Welcome back to Season Two of The HPS Podcast, where we discuss all things history, philosophy, and social studies of science in an accessible way. I am Samara Greenwood and today I am talking with David Kaiser, who is both a Professor of History of Science and Professor of Physics at MIT.
In History of Science, David is best known for his books on the history of modern physics including Drawing Theories Apart, on the dispersion of Feynman diagrams in post war physics, Quantum Legacies, in which he discusses the history of quantum theory, and a favourite of mine, How the Hippies Saved Physics, which in part looks at how changing cultural conditions in 1970s USA, including severe cutbacks in the funding of physics and the emergence of counterculture, gave rise to an unusual group of physicists who helped rejuvenate more speculative physics.
As part of his work in history of physics, David has paid particular attention to the role of education, scientific training, and pedagogy in the production of scientific knowledge.
In a fitting follow up to Rachel Ankeny’s episode last week on research repertoires, it is my great pleasure to introduce my talk with David on the topic of scientific training.
Samara Greenwood: Hi, David, and welcome to the HPS podcast.
David Kaiser: Hello. Thanks so much for having me on.
Samara Greenwood: Now your background is in physics. So, I was wondering how you came to work in the history of science.
David Kaiser: Sure. You know, it really does go back quite a ways. As a teenager in high school, I was just really mesmerized by a slew of very good books that had just come out, kind of popular books about modern physics and relativity and quantum theory and these sort of deep kind of conundra of the early 20th century.
And a lot of those books used history or at least chronology as a kind of narrative hook. Their goal was not to teach history of science as historians would pursue it, but often these popular books would at least tell stories about the kind of grand old intellectual adventures. And they were often cast in almost hagiographic and ‘the lives of the saints’ kinds of ways.
As a teenager, I was just completely sucked in by those. I couldn't get enough. And so, when I got to undergraduate studies, the first week that I was on campus I was talking with a physics professor who became one of my most dear mentors. He was an expert in general relativity and very esoteric physics stuff.
I was sharing my enthusiasms and he said to me, he was actually the physics professor, he said, ‘there's a thing called the history of science and people do that’. It was already a revelation to me. Number two, he goes on to say, ‘and it's usually much more interesting than these saintly tales of off-scale geniuses. It's all about science and context, institutions and politics and culture’.
It was really eye-opening. This is a physicist named Joseph Harris - he was just very dear to me. It was Joe who opened my eyes in a very literal way as soon as I was maybe a week into undergraduate studies.
Even more lucky for me, not just that I found my way to Joe's door, but that Joe then pointed me toward two absolutely essential mentors in the history of science, who were at the same institution where I'd just begun studying. And those were Rich Kremer and Naomi Oreskes. And so, within two weeks of starting undergraduate studies, Rich and Naomi both had really just very kindly and generously taken me under their wings. So, I was really hooked. I was absolutely a true believer from the age of roughly 18. And I've never looked back. It's been a great joy.
And so, as an undergraduate, I essentially studied both. I did a double major, was able to work closely with Rich and Naomi on a series of historical projects, even got to do a little archival research and try to practice what it was like to do history, not just read history, which was an amazing experience that they were so generous with. And then also I continued my studies in physics with people like Joe Harris and other mentors.
Getting toward the end of undergraduate years, I thought this academic thing is a pretty good gig first of all, that seems like a pretty nice lifestyle if one could swing it. And I was so excited about both of these fields that I wound up applying to graduate school in both fields, both for graduate programs in the history of science and programs in theoretical physics and was very lucky to get to do that.
So really, as I say, I was hooked from my teenage years on.
Samara Greenwood: Fabulous. Okay. And so, then what are the advantages and challenges of working in physics and history of physics at the same time?
David Kaiser: I think there are a lot of advantages that I've gotten to enjoy over the years. One of them is that my historical work has tended to focus on fairly recent history. Really span of the 20th century, even post World War 2, as I'm sure we'll chat some more about.
Some of the physics research about which I had very pressing historical questions gets pretty involved and so I wanted to make sure I had enough of a sense to know what the historical actors were talking about. What was motivating them? What did they stay up at night working on or arguing over or so on?
I wanted to make sure I was more than passingly conversant with what the stakes seem to be like to them as near as I could reconstruct it, with the range of primary sources that we try to be creative with.
