally admit what they called special students, non-degree students, to take courses. And I petitioned, I applied, to take all the courses that I could from the regular first year, freshman curriculum. And I did. I took the regular freshman curriculum aside from humanities and social sciences classes at the same time while I was still in high school. And although my high school was not academically challenging, I was very active in music, particularly in the high school band.

And, so, I had a foot in both schools. I would commute several days a week, having obtained my driver's license by that time, to Claremont to take the classes at Harvey Mudd college and then return to do my work at the high school. When I was doing this, I aspired to go to, well, in fact, MIT. That was my dream school for college. I very much wanted to move away from the city and the neighborhood where I grew up. As I said, I felt like a misfit in that environment, and I was drawn towards the wonderful land of Massachusetts and MIT that I had read about.

Zierler:

And then, how far away was Pasadena, both culturally and geographically from where you were?

Bertschinger:

It's a little too much to say it might as well have been the moon. Because I was actually able to drive to Pasadena or, for that matter, to Los Angeles. However, culturally, it was as far away as the moon. Pasadena was a middle class, even upper middle-class area. It had places like Caltech, which were very, very different from where I grew up. I was first generation and low income. This was not my view of Caltech. The reason I went to Caltech was because I was rejected by MIT and two others of my higher ranked schools for freshman admissions. And so I went to Caltech.

Zierler:

And you knew you wanted to study physics? That was that was true from the beginning, as opposed to astronomy, for example?

Bertschinger:

Yeah, actually it was a bit of both. In those days, of course, Stephen Hawking was not writing popular books. But it was the kind of things that he later wrote about that drew me intellectually. I wanted to pursue theoretical physics or cosmology in order to close that connection that I observed as a young child between the scholarship and the universe.

Zierler:

Now, did names like Feynman or Gell-mann, did that mean anything to you as an incoming freshman? Did you understand what level of scholarship you would be encountering at Caltech?

Bertschinger:

I did, for a few reasons. One was that I was an avid reader. The Feynman Lectures are not something that most high school students would pick up, but I'll come to them in a minute. But, at an early age, I was an avid reader of George Gamow and other science popularizers like him.

Zierler:

"One, Two, Three, Infinity," right?

Bertschinger:

Exactly. "One, Two, Three, Infinity." That was utterly captivating to me in my childhood.

Zierler:

It's got to be the most important book in physics because so many people cite that book specifically as this is what captured my imagination and launched my career.

Bertschinger:

I was captured before that. But this was an accelerant. Coming to Feynman and so on. Actually, the slightly more technical books that I was reading in high school... Well, I remember reading one by an MIT experimental particle physicist, M. Stanley Livingston. He was a very well-known experimental high energy physicist who kind of played a big role in the US accelerator s following the war. Obviously, you know, Lawrence was a much bigger name in California, but there was this gentleman at MIT. And he wrote a popular book about elementary particle physics that captivated me. And so, of course, I knew a bit about theoretical work that was being done. But there was a second reason why I knew about Feynman and others. In 1975, I attended a summer program for bright high school students interested in math, physics and astronomy. It was based in Ojai, California and called the Summer Science Program; it still exists now in other locations. It was a six-week residential science program that goes far beyond most traditional science camps. Students work on a research project. Although they don't do strictly original research, they make observations of asteroids. At that time, we used an astrograph with photographic plates to record the positions of asteroids on the sky over a period of a few weeks and then calculated the orbital elements. This was an absolutely phenomenal experience. I was already deeply invested in physics and astronomy at that point, but it was just a tremendous affirmation that this is what I wanted to do for my career. And, of course, in that six-week program, we were exposed to Feynman. I don't believe that he lectured while I was in the program in 1975, but we visited JPL. We bought copies of the Feynman Lectures. We spoke passionately about those subjects. And then later I became a teaching assistant in that program, several years later, and we did host Richard Feynman a number of times. And other speakers.

Zierler:

What exposure did you have to astronomy? Did you spend time at Kellogg?

Bertschinger:

At Caltech, I majored in physics. When I arrived, my ambition exceeded my preparation.

Zierler:

[Laughs] How did that dawn on you, Ed? How did you come to realize that?

Bertschinger:

Well, I'll come to that. I wanted to major in physics, math and astronomy, but it was explained to me that's not allowed at Caltech. You have to choose one. So I chose physics and consoled myself with the thought that, well, I will take classes in astronomy and math. The idea of pursuing the math curriculum at the same time as physics and astronomy quickly fell by the wayside when I discovered that I really didn't have the preparation, or perhaps the temperament, to do proof based, rigorous mathematics, at least at that time.

Theoretical physics was challenging for me. And as I say, I was more ambitious than I was prepared. As wonderful as Harvey Mudd College was, the first-year physics and math preparation was not equivalent to Caltech's, and, against the better judgment of my Caltech adviser, I entered and was able to take immediately the sophomore level subjects. At the end of my first electromagnetism class, I received a written evaluation from the instructor. Even though I was taking a more advanced class, under Caltech rules, I was graded as an incoming freshman. And so I didn't receive a letter grade. Instead, I received a written evaluation and the summary of the evaluation was, “Ed tries very hard but should think about doing something other than theoretical physics.”

Zierler:

[Laughs] Meaning what exactly? How diplomatic a statement was that?

Bertschinger:

I think it was a misjudgment. I'll later say why, but it had a deep impact on me. After I picked myself up off the floor after a couple of days, I really, I cried a lot about it, I asked myself, well, what other interests do I have and what preparation do I have? And I quickly decided that I love astronomy and I have a little bit of electronics background from helping my father to repair television sets. So let me look around. I quickly discovered that there was a wonderful field called radio astronomy which blended electronics and astronomy. And so I went to Al Moffet, a radio astronomer. He also worked on radio galaxies and active galactic nuclei. He was the director of Caltech Owens Valley Radio Observatory. I asked him if I could work with him and he gave me the chance to do research the following summer where I worked as an observing assistant. That was a wonderful experience and it led to me continuing to do research in and study radio astronomy with the laser focused goal of using that as my avenue to get into astronomy.

Zierler:

Looking back, working in your dad's shop and doing television repair, in what ways did that experience sort of help you out in terms of your interest and ability and working with your hands?

Bertschinger:

It gave me the confidence that I could pick up elements of technology, learn them, and work with them. You're absolutely right to use the phrase "with my hands" because even though I really sought to understand the first principles, I actually got great pleasure from the experimental side of the field. Perhaps my favorite undergraduate class was the advanced lab, the junior lab at Caltech. And it was so inspirational to me that I thought if radio astronomy didn't work out, I might pursue experimental nuclear physics because I really, really enjoyed that.

Zierler:

By the time your undergraduate tenure was coming to a close and you were thinking about graduate programs, how well formulated was your identity as a physicist? In terms of thinking about questions about pursuing theory or experimentation, thinking about subfields that you wanted to concentrate on or even thinking about particular individuals that you wanted to work with in graduate school?

Bertschinger:

I would say that my physics identity was pretty well formed as an advanced undergraduate. Or, I should say my astrophysics identity, because I did not see myself becoming a physicist, certainly not a theoretical physicist, given my lackluster performance in theory classes.

I felt strongly motivated. I felt some competency in the subject of radio astronomy. While at Owens Valley, I had done some observations of my own, although I never properly analyzed or published them. I really didn't have that level of faculty guidance or support to do that. And the following summer, which was the summer before my senior year of college, I had spent working at the National Radio Astronomy Observatory in Charlottesville, Virginia, and also in Greenbank, West Virginia. This was before the Very Large Array in Socorro, New Mexico, was in active operation. So NRAO summer interns were based in Virginia and West Virginia. That was a wonderful experience for me and introduced me to people who were researching in the field.

