Norman Wagner

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ORAL HISTORIES

Credit: University of Delaware

Interviewed by
David Zierler
Interview date
Location
Video conference
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In footnotes or endnotes please cite AIP interviews like this:

Interview of Norman Wagner by David Zierler on May 26, 2020,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
www.aip.org/history-programs/niels-bohr-library/oral-histories/46750

For multiple citations, "AIP" is the preferred abbreviation for the location.

In this interview, David Zierler, Oral Historian for AIP, interviews Norman Wagner, Unidel Robert L. Pigford Chair in Chemical and Biomolecular Engineering at the University of Delaware. Wagner recounts his childhood in Pennsylvania and his undergraduate experience at Carnegie Mellon and his decision to study chemical engineering at Princeton. He discusses his graduate research at Los Alamos and Sandia and his postdoctoral research in Germany.  The bulk of the interview covers Wagner’s wide-ranging research agenda at the University of Delaware.  He discusses his strategic partnership with the NIST Center for Neutron Research, and the range of commercial endeavors that he has been involved in as a result of his research in soft matter physics. Wagner explains his work in biomedical engineering, and his collaboration with NASA on Mars-related research.  At the end of the interview, Wagner provides a broad-based explanation of rheology and its development as a distinct scientific field.

Transcript

Zierler:

This is David Zierler, oral historian for the American Institute of Physics. It is May 26th, 2020. It's my great pleasure to be here with Professor Norman Wagner. Norm, thank you so much for being with me today.

Wagner:

My pleasure, David.

Zierler:

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

Wagner:

Yes. So I am the Unidel Robert L. Pigford Chair in Chemical and Biomolecular Engineering at the University of Delaware.

Zierler:

What does the word "Unidel" mean? Is that just University of Delaware?

Wagner:

It's a foundation that was established to support scholarship at the university, so it's a private foundation. And they endow a number of professorships, or partially endow professorships. So the Pigford Fellowship, Bob Pigford was a famous pioneer, one of the earliest chemical engineers in the field, and first chair of our department, and so they established a named chair in his honor partially supported by Unidel, which is the University of Delaware Foundation.

Zierler:

Ah! Now, did the Pigford family itself endow the chair, or this is more an academic honor for Professor Pigford?

Wagner:

It is supported by Bob Pigford and his students and friends, and then topped off, if you will, by the Unidel Foundation.

Zierler:

OK. Very good. So let's now take it back right to the beginning. Tell me about your family background your early childhood.

Wagner:

So I was born in Philadelphia, very close to here actually. Well, my father was a graduate student at the University of Pennsylvania in chemistry, but then we moved back to Western New York and Western Pennsylvania, and, ultimately, I went to high school in Pittsburgh. And so I grew up in a chemistry-friendly family. My mother was an English teacher, and 20 years of public school teaching high school English. And my father, for a while, taught, and then he went to a work for a company called Calgon Carbon in the Pittsburgh area, and that's where I went to high school, and then, ultimately, went to college at Carnegie Mellon.

Zierler:

What was your father's academic area of expertise?

Wagner:

He worked, actually, interestingly—he was in the field of catalysis, but, as part of my recollection of him getting his PhD, ultimately, from the University of Buffalo, he was working, in part, on analyzing some of the moon rocks. And that had a big influence on me as a child growing up, of course, growing up at the time of the Apollo moon landings and the Apollo program as a young child. And then having your father actually working—and I got to see moon rocks for the first time, him taking me to the university and showing me what was this dust, which is not that impressive to a 7-year-old kid other than the fact that it came from the moon, right?

Zierler:

Right, right.

Wagner:

So that's one of those moments where you're—anticlimactic. I'm expecting the rock to glow in the dark or something as a kid.

Zierler:

So your father very much involved you in his scientific endeavors? 

Wagner:

Yeah, yeah. He was that. And my family was very much coming from blue-collar roots. My one grandfather was a machinist on my father's side, and the other side my other grandfather worked in the steel mills and on the railroad. So attending college and education for my parents was a big deal. And then, of course, the grandkids were expected also to go to college, especially for one of my grandmothers, who had to drop out of school in 8th grade to take care of the family because her mother had passed away, she reminded me every day when I complained about any homework or anything, she said, "I didn't get to go to school. You're going." [laugh]

Zierler:

Right.