That was in addition to the fact that I just loved the physics on its own. It still feels honestly to me, these years later, like a pretty remarkable intellectual adventure, the physics side as well as the history. They have these grand arcs, and we can tell these thrilling stories that go beyond ourselves. That's part of what I enjoy about both the history and the physics, beyond the here and now, beyond my own limited horizon.
So, one of the advantages is that I can try to kind of interrogate episodes or materials from the past, the recent past and feel some confidence that I think I know what they were on about, even though it might really not be what we're doing today. And often it's subtly or not so subtly distinct, but to try to re-enter that world as best as I can.
Now there are challenges, one of which is, of course, just pragmatic. It turns out there aren't that many hours in a day. I keep counting up and I only hit a finite number every time. And so, one challenge is just trying to really clear time and a kind of mental space to delve into these projects to the degree that the projects themselves kind of deserve and require.
A little more subtly, even these years later, I still want to make sure I have something like a critical historian’s distance or historian’s sensibility. Not to just take things for granted, because that's how all physicists would agree that's how things should be done now. Not to read them back into the past, not to slip into a kind of ahistoricism, which could otherwise maybe be an easy temptation.
So, the challenges are both practical and to some degree intellectual. But, to my mind, those challenges have been far, far outweighed by the joys. That's just the special pleasures to try to immerse myself in both of those areas as a day job. It's a pretty great gig.
Samara Greenwood: Absolutely. In terms of time management, it really does blow my mind that you can manage to do both such in depth areas, both of those that you choose to do.
David Kaiser: One thing that honestly I wish we historians would get even better at, and that would be to do more robust collaboration and co-authorship. Which of course has become kind of the unquestioned norm, in other areas, including even in theoretical physics, let alone experimental physics or other areas of scientific research.
And that's something that, again, brings great, great joy and pleasure to me on the physics side, getting to surround myself with incredibly talented, hardworking, younger people, undergraduates, grad students, postdocs. And that we get to advance these projects together, really roll up our sleeves, sometimes literally, and plow forward. So that helps a lot with time management because it's not just all me and I absolutely learn new things pretty much every time I meet with my colleagues, including the students and co-authors.
I've had that experience the few times I've been lucky to co-author with historian colleagues.
Anyway, that's a plug to say, I bet we all, especially in the humanities, could make even better use of some of these kind of team building kinds of ways of approaching, thorny, difficult topics.
Samara Greenwood: As I mentioned earlier, the topic David and I chose for todays discussion was the historical study of scientific training and – in particular – the ways in which scientific training can come to shape the science produced.
As David has noted, “Scientists are not born, they are made. The ways in which this happens bear the marks of time place” – for example – “becoming a scientist in Victorian Britain was not the same as becoming a scientist in Cold War America.” (Kaiser, 2005)
I began by asking David how he first came to be interested in the area of scientific pedagogy.
David Kaiser: I think there's a maybe straightforward answer and maybe a little more highbrow or esoteric one as well. It did derive in part from my experience as a young, physics student. We take very specific classes and physics often in a very specific order of classes. One follows on from the other. And there's a fairly typical sequence.
On the other hand, even as an undergraduate, I'd hear some of my professors talk with almost like a religious zeal, like a kind of fervour, that there's one right way to teach special relativity and they're doing it wrong, or this is the way to teach quantum theory. And, you know, what do I know? This is my first time taking it.
So, the kind of pedagogical stakes seemed large, even to the people in whose classes I was attending. Likewise, there are deeply heartfelt debates about which textbook is the right textbook. And of course, they don't all agree.
And then on the other, honestly, getting immersed in readings with people like Rich Kremer and Naomi Oreskes - even before graduate school - in what then was really felt like a hot, hot topic of social construction. One of the things I got curious about early on was: how do we construct the social?
The social construction debates seem to be taking for granted that large communities - often spread around much of the globe - would somehow just agree to pose questions in recognizable or comparable ways. Like, what happened before that? What's the prerequisite to even talk about why there was widespread agreement or why something like a Kuhnian revolution might or might not ever unfold? What's the prerequisite or preconditions for that? How do we get communities or cohorts or groups of people at times and places to even recognize things as a commonly shared question, let alone as an appropriate kind of response?