Following that summer employment, I made a tour of colleges in the Atlantic and New England area. That was my first trip, by the way, out of California, aside from brief border crossings into Mexico or brief family trips into Oregon and Washington. It was my first extended time away from home, out-of-state. And I loved it. On the trips following my summer internship, I visited, among other places, Bell Labs in Holmdel and was met there by Arno Penzias. I was just captivated and felt I really wanted to work for Penzias. He, of course, had discovered the cosmic background radiation with Bob Wilson, and he was running the radio astronomy group at Bell Labs and occasionally was supervising doctoral theses at Princeton University. And it probably helps that not long after I returned back to Caltech to complete my senior year, Penzias won the Nobel Prize. But I have to say that there were others in the field whose research really fascinated me. After I visited UC Berkeley, I was almost persuaded that I wanted to go work with Carl Heiles, a radio astronomer at Berkeley. But in the end, it was the attraction of eventually working with Penzias that led me to Princeton.

In contrast with the checkered outcome of my undergraduate applications, I was admitted by all five of the schools to which I applied for graduate admission. MIT was not among them. And it was a bit of a surprise for me later when MIT showed interest in me as a faculty member because I just didn't see it as a place to do astronomy.

Zierler:

And I'm curious, in the late 1970s and early 1980s, if you can sort of tease out the terms, cosmology, astronomy and astrophysics. Where did you see overlap in these terms and where did you see distinctions that would inform not only the programs that were most relevant to you, but the kind of research you wanted to pursue?

Bertschinger:

I was drawn by the big questions of cosmology. What is the nature and origin of the universe? What will be its fate? The big questions that brought so many people into this subject. Those were fascinating to me. And I understood that's what cosmology was about. You know, also, by that time, Steven Weinberg's beautiful little book, The First Three Minutes, was published, I think, in 1977. And I devoured it, and really, really enjoyed that.

Zierler:

What was so fundamental about Weinberg's book for you?

Bertschinger:

I would say a combination of compelling writing style and rigor. Weinberg beautifully explained the physics without the need for enormous technical apparatus. I had enough background in physics, even nuclear physics, that I could read between the lines to some extent. After all, I had studied stellar evolution at Caltech. So, I knew about nucleosynthesis and I was able to read this with absolute awe at how he could take the complicated things that I was seeing in my technical classes and explain them to lay readers in a way that just made complete sense to me.

Zierler:

So, it was really, it was not so much that he was presenting new research, it's that he was synthesizing the field in such a compelling way that was really just inspirational, even though you were not a lay reader. It was inspirational to you just in the way that he presented the material?

Bertschinger:

Exactly right. Let's return briefly to your question about the distinction, how I understood the distinctions between astronomy, astrophysics and cosmology. So with cosmology, I have described how I viewed it. But I did not see myself as a cosmologist. That was an aspiration. And I thought perhaps I will be able to use the tools, the techniques of astronomy to learn something about cosmology. Astrophysics—I wasn't really so much aware at the time of the cultural separation between astronomy and astrophysics. I've come to understand that it has perhaps more to do with one's preparation than the actual objects or methods of study. I was, I'd say, equally comfortable with describing myself as an astronomer or an astrophysicist. I should mention, in that regard, that despite my early struggles with physics at Caltech, eventually I did better and felt more confident in my abilities to do basic physics.

Zierler:

What was what was the attraction, when you were considering all of your options, about Princeton? Was it the program? Was there a particular person you wanted to work with?

Bertschinger:

Yes, it was Arno Penzias. And Penzias, as I said, was only an affiliate of the Department of Astrophysical Sciences at Princeton. He was not a faculty member.

Zierler:

And you were aware of his work before you got there?

Bertschinger:

Completely. As I mentioned earlier, I had visited him. He had hosted me. I read his paper on the discovery of the microwave background. I was intimately familiar with Weinberg's book. And what's more, I had worked in radio astronomy, so I was also familiar with his work on interstellar molecular emission. I wanted to study molecular clouds using the facilities at Bell Labs Holmdel. I wrote a very focused research statement for my application to Princeton. Very precisely saying what I wanted to do working with Penzias. He's the reason I went to Princeton.

Zierler:

And you must have clicked with him personally as well?

Bertschinger:

During my college visit, yes, I did. But the great irony is, I never worked with Penzias after I arrived at Princeton.

Zierler:

Oh, what happened?

Bertschinger:

Three things happened. First, the admissions committee wisely noticed how focused and limited my view was, and they assigned me an initial project with a different person. Second, Bell Laboratories was undergoing some tumult in the early 1980s, and, following a decision by the federal courts, AT&T was broken up. At that time, this was 1982, Judge Green's decision, Arno Penzias stepped out of his science role. In fact, he had really already been an administrator for a few years. So, he may not have had much time to work with students at Princeton, and he did not while I was there. And, he became vice president of Bell Labs, basically in charge of overseeing the breakup of Bell Laboratories and the divestment of research laboratories, the splitting up into the Baby Bells and that whole process, the complicated process, of antitrust, the breakup of the national telephone system in the early 1980s. And then the third reason why it didn't work with Penzias was that, to my great surprise, I discovered that actually I did have some facility for theoretical physics and astrophysics, and I could do cosmology.

Zierler:

How did you go about developing your dissertation?

Bertschinger:

As I mentioned already, in my first year of graduate studies, when I arrived at Princeton, I was preassigned to work with a faculty member. Jerry Ostriker was a theoretical cosmologist and a theoretical astrophysicist more broadly. At the time, he was very interested in galaxy formation and dark matter, although the project he sent me to work on was one that did not involve dark matter. It was the evolution of ordinary matter, or what we call baryons. He was advocating for a propagating, explosion driven model of galaxy formation. He wanted me to work on this problem and to help develop a theoretical description of it, either analytically or computationally.

I worked on the computational project with a postdoc, Ethan Vishniac. And I worked independently on the analytical project. That project, the analytical project, was more challenging than any of us could solve at the time. And, so, after a semester, as was wont at Princeton, I got rotated to different research supervisors. I did a short project with Lyman Spitzer and then I did a purely experimental project with optical astronomers. But, during that time, I continued to work on the original project with Ostriker. I didn't tell him because I figured that he thought the project was over, I felt embarrassed that I hadn't solved the project, and, for myself, I wanted to see if I could solve it. So I spent well over a year, a year and a half, perhaps maybe almost two years working on that project. And, eventually, I solved it. I came up with something analytic, partially analytic, a solution to this problem. And it was really quite a nice piece of work. I wrote a paper, a solo paper on it. Having completed the draft of this paper, I knocked on Professor Ostriker's door. And this was around the time that I had completed my general exams and so would be looking about the possible PhD project. And, I said to him, do you remember that project that you gave me the first year on explosive galaxy formation? I think I've solved it. I've written a paper, and I would love your feedback on it. He was stunned.

Zierler:

Why? Why stunned?

Bertschinger:

What he said next stunned me. He said, I've also been working on that project for the last two years and I've just completed writing a paper with Ikeuchi.

Zierler:

Wow. [laughs] This was a total surprise for each of you.

Bertschinger:

Yes.

Zierler:

That's a very small world. How could that possibly have happened? What does that say about the culture there? Were people really not talking to each other that much?

Bertschinger:

I think it does say something about Ostriker and me. Both of us were pretty independent folks. And he had no reason to expect me to continue this. And, while I knew that Ikeuchi was a visitor to the department, I'd never heard them discuss this. So, I know that for my part, I felt a bit embarrassed about this, about not having completed the research project. And, so, having to discuss it would have exposed my own weakness. And so perhaps that's why I didn't discuss it. But anyway, what Ostriker said next was very powerful. He said, and this is to the best of my memory, “I'll read your paper, then let's discuss it.” When we met again, he said the work was correct, both our papers should be published and he would pay my page charges. Then he said,” Would you like to consider doing a Ph.D. thesis with me?”

Zierler:

Wow, wow. So, immediately, it was an opportunity for collaboration. There was no competition. There was no issue about scooping anybody or anything like that. It was just sort of you jumped on board, essentially.

Bertschinger:

Yes. And he provided some really outstanding things to me. He knew that I had some ideas for a thesis, but he wanted to see them set down on paper and to have a sensible plan. At that time, Princeton was aiming for its Ph.D. students to finish in four years. And this was, oh, probably the beginning of the third year. So, I definitely required some planning. And I was also ambitious. I still was too ambitious. We both knew that extensions of this project would be worthwhile. And I had also continued to work on the computational side in this project with Ethan Vishniac. And, in fact, I had developed a very nice one-dimensional hydrodynamics code, working independently with the guidance of Professor Antony Jameson in the Mechanical and Aerospace Engineering Department.

So I had these tools and I thought I'd bring them together with my original aspirations of studying the interstellar medium, using radio astronomy, to study the interstellar medium during galaxy formation, computationally. So I wrote a thesis proposal. Ostriker realized that it was ambitious, but he also saw, perhaps, this young man is actually capable, he was able to accomplish something unexpected, so I'll let him try it. I'm imagining he might have thought something like that. So, I began that project and I met with him occasionally, continuing my style of pursuing my independent ideas and checking in with him. Then, in my fourth year, while he was on sabbatical in Cambridge, I continued to work independently. My ideas advanced pretty rapidly and eventually developed into a very nice thesis although it was late. I missed the four-year graduation mark at Princeton.

Zierler:

And I'm curious, when you joined forces with Ostriker, in the mutual acknowledgment of each other's work, how did that change the collaboration? Were there items that you had worked on that he had not and vice versa?

Bertschinger:

In fact, Ostriker was a rather hands-off supervisor. I think he appreciated students who showed their own leadership. He really loved to discuss the science. He was he was drawn by the subject matter and perhaps less by the art of mentorship. He was a fine mentor for me, although some of his students felt that they would have appreciated more guidance. I was so independent that working to his style was actually quite beneficial. So he had no expectations that we would collaborate and publish together. And, in fact, aside from the paper with Vishniac, I don't believe that we coauthored any papers. The papers that came out of my dissertation were solo publications.

Zierler:

Now, on the administrative side of the more substantive questions differing on cosmology and astrophysics and astronomy where, exactly, within Princeton were you located? Departmentally, I'm asking.

Bertschinger:

There was cosmology in both the Department of Astrophysical Sciences and in the Physics Department. I was in Astrophysical Sciences. In the Physics Department cosmology was within the so-called gravity group, which was led by Bob Dicke and Jim Peebles, who were later joined by Dave Wilkinson, the radio astronomer. And there were a few other astronomers from time to time, including long-term staff member Ed Groth.

And, although I was a student in the other department, there was some cosmology underway there, too. Jim Gunn joined Princeton, I think, in 1980, having moved from Caltech. He was an observational cosmologist. Ostriker was a theoretical cosmologist, but more broadly a theoretical astrophysicist. So there was exchange of ideas and discussion between physics and astrophysical sciences. I think not nearly enough. But I spent time at the Physics Department in Jadwin Hall. I took classes in Jadwin Hall, Although, I have to say that was discouraged by my astronomy advisor in Peyton Hall where astrophysical sciences was located. At one point I requested of my graduate advisor to be allowed to take Bob Dicke's electromagnetism class. My graduate advisor said that's going to detract from your progress towards your degree. You need to finish in four years. No, you can't do it.

Well, I sat in on Dicke's lectures, of course, nonetheless. Later, there was one class that they were happy for me to take in Jadwin Hall, and that was general relativity. So, of course, I did that. And Jim Peebles was on my dissertation committee where he offered really valuable feedback and insight. So I was I was very pleased with the interaction between the two departments. But it was, between the faculty, not as much as you'd hope for.

Zierler:

It sounds like you really made the best of both worlds by your own connections, in terms of who you were working with.

Bertschinger:

I did. You know, in retrospect, it would have been nice to have had a complete fifth year there. They didn't really change the policy until somewhat later and I finished at Princeton basically after four and a half years.

Zierler:

Who else was on your committee?

Bertschinger:

Jim Gunn. Of course, Jerry Ostriker, as my adviser. And Richard Gott. I forgot to mention Richard Gott, another prominent theoretical physicist, cosmologist, and polymath in Astrophysical Sciences at Princeton. My thesis committee was wonderful, superb. They gave outstanding feedback. I was really thrilled to feel competent in their company and to have their recognition of the quality of my work.

Zierler:

Perhaps you were asked this at the defense or you thought about it just on your own. To the extent that a graduate student is able to have such grandiose thoughts, what did you see as the contribution of this project toward some of the broader questions that were in the field at that time?

Bertschinger:

I don't believe that question was asked, but it's a very appropriate one. I defended my thesis in late 1983, and although my work in cosmology had begun with pure hydrodynamics, that is, with the motion of atomic matter, it evolved to include substantial work on dark matter. Dark matter was just starting to become a big thing in the late 1970s, thanks largely to the astronomical work of Vera Rubin and her collaborators. And, accompanying theoretical work by a number of people, but especially the work of Vera Rubin who was highly influential and I was aware of this. I felt like a little bit of an outsider to this for a couple of reasons. One was the fact that this really seemed to be physics. Even though Rubin was an astronomer, the sense was, this surely must come from theoretical physics in some way. And, as I said, I felt, even then, perhaps a little bit of an outcast from theoretical physics. That is a silly feeling in retrospect, but it was something that I felt following my freshman and sophomore electromagnetism instructor's remarks.

Zierler:

Silly because, Ed, nowadays that these intellectual divides are far, far lower and less influential than they might have been 40 years ago?

Bertschinger:

That's exactly correct. And then the other side of it, rather than personal, was just simply the cultural. That the Department of Astrophysical Sciences had an interesting relationship with the more theoretical cosmology framing. I think in some ways the astronomers, including those in Peyton Hall, were occasional gadflies or critics of some of the ideas coming from high energy physics.

Zierler:

After you defended, what were your aspirations? What were you looking to accomplish next?

Bertschinger:

That's a really interesting question for reasons that I haven't yet mentioned. One is that in graduate school, I really developed a strong social conscience, in two ways. First, I spent my summers as an instructor at the Summer Science Program where I had been a student. So half of my summers I spent teaching in Ojai, California. That was highly unusual then and it's highly unusual now.

Secondly, I became a Nuclear Disarmament activist. I was active in the Campaign for Nuclear Disarmament. I worked as a campus and community organizer while I was in graduate school. This was in 1981 and 82. I was deeply concerned about the escalating tension between the US and the Soviet Union driven, it seemed to me, largely by the rhetoric of the Reagan administration, and there was a growing worldwide movement calling for a nuclear weapons freeze. As I said, I became an organizer in that effort.

Zierler:

Ed, I'm sorry, just to interject there. To what extent did your physics background specifically inform your political feelings about nuclear weapons and an aggressive military posture and what would later become SDI?

Bertschinger:

I had written a paper on, or was in the process of writing articles on explosive galaxy formation. I was intimately familiar with the modeling of nuclear explosions, and I even took some of the Soviet work on detonation waves and applied it in cosmology. I wrote a paper called Cosmological Detonation Waves. So, I was really deeply familiar with the consequences of explosions and detonations. I don't know that this had a political bearing on me, but it certainly made me hyper aware of the dangers of nuclear weapons.