So those two helped me kind of get excited to dig into - How have these routines changed over time? Even just a little casual digging was enough to convince me that the institutions in which I was immersed have a history. So, the PhD, the notion of a modern research university, these are historical objects. They have changed and they continue to change in real time. And so that helped me wonder about the institutions in which these cohorts of folks have been trained. What are the assumptions behind that? What does it take in terms of resources and politics and infrastructure and duelling priorities.
Anyway, that just felt like a kind of worthwhile set of questions to try to dig in to ask about otherwise very heady, seemingly kind of ethereal questions about quantum theory, about warping space time or whatever else was on my mind.
Samara Greenwood: One of my favourite articles of David’s is called ‘The Postwar Suburbanisation of American Physics’. In the paper David examined the training of would-be physicists in the US in the 1940s and 1950s.
He did this through studying a fabulously diverse collection of historical sources – including the annual reports of physics departments at Berkeley, Harvard, Princeton and Cornell, films produced for the Physics Science high-school curriculum, junior faculty skits, sociological research into graduate physics students from the 1950s, as well as student questionnaires of the period.
Through this research, David revealed a number of fascinating changes that occurred in the training and aspirations of graduate physicists after World War II in the USA context.
In particular he showed how the topics deemed central for teaching and research in physics narrowed significantly during this period. It shrunk away from more philosophical and foundational topics to those that were both most relevant after the war – such as weaponry, power generation and electronics - but also to those topics that could be more easily taught to increasingly overcrowded cohorts of typically middle class, white male students often whose main ambition turned out not to be to further knowledge in innovative ways, but rather to find a stable, high paying job.
Given David’s innovative historical studies into pedagogy I was interested to hear from him what he felt the key questions were when thinking about the training of scientists.
David Kaiser: It's sort of an endless list of questions. I won't make it an endless answer. I'll try not to. But some questions that really interests me are - again, stepping back - of who wants all these young people trained in the sciences? How was that a societal decision or priority that was made? It gets increasingly expensive as we look at the modern era in terms of equipment and all the rest. So, who wants all that? Why have various societies, at times and places, agreed to pay for that, let alone prioritize it with fellowships, with other policies to try to get people in those classrooms? What have young people wanted out of a scientific career as best as we can reconstruct?
People were being surveyed in real time in the 1930s, 40s, 50s, say in the United States, and those have been often preserved or published. We can use some kinds of traces, contemporaneous traces, not just the kind of afterthoughts from near retirement of older researchers.
And so, we can begin to ask, what did they think they wanted out of a life in science - what did they think that life would be all about? How have those expectations sometimes been dramatically upended by world war, by fascism, by the nuclear age, whatever it's going to be? And so even before we get to what they're learning in classrooms or for their thesis research, why were they there? What did it take to get them there and to get lots of thems there, especially when you look at scientific training in, say, post war United States.
These enrolment numbers were absolutely ballooning, and that itself I found really fascinating.
And likewise, what happens during periods of rapid change in the negative direction? So, another area that really I've thought a lot about and written about in the United States, and I think there were echoes of this or similar trends in many parts of the world, was this rapid downturn between the late 1960s and early 1970s.
This kind of post war boom in investment in the growth of universities, in the formation of new universities – this demand that looked like it would never cease. Well, it ceased pretty harshly, pretty rapidly, and it caught many, many people by surprise, between roughly 1968 - 1972 or something like that in the United States at least.
So, what happens when you have these people who have entered a multi-year graduate training program, and their main fault is finishing after the bottom has fallen out of the job market? They've done brilliantly, they did original research, they published in the right journals, they thought big thoughts and worked very hard, and their miscalculation was a geopolitical one that they really couldn't have controlled anyway.
Then we can get into more fine grained - what about shifts in sort of the subfields or the expected directions of research? Again, from some of my own historical work, I was really interested in when people who are trained in particle physics many of them had to suddenly retool in part because of intellectual reasons, largely because of these unexpected shifts in resources around 1970 plus or minus.