Let me add, to finish the story, that in 1982, perhaps shortly after receiving the affirmation of my work from Ostriker, I decided to apply to the U.S. State Department to become a foreign service officer. I was so alarmed by the nuclear arms race that I began to question the value of a PhD in astrophysics and, really, any other technical discipline. I felt that what the world needed was more diplomacy and less perhaps destructive science. Although I didn't phrase it as destructive science at the time.

Zierler:

Ed, just to play devil's advocate, of course, it was physicists who made the nuclear arms race possible. Did you ever think that you could cause more change from within?

Bertschinger:

Well, not immediately. [Laughs] I'll come to that. So I applied for the Foreign Service role. They had an examination, which I did very well at, a written examination. And then I went to the State Department in Washington, D.C., or maybe it was in Arlington, Virginia, for a day of interviews, along with all the other candidates who were applying for foreign service officer positions. That was a really eye-opening experience for me. It revealed to me my naivete. And led to a very happy outcome.

Both the State Department and I recognized that I was not meant to be a foreign service officer, at least at that time. I had neither the life experience nor the practical skills to navigate living in another country and to contribute effectively to the mission of the foreign service. Moreover, my views that this would somehow lead to diplomacy were quite naive. I discovered that only after many years did foreign service officers ever achieve the opportunity to do the kind of diplomacy that had inspired me.

Zierler:

Not only that, Ed, but I might interject there that in pursuing that career path, the decades that would it take for you to have achieved a political relevance would have been far beyond the Reagan administration anyway.

Bertschinger:

Exactly right. I recognized that. And I returned with greater clarity to complete my PhD work. But I made a promise to myself at the time. And it was that wherever my career took me, and I did aspire for a faculty career, but wherever my career would take me, I would always strive for equity and justice in the role. Whatever roles that I held. And that was a deeply formative experience for me.

Now I have to say one other thing about the transition out of graduate school. Given that the scale and ambition of the projects I was working on and the fact that I was working so independently, I was rather slow to publish. When I was applying for postdocs, I had just one publication and it was a very fine publication. It was the one that Ostriker commended, but it was really much too slim of a publication record for someone in the field even at that time. So as a result, I was not receiving post-doctoral offers. This was in the late winter of my fourth year.

So in February or so, by which time many other students had received their postdoc offers, I began to apply for industrial positions. I was preparing to marry my girlfriend. She had begun a position at the Patent and Trademark Office in Washington, D.C. And, so, I looked for opportunities in that area. I applied for a promising job at a small aerospace company outside of Washington, D.C. with a NASA contractor. I went for an interview with the CEO. He said, at the conclusion of that day, that he felt that I would be a wonderful employee, but, he said, “Why should I offer you a job? You're just going to get a postdoc.” I said to him, “Sir, I have no postdoc. It's late in the season. I would be grateful for the job.” He said, “Contact me again after five days and we'll talk then.” Three days later I got a postdoc offer.

Zierler:

[Laughs] Maybe he was a prophet.

Bertschinger:

And so I called him and I said, “Sir, you were right. I got the postdoc. Sorry about that.”

Zierler:

And I want to just make sure we're very clear on your intellectual odyssey. So, I mean, you write an important thesis. You're showing a tremendous amount of promise. You have the support and admiration of, I mean, it's as good a committee as one could come up with, even if you were to combine different people from different institutions, right? This is all leading on a very strong trajectory toward academic success in your field. And so between your interest in the State Department, where it sounds like, at least hypothetically, you were entirely prepared to walk away from it all and your interest in pursuing work in industry, can you sort of fill in the context of your longer term aspirations and what you were thinking you had to offer society?

Bertschinger:

That's a wonderful question. As you might expect, my early thoughts about that were much less well-formed than they are now. Each of us constructs our own identity with life experience. What I've come to realize is that from an early age the two chief values for me are education and justice. I mentioned some of the reasons why both were important to me. Justice perhaps is unusual for a physicist or an astrophysicist, although less so today. It's actually becoming quite an important topic for people. But it was important to me well before graduate school. When I was in high school, I read books from the Government Printing Office. My father discovered that this was a nice place to order books. And so we would order books including one volume on the U.S. Constitution, its history and interpretation. And there was a volume on the first amendment written, or maybe prefaced by, Justice Douglas, that just captivated me. So I was really interested in issues of law and justice and even consider that as a possible alternative route had I not gotten into, let's say, Caltech.

So I always had this dual framing, and I think a big part of that is my upbringing as a first generation, low-income student and first-generation immigrant. A mother with an 8th grade education who didn't speak English coming to this country. It's just part of my cultural upbringing. When it came to graduate school, I had a lot of doubts about my own capabilities. As I said, my ambition exceeded my preparation. And I didn't have the kind of guidance and mentoring that would set me straight and say actually you're on a fine trajectory, maintain steady course. I had suffered enough hardships, including family challenges, that I felt compelled to always construct alternatives for myself, a backup plan. And that's kind of a practice that I maintained in many ways through life and in which became important as I began to look at the two sides of my interests, the astrophysics side and the more humanistic side.

Zierler:

So becoming a full professor ultimately at MIT., to borrow some phrasing from earlier in our talk, you know, referring to Pasadena, that may as well have been a moon away as well.

Bertschinger:

Yes, that's right. And even to receive a faculty offer from MIT. was astonishing to me. I definitely felt imposter syndrome while visiting and interviewing at the place. And then to receive an offer from Harvard and to negotiate between the two places was rather extraordinary. So that ramped up my ambition level a bit. I, of course, aspired to do well and to achieve tenure. I would say I had the expectation of it because by that point I did realize that I'd done good work and I was capable of doing that. But I saw that it was a struggle. I saw many peers were failing to get tenure and were quite dispirited by it. I was hopeful and optimistic and just maintained the practice of my Finnish sisu.

Zierler:

Clearly, you must have done significant work during your years as a postdoc. So let's talk about that first. At the University of Virginia, did you look at this as an opportunity to further improve your graduate research? Or did you want to take on new projects at that time?

Bertschinger:

I wanted to take on new projects, absolutely, although I did have to publish the research coming from my dissertation. So my thesis was not written in publication ready form and it required some work to put into articles. And that took a bit of time. But then I really wanted to work on new projects and had the wonderful opportunity of doing so with Roger Chevalier at the University of Virginia. He was a wonderful mentor and adviser, he had great ideas. I thoroughly enjoyed working with him. I'm really pleased and proud of the few works that we did. I don't remember if I have one or two articles with him. It wasn't many. He was one of Ostriker's students, and that may have been a reason why he offered the postdoc to me despite my slim publication record. He perhaps knew that to achieve this while working with Ostriker, and perhaps recognizing the strengths of Ostriker’s reference, that those were indicators of my potential beyond the thickness of my dossier.

So that was great. He led me to some projects on the interstellar medium and supernova explosions, which, as I said, were an early interest of mine in the cosmological context. And I thoroughly enjoyed that. I did well. I wrote a series of first author publications at that time. And then, that led me after two years to a postdoc at Berkeley, where I was a Miller Fellow. I think my success working at UVa together with the recommendation of my dissertation made it easier for me to get the more sought-after roles. So I became a Miller Fellow, a prize postdoctoral fellow at UC Berkeley. There I worked with Chris McKee. Continuing the work on interstellar medium and supernova explosions. But I also worked with postdocs and other students who were in Campbell Hall doing astronomy. Even though McKee was my formal advisor and his primary department was physics, I resided in the astronomy department in Campbell Hall. It was then, as it is now, an intellectual mecca with lots of vitality in theoretical astrophysics. And I thoroughly enjoyed both culturally and scientifically living and working there for a year.

Zierler:

Ed, what were some of the significant technological advances in the field that were relevant specifically for your research at the time?

Bertschinger:

One of them was the development of charge-coupled device detectors, or CCDs. They entered astronomy from the Air Force. Of course, they originally were used for military imaging after an astronomical development. So there was an interplay between astronomy and the military with regard to, actually, several technologies. It was with gamma ray detectors as well. There were satellites, for example. But CCDs greatly increase the quantum efficiency of detectors and allowed for much deeper observations so that astronomers could really do observational cosmology in the optical and eventually infrared spectral bands, something that was really difficult to do in the early days of Hubble, Humason and Sandage. So that certainly had a big impact on the field. There were other electronic detectors, reticons and so on that Vera Rubin and others began to use that again made the measuring of rotation curves and the evidence for dark matter accumulate much more rapidly. So that was probably the number one thing at the time.

Eventually, a little bit later, I would say underground detectors like the Sudbury Neutrino Observatory, Kamioka, and Super-Kamiokande detectors. The other underground laboratories which became neutrino observatories following the supernova of 1987A in the Large Magellanic Cloud. That was absolutely transformative for astrophysics and really began the merger of astronomy and physics and cosmology together into the emerging field of particle astrophysics.

Zierler:

As you were maturing in the field through your postdoc, did you find that you were asking different questions than the ones that originally animated your dissertation interests?

Bertschinger:

Absolutely. Like many scientists, I revel in the questions more than the answers. As a student, I admired the brilliance of the faculty and the more senior students and postdocs around me who were able to ask amazing questions. And I was so curious and driven to understand the universe that I kept asking questions. And, eventually, with experience, I was able to ask many insightful questions. What I found as a postdoc was my ability to find good scientific questions exceeded my ability to answer them. When I was completing my doctoral thesis, I began making kind of a projects list that I'd keep in a notebook. I had ready-made started projects that really helped to accelerate my progress at University of Virginia. Although, as I said, Roger Chevalier brought some really important additions to that list.

But by the time I arrived at UC Berkeley, the ideas were coming fast and furious and I could no longer keep up with them. So I kind of decided that, well, I'm just going to just put my list out there and share with people and we'll see what collaborations results or what other what ideas people pick up on because there's no sense in... Well, I realized that the purely independent approach to research was not the most effective one and that collaboration and sharing ideas with others was the way to go.

Zierler:

If you can freeze as a moment in time, your thoughts on this from 40 or 35 years ago, would you have thought, fast forwarding to 2020, that dark matter would remain this fundamental mystery that it is?

Bertschinger:

[Laughs] In those days.

Zierler:

I mean, how much excitement was there that, you know, the field was on the cusp of fundamental discovery?

Bertschinger:

Oh, there was a great deal of excitement. There were two ideas from particle physics that had thoroughly infiltrated cosmology by the early 1980s. One was dark matter. There was a growing belief in the existence of dark matter. Even though there were still a few skeptics, the evidence was rapidly mounting and this was beginning to transform the astronomy field, let alone cosmology. The second was the development of inflationary cosmology in the early 1980s.

Zierler:

And were you, Ed, were you following Alan Guth's work at all during those years?

Bertschinger:

Well, his landmark paper was, I believe, published in 1980. I was still a graduate student at Princeton in astrophysics at the time. And that seemed a rather distant to me. I didn't really understand it. It didn't immediately impact astronomy. Of course, it had its impact in physics, but it took some while to reach astronomy. Even by the time I was finishing my doctoral thesis in 1983, inflationary cosmology was just a phrase that people were talking about. It was not the deeply impactful concept that it later became.

However, by the time I became a postdoc, especially at UC Berkeley, inflationary cosmology was being talked about much more broadly in the field. And, moreover, the very idea that pure theoretical physics and mathematics could construct plausible, testable theories of nature was pervasive. It was not accepted by all astronomers. There were still many skeptics about inflationary cosmology and other ideas, but it had begun to transform the field. And, in fact, I was drawn into the interface between particle physics and cosmology not through inflation, but through cosmic strings. Cosmic strings are hypothetical objects. They're not elementary particles, but rather they are linear topological defects in a background field pervading the universe. They may or may not exist. But, if they do exist, they have a gravitational effect, and they could even be the progenitors of galaxies.

Since I had done a thesis on dark matter and galaxy formation, I was really eager to learn more about the possibility of cosmic strings seeding galaxy formation. And I have to say, I came to it as a skeptic. But this marked my return to cosmology. After finishing my dissertation, I kind of turned away from cosmology to work more on the interstellar medium and hydrodynamics. But when I was at Berkeley, cosmic string interest was just growing phenomenally. I had seen talks and read some papers and thought, well, I developed some methods in my dissertation to deal with this problem. So let me look at it.

Zierler:

And where did you see at the time cosmic strings fitting into broader questions in string theory, super gravity, super symmetry? Where did that fit in?

Bertschinger:

At that time, I really had no conception of the connection between them. I had not studied quantum field theory at that point. To me at the time. grand unified theories, supergravity and supersymmetry were merely words. I had no concept of why they were so attractive to theoretical physicists. It seemed like a different discipline altogether.

Zierler:

And so, for example, you would not have spent time with, significantly with, somebody like David Gross during your Princeton years?

Bertschinger:

That's correct. Although, in the early 1980s, well I guess it might have been 1984, I went to a workshop at the Institute for Theoretical Physics in Santa Barbara. Now, David Gross was not the director at the time, and, of course, he was at Princeton.

Zierler:

Right.

Bertschinger:

But, you know, there was a lot of this stuff in the air. And there was a there was a pair of workshops at the, then, ITP. One that was on kind of superstring related things. And another on cosmic strings. And so I did see some of the connections there. I was mostly learning from people like Neil Turok about that. And, his work, his boldness from particle physics to astrophysics inspired me. It actually inspired me in a critical sense, in that I thought that his ideas were not fully formed and may be incorrect. So I wanted to see if I could disprove them. But they were not so poorly formed. They actually were really difficult to disprove. And perhaps even to this day, in some variations cosmic strings seeding galaxy formation has some viability. It was a quite wonderful theoretical idea to work on. And I give to Neil Turok a lot of credit for crossing that bridge of disciplines. And there were, of course, others later who did. Those who worked on inflation. People like Michael Turner, certainly Dave Schramm, who was a great inspiration to me and a mentor in some respects. And those people all inspired me to pursue this interface between astrophysics, cosmology and particle physics.

Zierler:

Ed, I want to ask sort of a broad question at this point. You were so well positioned in the way that you crisscrossed the country at these elite institutions. Did you sense overall that there was an East Coast way of doing physics on a West Coast way of doing physics?

Bertschinger:

No, I didn't. And that's probably because I identified myself more as an astrophysicist than a physicist. The astrophysics community, of course, has its own divides. Some of them are geographic, a bit like the East Coast and West Coast physics cultures, which, you know, might have been originated in key leaders like perhaps Rabi at Columbia or Johnny Wheeler at Princeton or Lawrence and Oppenheimer at Berkeley. In astrophysics and astronomy, the divides were in many ways a bit pettier. They had to do with competition about glass, who could build a bigger telescope. There's been a very strong tradition in astronomy, certainly in the 20th century, of gamesmanship, of striving to build ever larger observatories. Of course, the same was true in particle physics as revealed in the memoir or, for example, Carlo Rubbia. But I didn't really know about that at the time. I was more in the astronomy and astrophysics world. And there I saw the great rivalry between the two different camps on the Hubble constant.

Zierler:

Who are some of your most significant collaborators when you were out at Berkeley?

Bertschinger:

You know, I was such a short time at Berkeley. Around the time I accepted the Miller Fellowship, I got a call from MIT. in fact, I think it was the second call from MIT. I maybe even had gotten a call from them earlier, but this time asking if I would apply. And I did. And, as I remarked, I ended up getting faculty offers during that year while I was at Berkeley. So I had hardly the time to begin many new projects or complete collaborations with people at Berkeley.