So how do people who are trained with certain kinds of techniques that work so, so hard to learn certain ways of framing questions, evaluating evidence, so on, what happens when some of them begin to direct those techniques or methods to new kinds of questions? What happens when they come into contact with colleagues who had been pursuing a different intellectual tradition, even in what seemed like it might be a nearby subfield? How do things that didn't even count as a question a generation earlier rise to the forefront when members who are trained in subtly distinct ways have to somehow negotiate, not always on very friendly terms?
What's going to count as good science? Who's going to prevail during debates? And part of prevailing means they're going to then win the pedagogical debates because this is what the next generation should be learning and practicing in problem sets. And this is what counts as a valuable dissertation. These are value judgments made in times and places, and they don't sit still.
I find that fascinating to even zoom in to let's say shifts within the large discipline, a little between physics and geology or biology.
I think focusing on who was trained in which specific ways - and does that help us make a bit more sense of why intellectual traditions unfold as they do. Why sometimes certain techniques get buried only to be rediscovered later. What comes to count as second nature. Because none of us are born knowing these things. Work goes in to make that feel natural.
Even though it's really contingent and is bound to change, I find that just fascinating.
Samara Greenwood: So do I, there was so much there that was really enjoyable to hear about. In your research, have you ever found that the change comes first from training, from pedagogy, like that there's a shift in thinking about how to teach? Is that ever come up?
David Kaiser: It has. So there are two quick examples that come to mind from some of my recent writing. Things I've been immersed in. And one of them is this big, big question of how should young physics students learn quantum theory? Which my friends still argue till they're really red and could be a high volume discussion to put it mildly, even to this day.
And again, with only a few moments of reflection of going back into textbooks or essays by prominent teachers and so on we begin to see this is really a moving target, and it's not moving in only one direction even, over time. There's been a tremendous amount of back and forth, a kind of pendulum swing.
For the first generation of scholars who really cobbled together quantum theory in the 1920s and 30s, many, many of them saw their role as in part explicitly or overtly philosophical. It was a quest for meaning, as well as how do I make reliable calculations?
How do I compare quantitatively with very carefully designed experiments? Of course, those things have been important. But for many of these folks, partly because of their own training as high school students, let alone in the higher education, part of what they assumed their role was to pose explicitly philosophical questions that many of them were equipped, at least to some degree, having studied some formal philosophical, say, epistemology, as young students in the German gymnasia, for example, they would have been conversant with some parts of a Kantian legacy.
They weren’t professional philosophers, but that wasn't a foreign notion to many of them. And you see that in their pedagogy, you see that in the lecture notes that survive, you certainly see that in their published textbooks, you see in the book reviews of competing textbooks. They're held up and evaluated in part by the philosophical clarity or the degree to which they engage on that level.
Okay, then we fast forward, not so forward in time to the immediate years after the end of the Second World War, when conditions have changed enormously for the training of young physicists, this new generation.
And in many parts of the world, not all, you see this kind of incredible whiplash kind of reversal where anything that could be called philosophies now derogatory. You want to get that out of there and people aren't shy about that. They call people names, they use very heated language and that's often captured in the kind of amusing phrase, 'shut up and calculate', which just kind of stood in for ‘your job is to get numbers out’.
And I want to say that's not a bad job. It's a different job. It's a different conception. And that had an immediate effect, sometimes catching younger students by surprise because they studied already from earlier pedagogical materials and they were caught like, why am I not asked this on my exams anymore?
And so that's an example where the equations of quantum theory had barely budged at all in 30 years, and yet how they were pedagogically packaged and how students were evaluated - what were the relevant skills to hone? - those really changed quite a lot. And they didn't stop changing. There's other swings, kind of other facets of that. So that's an example.
Another quick one comes a little bit later. In the 1970s, it really fascinated me. It's closer to my own research on the physics side, so it felt a little close to home. Which is the emergence of this field that we now call particle cosmology, which like its name might suggest is a kind of mixture of ideas and techniques, methods from high energy particle physics and from cosmology, trying to study the universe at large, mostly using the tools of the general theory of relativity, warping space time and the big bang and these things.
And these two areas really barely interacted, at least in the United States and some other parts of the world for a long time, even as both of them grew to a high level of sophistication. And then partly because of kind of macro geopolitical type shifts, which shifted the demand for certain kinds of physicists and institutions and so on. There was a pretty rapid re-evaluation of what all high energy particle physicists should know. And part of that was to say they should know something about relativity and cosmology, which had not been prioritized really at all for a generation or two prior.