But there were still a couple of people that were influential and with whom I did later complete papers. One, as I mentioned, was Chris McKee. And I wrote a paper on Supernova Remnant Evolution with Chris and then graduate student Dennis Cioffi. Another was Roman Juszkeiwicz, a Polish cosmologist who passed away, sadly, a few years ago. A brilliant man, a wonderful thought partner in so many ways. Together with Nicola Vittorio, another brilliant and thankfully still living Italian cosmologist, we shared an office in Campbell Hall. And so we had many conversations about developing ideas in astrophysics and cosmology. I later wrote, I think, a couple of papers with Juszkeiwicz. But, as I said, I really didn't have time to develop further collaborations before I started my faculty position at MIT. I didn't know it at the time, but I could have deferred for a year. As I said, I was first generation, low income. I really didn't have much mentoring or guidance. I didn't know what my full range of options was. And I thought, well, okay, let me just... I'm on an ascent. Let's go for it. In hindsight, I think I might have benefited from spending another year in that wonderful intellectual and cultural venue at Berkeley.

Zierler:

How intensively were you on the job market by the time that the MIT opportunity became available?

Bertschinger:

Well, I had applied to a few faculty positions already at the same time as I was applying for the Miller Fellowship. I had gotten on some short lists prior to applying to MIT. I think I had made visits and was on short lists at UCLA and University of Washington, Seattle. Then, the following year, I applied to a few more places, not a great many because I figured I would have a second year as a postdoc if I didn't get offers. So I didn't feel urgency about it. But I was persuaded by the arguments of the people that Harvard and MIT don’t have openings every year, you should apply.

Zierler:

[Laughs] Did you get a sense that there was anybody specifically on the faculty at MIT who was championing your candidacy?

Bertschinger:

Yes, I did, to some extent. And there was a bit of an irony there. As I mentioned earlier, MIT was not really viewed broadly as a place for astronomy or astrophysics. There were a few astronomers and astrophysicists ever since the 1960s, primarily in cosmic ray physics and astrophysics, with Bruno Rossi being a world leader. Then radio astronomy with Bernie Burke. But, by that time I was no longer doing radio astronomy. And then Phil Morrison moved to MIT and he was, of course, a great polymath who did work in cosmology and much else. But the greater draw may have been the young theoretical astrophysics group who were hired a few years prior, Scott Tremaine, Len Cowie and Charles Alcock. These were three brilliant young theoretical astrophysicists who were brought in as a cluster hire to jumpstart the theoretical astrophysics program at MIT. I admired them all. When I visited MIT, I was hosted by Alcock. I really wanted to join the three of them as a young colleague. I was inspired by their work.

The great irony is that after or maybe around the time I was offered a job at MIT, Alcock was denied tenure and I moved to MIT and physically took his office. That was painful for both of us, but surely for Charles. And then Cowie and Tremaine left a few years thereafter. So this wonderful theoretical astrophysics group that had been started dissolved and I think may have led to some of the astronomy and astrophysics faculty in the area feeling that it was a dangerous place to stay and pursue tenure. But as I mentioned earlier, I did so with optimism and hope and was successful.

Zierler:

In what ways did you sense possibly that your own tenure prospects might be problematic? Just because this was MIT and these things happen.

Bertschinger:

I didn't think about that. I had, by that time, recognized that having a backup plan at each stage of my career had served me well, even if I ended up not pursuing that backup plan, such as serving in the State Department. So I felt reasonably confident that I would be able to land on my feet regardless of what happened. And I simply wanted to pursue, with all my energy and passion, the things that I loved doing. And that's how I approached it.

Zierler:

OK. Did you take on graduate students right away?

Bertschinger:

I'm trying to remember. I think I took... I think I waited a year and before taking my first graduate student, who was James Gelb. And then, within a year or two, I took two additional students who had begun working in the Center for Theoretical Physics and switched over to working with me. John Tsai and Chung-Pei Ma.

But I'll mention that I worked extensively with undergraduates. When I came up for tenure and submitted my tenure package, I had, I think the last was being completed in the year of that tenure dossier... I had supervised ten undergraduate theses. My first doctoral thesis that I supervised was not completed until maybe the year that I got tenure. I think perhaps 1992. So it was really quite unusual for somebody to have completed supervising so few PhD dissertations by the time of tenure. But it was equally extraordinary for somebody to have supervised ten undergraduate theses.

Zierler:

Ed, to switch over again to the social side. In what ways was your interest in social and economic and gender justice, in what ways were these changing or becoming sort of more solidified? Now that you were a faculty member proper.

Bertschinger:

That's a really important question. I would say there were really two related things happening. First was that I was becoming a teacher and mentor. These were opportunities for me to apply my ideas of equity and justice to help others advance. I was in a discipline that was not very diverse and in a department that was not very diverse. And I knew that my primary task for a number of years would be to put my foot down on the accelerator and get as much impact in research as I could. But I found it tremendously exciting and fun to work with students. I think that's why I supervised ten undergraduate theses. I just loved teaching and mentoring. And that was an expression of my social side, of my interests.

But there's another very important aspect here, and that is the culture of physics at that time. In the environment where I was working on issues of racial or gender justice were absolutely foreign concepts to most physicists. It's interesting that, at that time, MIT Professor Vera Kistiakowsky was a prominent advocate for women in physics and she, in fact, founded or led the movement that founded the Committee on the Status of Women in Physics in the 1970s. I got to know Vera because she left high energy physics to move into astrophysics. And so I enjoyed talking with her both about astrophysics and a little bit about issues of gender equity.

Though at the time I kind of was absorbing the predominant narrative of the field, which is: Just put your nose to the grindstone. You've got to beat everybody else in this field. Your tenure is going to be decided by your individual impact. Those were the messages that I heard. And I, to some extent, internalized those messages.

And, that then led to a serious call to account. After I got tenure, I began to question the norms of the profession and the behaviors going along with this kind of intense competitive style. They were at odds with what I saw in my mentoring relationships with students, and they were at odds with my internal ideas about justice. I found that with success came rising expectations. Many wanted me on their collaborations and expected me to be fierce. At least that's how it seemed to me. I realize, in retrospect, that's actually not true. There were many people who were put off by how hard driving I was. But it took me awhile to understand the harm of this.

After I got tenure, maybe a year or so afterwards, and my career was really on a meteoric ascent at that point, I was personally struggling and I had some personal crises really rooted in the conflict of values between my desire for justice on one hand and the ways that I was behaving in the profession. There were times when I, as a very successful tenured faculty member, I just found myself in tears walking through MIT.

Zierler:

Ed, what would be a representative example of this sort of poignant moment for you?

Bertschinger:

I remember vividly one astrophysics colloquium talk given by a visitor where I was... I can only describe myself as a harsh inquisitor. I perceived, rightly or wrongly, some inconsistencies or difficulties for me with the research line that this person was taking and I began some aggressive questioning. Afterwards, even though nobody said anything to me about it, I felt shame at how harshly I had questioned this outside speaker. In fact, what I was doing was normal. Maybe that's why nobody questioned me about it or commented afterwards. But I felt shame at my behavior. It was another time...

Zierler:

Shame, what? That you were being unfair?

Bertschinger:

Yes, that I was being inhumane, frankly. That I was calling out this person not using rude language, but using a kind of, frankly, masculine rhetoric that is deeply upsetting, although it was normal, as I say, in the profession and was regularly practiced by others in that or in other settings. Maybe I was a bit harsher than most of those I had observed. And I was deeply ashamed of it.

Another example of this was I was asked to give a colloquium, again in astrophysics, criticizing a theory of a mathematician at MIT who. This man was a contrarian and had developed an alternative theory of the universe, which involved something like what we now call modified Newtonian gravity. Or, in other ways was contrary to the prevailing theories. And I was recruited by my colleagues to give a colloquium talk that would disassemble that man's theory. And I did so politely, but the entire premise for that colloquium was inappropriate, I realized.