So you start seeing people posing questions at the boundary that had simply not been recognized as a question, let alone evaluated as an answer, as recently as five, let alone 50 years earlier. And part of what shifted was PhD students now had to take a different mix of classes. Literally, they had to learn different stuff, even at a formal classroom level. And part of that begins framing new kinds of questions as curious or relevant or interesting.
It's not that the questions hadn't been posed or weren't posable before, but suddenly you have different kind of stakes for new generations coming of age under different circumstances. So these are just some examples from my own backyard, and those aren't unique, but they're ones that I come back to quite often.
Samara Greenwood: No, they're really fantastic examples, because they really bring to the concrete the kind of things that you're talking about in abstract.
Have you thought about how historical examples relate to current circumstances in the training and practice of science?
David Kaiser: One reason I'm reminded of the relevance is because I do have a seat in the physics world as well. And my colleagues and I still struggle almost every year, at least with great regularity, over things that I've seen our historical kind of predecessors struggle with as captured in notes from faculty meetings or general exam or correspondence from decades earlier.
So, for example thinking about textbooks. I'm very, very slowly, very slowly trying to write a textbook with my own physics mentor. Who's still a colleague at MIT and thinking about textbooks as historical objects. One of my favourite things to do as a historian, I love book history. I love you know, books as objects and how they come to be in the world, especially this curious subset called textbooks.
And now trying to really write one with Alan and the joke, which is really true, is that Alan keeps putting in more historical vignettes and I keep taking them out. It's like, come on, we got to get to equation three quicker, buddy. He's, in some sense, more a fan of using historical storytelling as a pedagogical device than I am.
So anyway, it's a live issue, even in my kind of day to day work now.
What counts as a really good dissertation? And it's not what I would have assumed 20 years ago or what I was trying to do more than 20 years ago myself. So, the notion of shifting realities of what's going to count as being a really, really top notch, super well trained contributor - these change.
And it's the usual historian's challenge of continuity and change. We don't want to have radical disruptions and have not been able to figure out where to go from before, but also not get stuck and not remain static.
Samara Greenwood: No, absolutely. I was wondering also, if you've found personally, as well as in your historical work, The changing nature of students themselves, demographic change in terms of mix of gender, mix of race, mix of all of those kinds of things? Is that something you've looked at?
David Kaiser: It is. It is. It's something I, again, historically, I've been very interested in. I've written some about in some of my work mostly in the US context.
There were a series of to put it nicest, let's say missed opportunities. I'd say flagrantly thrown away opportunities. Where, the demographic composition of a field like physics in a place like the United States has not stayed still, it's changed a lot more slowly than I think many of us would have hoped but also it's not been in one direction.
Like much of the US labor force, there was a huge uptick in, for example, women studying physics in the United States, during the Second World War. Partly because more men were drafted and so on there and partly because there was recognition that in ‘Total War’ we need all the trained experts we can get; it was seen as a kind of patriotic national security priority.
And then just as rapidly and just frankly, as crushingly and needlessly, those trends were reversed by the late 1940s and 1950s. And that's just clear as day.
I was actually surprised even when, even with my cynical self, going back to see how members of the field, again, in this case, mostly physics in the United States, thought about gender and not just sort of demographics, not just male, female, but feminine, masculine.
What did they think was the appropriate identity or personae for a young researcher? It wasn't just overwhelmingly masculinised, but it was just horribly belittling and misogynist in ways that I'm sure if we could build a time capsule and interrogate them, I'd like to think they'd walk that back.
But you can find this in things like faculty skits or grad student skits in various departments. A little moment of levity and, boy, are those time capsules for expectations and mores. Jokes can be very historically and culturally revealing. What even counts as funny.
At one of these schools in approximately 1960, one of the skits was, 'well, we should have more women in physics' and 'here's how we evaluate their admission to graduate program: Have them send photos of them in bathing suits'. That's not even funny. But that was like, crack them up, in 1960. And for men, it was ‘have them send their bank account’. Okay. Ha ha ha. Well, you know.
But that was just seen as like a run of the mill off the cuff humour in a way that I'd like to think, wouldn't even register as anything like funny today.