My shame about these events had the most profound impact on me of anything in my career. I stepped away from that steeply rising ascent. And, I said to myself, I don't want to do this anymore. I really don't. And it wasn't just those experiences I was having at MIT. The kind of behavior that I'm describing was actually commonplace in cosmology. And I despised it. I felt very uncomfortable when my cosmology colleagues would attack each other viciously at conferences. Some of it was the Hubble constant controversy. But some of it was also promulgated by different schools of thought in theoretical astrophysics. And some of it was quite obviously directed towards women. It was really evident how few women there were in cosmology. And those few who stayed had developed very thick skins.

This disturbed me so badly that I basically became inactive in cosmology. I became a refugee from the field of cosmology because of the toxic masculinity that was pervasive in the field at the time. Many years later, I came to study sociology and I learned that there is very good research on this phenomenon, which rises not only in theoretical cosmology, but in many, many different practice areas. Including in the legal system, policing, academia, medical profession, you name it. I've been very inspired by work of Dr. Jennifer Berdahl at University of British Columbia and her colleagues in sociology who developed a theory called the Masculinity Contest Cultures.

And, what I was experiencing in my profession was a great example of a toxic masculinity contest culture. I didn't know what to do about it, except that I no longer felt psychologically capable of devoting myself fully to the field. I disengaged from the profession. I continued to mentor students. I stopped going to conferences. I became a father. I made the excuse to myself that, well, now I waited so long to become a father, I'm going to invest myself fully in that. I stopped going to conferences and within a few years people stopped inviting me to conferences. I did write some important papers in the decade or even fifteen years following that 1992 period. But I became a... what is the word? A recluse. I was known in name, but not seen in person, in the cosmology profession.

Zierler:

Were there people who were urging you to reverse course, to not take a particular instance so seriously and that collaboration was vital for your work?

Bertschinger:

No, no. One of the elements of this masculinity phenomenon is individualism. It’s one of the most characteristic traits. Now, individualism is not strictly a gendered construct. It actually has very strong national origin. The US is the most individualistic country in the world. That's well-documented by anthropologists. Anyway, the idea of independence—"be your own man"—was certainly then very strong in physics, in cosmology. Collaboration was not the predominant value at the time, although that has changed in the profession since then. So, no, people didn't say you should collaborate or find other ways of doing this. They, I think, kind of figured, well, Ed's his own man, this is how we do things in the profession. And, besides, he is turning out good students, so perhaps that's what he wants to do.

Zierler:

Ed, I don't want to get entirely Freudian here, but I can't help but wonder if the influence of your troubled relationship with your father might have been formative for your later ideas about masculinity and the troubles that this caused women in STEM?

Bertschinger:

That's certainly something that I recognize and have explored in therapy.

Zierler:

You mentioned that you were still writing significant papers. In what ways had your research focus shifted over these years and in what ways had it remained the same?

Bertschinger:

I think the primary shift was after tenure, like so many, I began to take a longer-term view. That is, to work on projects that might take several years to complete rather than resulting in more rapid publication. Secondarily, I stopped working in at least one subfield of the cosmic microwave background because there was a great deal of toxic behavior in that field. And I just felt uncomfortable going to conferences and associating with some of my colleagues. I want to be measured here and recognize that there are many wonderful, caring people, of course, both now, and then, in the profession. What I'm describing was my personal reaction to some of the behaviors that I witnessed or ways in which I saw other people suffering from those behaviors including my own. Galaxy formation itself was a hypermasculine field driven by the kinds of behaviors that Berdahl and company have described in their papers on masculinity contest cultures. So I stopped working on numerical simulations of galaxy formation and cosmic microwave background anisotropies just as I was becoming one of the prominent people in those fields.

The excuse I made to myself was actually ironic in hindsight. The successful people in the field were establishing very large collaborations because the scale of those computational projects vastly exceeded what individuals could do. And, again, I think this is part of my paradox with masculinity. I had perhaps internalized that collaboration with senior people in the field was not a primary value. I wanted instead to work with my students. And, working only with students, I could not compete with the larger groups. So that was also one of the reasons besides the toxic masculinity that I stopped working largely on computational numerical methods for galaxy formation.

Zierler:

Ed another... No, please, go ahead.

Bertschinger:

My interests did broaden a bit in in astrophysics and physics precisely because I was able to explore longer range subjects. And because I learned a great deal in teaching physics. So, I began working on general relativity and theories of gravitation. I worked in an area called modified gravity, which explores alternatives to general relativity theory that could play a role in resolving some of the great mysteries of the universe. I worked on non-linear dynamics. I worked on numerical methods, broadly. I worked even on field theories. So there's a wide range of subjects that I worked on. I'd say they're eclectic. They have not really targeted one specific area for being with primary focus within physics, because, in fact, my primary focus had shifted outside of physics.

Zierler:

Ed, I want to ask another question that's sort of related to your broader social and political concerns, and that is the extent to which you had and have ongoing security concerns with American nuclear policy. And, to bring it close to home, of course, to state the obvious, MIT has been closely intertwined with defense contracting and so many of these issues that are of personal and political concern to you. So, I wonder if that's been a wire for you too hot to touch or you've actually dealt with that as well?

Bertschinger:

I dealt with that in a couple of ways. You're absolutely right. And MIT is a fascinating place because it has both been a locus for new military technology to be introduced and a focal point for opposition to armament and military technologies. The latter element was highly influential for me, going all the way back to graduate school, because the leader of the Nuclear Weapons Freeze Campaign in the US was an MIT lecturer by the name of Randy Forsberg who was in the political science department. And she passed away now about thirteen years ago. But she was a great heroine to me. I just was absolutely inspired by her to get strongly involved in this community organizing effort back in graduate school.

When I arrived at MIT, besides occupying Charles Alcock's office, I was located next to Phil Morrison. And Phil Morrison had, I think, just retired, but he continued coming into MIT until some years later, shortly before his death. And Phil was a great critic of the nuclear arms race, despite having been one of the Manhattan Project scientists involved in the assembly and testing of nuclear weapons.

So these were all influences. And I'd have to say that the influence of people like Morrison and Forsberg, also Aaron Bernstein and Viki Weisskopf in Physics, and later others in the Center for International Studies in the Political Science Department, John King of the Biology Department. They were influential, but I never picked up again the anti-nuclear activism to the same extent that I did in graduate school. And that's, I think, primarily because my own evolution really pulled me much more strongly towards gender justice. And so I really began working much more on issues of gender equity rather than nuclear disarmament, although I had continued to speak with my colleagues, especially Bernstein before he passed away, recently, about this topic.

Zierler:

How do you identify yourself now professionally in terms of your scholarly interests?

Bertschinger:

I really view myself as an educator, broadly speaking. Though the focus of my efforts is in higher education, I don't regard them as being in astrophysics or physics. I teach in the School of Humanities, Arts and Social Sciences. I teach a course on science activism. I'm looking forward to developing additional courses, including perhaps one on men and masculinities, but certainly others on cultural change. I identify myself with a larger movement in the STEM professions and perhaps in higher education in general to transform the culture of education to be much more inclusive and equitable than our current practices in the fields.

Zierler:

Has it been difficult for you? Please, please.

Bertschinger:

Go ahead.

Zierler:

No, I was going to ask, has it has it been difficult for you to navigate or to make the case for an ongoing appointment in the Department of Physics? Or do you see that as a square that's easily circled?

Bertschinger:

I think I'm very fortunate in being able to navigate that. So, to understand that, one has to understand the triad of higher education that's regularly used to describe what it is to be a faculty member. We tell people that being a faculty member involves three things: research, teaching and service.

The physics department has always valued service, particularly service to the nation. The department has had presidents of the American Physical Society and other professional societies. Ernie Moniz was the Secretary of Energy in the US government. Many have served as governmental advisors. I think this was established through the leadership of people like Viki Weisskopf, who was a beloved leader in physics, who I got to know. But there were also many other people with a broad view of the role of education and physics. So therefore, the department has been very supportive of my becoming involved in leadership activities.

I was the head of our astrophysics division for a few years and then became the head of the physics department for six years. And then I became an administrator in the central MIT administration working for the provost as MIT’s inaugural senior diversity officer. Well, the title was different. It was Institute Community and Equity Officer. And that was where I was able to really begin to put into practice the things I was learning and advocating for around equity, gender and racial justice and so on. I've really had no significant criticism from my departmental colleagues about that. Of course, there is a range of views about these topics and not everybody feels, well, in fact, most faculty don't believe as strongly as I do in these things. But I would say that there's largely been respect for faculty to conduct their interests provided that they carry their weight in departmental service and teaching.

While I was in the central administration and even while I was department head, I generally did not teach aside from doing freshman advising seminars occasionally. But now I am back to full time teaching and I am certainly carrying my education and service load within the department. So, no, I don't get pushback from my colleagues. If anything, I think I get perhaps some measure of respect for having charted an independent course. And this is in keeping with many others in the department, including the last few department heads.

Zierler:

Ed, of course, one of the primary objectives of the day, we now know as #ShutDownSTEM was to call attention to so many of the issues that too many people in the physics community, in the STEM community more broadly, were either unaware of or willfully blind to. And so, I wonder, as a European American male, if you saw yourself, in this moment in time, particularly well positioned since you have been thinking about these things long before, perhaps almost all of your colleagues. In what ways have you found that you are now particularly well positioned to seize on this historical moment? You know, from your dual identities as an eminent physicist, astrophysicist and your longstanding social, gender, political and economic concerns. In what ways do you think that you have an opportunity now to move the community forward in as productive and positive a way possible?

Bertschinger:

There are many efforts and they long predate the #ShutDownSTEM effort. During the last three years, I've been working on major projects with several professional societies. I was a coauthor of the American Astronomical Society Report on Diversity and Inclusion in Astronomy Graduate Education that was released in January of 2019. I was a co-chair of the American Institute of Physics TEAM-UP Task Force, which issued a major report in January of this year about African-American undergraduate students in physics—the reasons why their numbers have not grown like those of other racial and ethnic groups in physics and what we can do about it. I've been actively involved in an effort of the American Association for the Advancement of Science called SEA Change, or STEM Equity Achievement Change, which is a cultural change initiative aiming to help encourage universities and, ultimately, STEM departments to become more inclusive and equitable by holding themselves accountable and receiving certifications in the process of advancing equity. This is modeled after a longstanding, successful program in the United Kingdom called Athena SWAN.

And in the last two years, I helped to develop and implement a major cultural change network for the whole profession of physics and actually reaching into astronomy called APS-IDEA, the Inclusion, Diversity and Equity Alliance. This is a lot of work. I think in many respects it's far too much for me. I would say, against my better judgment, perhaps, I undertook so many projects. But I recognize that they're extremely timely. The APS-IDEA project, when we proposed it and received funding from the American Physical Society, we imagined forming a network of 25 or so, maybe up to 30, departments who would form a community of practice and learn from one another in developing cultural change initiatives within their departments. Instead we had well over 100 teams apply, and we have almost 100 teams now in the network. We were imagining that we might get 50 teams after two years. We have nearly 100 teams after less than one year. To compare with the meteoric rise of my career early on, this has been a much steeper growth of impact.

Zierler:

How do you measure that? What's the feedback mechanism?

Bertschinger:

Well, of course we do project assessment. We have expert evaluators within our team. We do a qualitative analysis of the applications from our teams and of the workshops that we hold. We get feedback from our participants. Of course, we're only at the beginning. We've just launched our network. We've warned our teams that lasting cultural change takes typically ten years or more, a minimum five years before you can expect to see real effects. You have to be invested for the long run. And what we're doing is to build a community of practice that will enable campuses to sustain their efforts over those many years. So, we can't point to successes like saying, well, as a result of #ShutSownSTEM or APS-IDEA, department X is doing practice Y. Although, perhaps there are examples. That's not our goal. Our goal is to build the capacity for sustained long-term change. As I like to say, if we want to change the profession, we have to start by changing ourselves. Every one of us, every one of us. It has to be that the realization we have following #ShutDownSTEM actually becomes internalized in the practices and values of the profession. That's the only way lasting change will happen.

Zierler:

Meaning, of course, that it's not just the day on the calendar. That misses the entire point.

Bertschinger:

It's not the day. It's not the year. Maybe it's the decade.

Zierler:

Ed, I think from my last question, I want to ask you, because it's such a fascinating and important career transition. First of all, because MIT in so many ways sets the tone for STEM in general in the United States...In what ways does your affiliation with MIT give you the ability to implement the change that you want to see in unique ways? And what personally and professionally do you want to concentrate on for the remainder of your career?

Bertschinger:

OK, first about positioning. There is no question that MIT is perceived in physics and in the STEM professions at large as being a leader. It is influential. When initiatives begin at MIT, they often spread elsewhere. A great example of this, similar to my own work, my own aspirations, was Nancy Hopkins' Women in Science study in the 1990s. It led to an awareness of gender inequity for STEM faculty broadly across the US and the world. It led indirectly to the establishment of the NSF ADVANCE Program, and its impact continues to this day. That's one of the values of the MIT brand name.

But this also comes at a cost. The cost of perpetuating a hierarchy of who's valued and whose voice is heard. It troubles me that as a senior white male cisgender straight physicist at MIT, my voice might carry further than those people without those identities or characteristics.

Zierler:

Wouldn't you grant yourself a pass, though, given how you're choosing to use your voice?

Bertschinger:

I can never grant myself a pass. All I can do is acknowledge my identities and perspectives, return always to my values and seek to elevate the voices of those that don't carry as far or as fast in the profession. And unless I am thinking about that every day—even if I am thinking about that every day—I make mistakes. I am blinded by my own bias. This is as important a recognition for me as the statement that dark matter exists in the universe.

Zierler:

And so the question about how you want to choose to focus your energies in the future, what are the things most important to you that you want to accomplish?

Bertschinger:

I want to see the cultural change initiatives such as APS-IDEA become securely established in physics and related fields and then spread to others. My greatest hope is that the injustices that many people have seen in 2020 will lead to a rising tide of justice that transforms society. I know that's idealistic, but unless we are guided by ideals and values, we have no clear direction. I'll be devoting myself to this work and to mentoring younger scholars who want to pursue similar goals for the remainder of my professional career.

Zierler:

At the end of the day, are you more bullish or bearish that's the things that are now most important to you, you will live to see the structural changes necessary to have some of these visions realized?

Bertschinger:

I am more hopeful than not that there will be significant changes in my lifetime. And that's not just because I plan to live to a ripe old age but because I have seen dramatic changes in my lifetime and I believe that there are forces at work that can lead to equally dramatic changes in the next decade.

Zierler:

Ed, it's so obvious in our talk, a theme of your whole life has been that you've always kept it interesting. And, so, I'm so glad that we were able to connect and for you to be able to share your story with me. Obviously, it's a very unique story. It's a very compelling story. And I just feel honored that you were able to share with me so openly your evolving thoughts over the years. And it's my hope that when we include this talk in our transcript that it's important not just for the historical record, but also for the historical moment that we find ourselves in. So really, I'm so happy that we were able to do this. Thank you very much.

Bertschinger:

Thank you so much, David. I'm grateful for the opportunity.