Again, being immersed in archival holdings of the 1950s for very big prominent departments of physics in the united states, you see job ads come out and they would say things like 'only white, able bodied men need apply'. Why did they even have to say that? I mean, who else did they think were filling the ranks of their schools at the time?
But in some cases, that was literally written in the job ad in a way that, again, thankfully, we don't have that kind of overt barriers. Although, of course, many, many barriers remain.
And one thing, I don't want to be a Pollyanna and say, we've licked it, we're done. But one thing I do take, frankly, special pride in is that right now in my own physics research group, there's more women than men, and there's a very easy sociability in a way that doesn't reflect these horrible kind of, what was seen as joking material in generations ago.
That's not just my group, the department itself, we're not done, and yet it's no longer newsworthy when, you know, another incredibly talented young woman is tenured in the physics department, which is now we have many, many, many, and, and more in the pipeline. But that was still kind of newsworthy in my own living memory, let alone when I go into longer ago sources.
Likewise, for members of underrepresented racial or ethnic groups, likewise for differently abled people, you know, all these things, there's at least an awareness that these things are going to matter and that they don't just kind of addressed on their own. It takes proactive mentorship and resources. It takes priorities and not just good thoughts.
That was a long, maybe overheated answer, but I do think even the recent history helps us show, boy, we better get to work because look at where we're coming from. It's not a place where I think any of us who wanted to, in that instance, be transported back to.
Samara Greenwood: So what value can you see for scientists today, as well as maybe for the general public, that's a big part of our audience, in understanding more about the history of scientific training and pedagogy?
I think it's partly to underscore the overall historian's point about contingency. It needn't be that way.
Now, it doesn't mean we're doing it all wrong - it's somehow constructed so therefore off base. It's constructive. It was made by people in times and places. It was negotiated and that means they are capable of change.
For example, the topic we were just talking about. It doesn't have to remain a certain kind of demographic or personae. That we're capable of changing it and it's up to us to change it.
History among other things can be… I'd like to think it can be empowering because history is about change over time and it reminds us things don't just change on their own. It’s contingent and people have to agree to try to work towards changes. And that's hardly limited to scientific pedagogy, but that's an example.
And then in a more fine grain, what about more let's say, you know, hands on or active learning projects, or even at the really classroom level there's not one way to teach the Schrodinger equation. There's never been one way.
And maybe by sampling some of the smartest teachers we've had over the past, in this case, say, past century, if we think about quantum theory, there's some pretty great things on offer. And we don't have to just do everything that was done in 1935, but we could be surprised, ‘that was actually pretty cool. Why did we forget about that?’ And so as a kind of candy store to go back and shop within, knowing what we know now, having our present and forward oriented goals that there are, I think, practical lessons that we could be inspired by, as well as this broader lesson that we have to make the change we want.
Samara Greenwood: No, fabulous. Final question for today. I wanted to ask what areas in history of science do you believe are perhaps understudied and would like to see further research?
David Kaiser: Oh, there's many. I mean, we need many more historians of science, many, many, many.
We as a community still tend to be focusing on North America, Western Europe, or cognate places. And so, I think comparative, transnational, getting back to something like a longue durée, and coming back to something we talked about before, that needn't be only up to individual savants. A few sterling members of our field can write brilliantly and seemingly effortlessly across practically millennium. I'm not one of them.
But what if a bunch of us teamed up more often, right? And tried to really tease apart, not just in a kind of superficial way, the compare and contrast work to talk about really longer arcs of human experience - of places in the world where something like the disciplined study of nature has been unfolding in ways that really might show more difference and similarity to the better known examples.
I think there's a lot of opportunity for expansiveness in how we cast our questions and the sources in which we seek those answers.
Samara Greenwood: Oh, fabulous. That's an excellent way to finish the podcast. So I wanted to thank you so much, David, for coming on the podcast.
I have absolutely loved talking to you and there's so much there that I think everyone can take something away.
David Kaiser: Well, I really appreciate it. Thanks so much for having me on. It was a real treat. Thank you.
For more on the history of physics, check out David Kaiser's Open Access Course: Einstein, Oppenheimer, Feynman: Physics in the 20th Century | Science, Technology, and Society | MIT OpenCourseWare