Wagner:

And so that was pressure, if you will, to become academic right from the beginning.

Zierler:

Now, you mentioned you moved around after your birthplace in Philadelphia. Where would you say you spent your formative years growing up?

Wagner:

I think, from a perspective of growing up in Buffalo, and then a small town in Northwest Pennsylvania, and then in the suburbs of Pittsburgh, very different experiences. One a big city, one a very rural town, and another in the suburbs, gave me, I think, a very panoramic view of American society, if you will, although that's all Western Pennsylvania, Western New York culture. But it was interesting to have all of those experiences growing up. But I certainly went to a public high school in the South Hills of Pittsburgh, Upper St. Clair, which was a phenomenally good high school and had a number of things. One, it had a lot of German immigrant students whose parents came to work for a company called Bayer—well, Miles Lab which was actually part of Bayer. And so we had a lot of very good German friends who played soccer really well, much better than I could, who came for a couple of years and did their high school there. And the other was we had an excellent chemistry teacher, who has passed away, but was really influential. As most people who work in chemical engineering will tell you, it's often the high school AP chemistry teacher who—

Zierler:

I've heard that, yeah.

Wagner:

—inspired them. And, obviously, I came from a family of chemists, PhD physical chemist as a father, but the chemistry teacher was also very influential in engendering, if you will, a curiosity about, in general, natural science.

Zierler:

Mm-hmm. So when you were thinking about applying to college, were you thinking about specific programs that you wanted to work in, like chemistry programs, for example?

Wagner:

Yeah. Chemistry interested me a lot, but I got interested in how to apply it, more application oriented. So a natural place for me to go was chemical engineering.

Zierler:

OK.

Wagner:

And, of course, there's a really good chemical engineering program in Pittsburgh. I was very lucky to be able to go to Carnegie Mellon, and that was a good fit for me, and I enjoyed it very much. And one of the hallmarks of Carnegie Mellon that was really important for me was the ability to do undergraduate research, because I also was partially working towards earning money for college in that. And so I worked part-time in the laboratories of Professor Edmond Ko which, interestingly enough, was a catalysis laboratory. But, from my freshman year on, I was already working heavily at the university in research and ended up publishing four papers as an undergraduate. Obviously, I was a coauthor, but I got to work with some phenomenally good not only faculty, but master students and PhD students in that laboratory who we've stayed in touch with to this day. And that was really a big part of my getting interesting in a career in research, going to graduate school and that, because it became obvious to me that I really enjoyed this.

Zierler:

Now, looking at the trajectory of your father's career, who had appointments both in academia and in industry, I wonder if that was formative for you in terms of thinking about various options coming out of undergraduate? Because chemical engineering, obviously, is quite applicable to industry, if that was something that you wanted to pursue.

Wagner:

Absolutely. And, when I entered college, I didn't really—you're 18 and you're thinking about what you want to do with your life. Graduate school four years from now, that would've been an infinitely far-away choice.

Zierler:

Yeah.

Wagner:

And it wasn’t really on my radar screen, but it was really when I got to work in this laboratory as an undergraduate that I saw what the graduate students were doing and the interesting problems they were working on. And the close interaction—I was very lucky—the late Ed Ko, who was the faculty member who had that laboratory, he was a phenomenally good mentor. A little anecdotal story that you'll enjoy: So, on my father's side, as I mentioned, my grandfather was a machinist, so I was always tinkering and doing things, and my father was always working on cars and stuff when you could still do things like that with cars, you know, still repair them with normal tools. And so I was involved, as a kid, always in things like that, right? Building, house construction, I learned to do plumbing and electrical work and roofing, and how to repair brakes and all that stuff growing up. And I was very hands-on. And so that background of seeing my grandfather have his own machine shop at his house and all that. So, when I got to work in Ed's lab, there was a summer—and I was sort of alone for a while, or not totally alone, but the grad students were busy with their writing and stuff. And I was given a task to do something, and there was a piece of equipment that measured surface absorption. Details aren't that important, but it was leaking. And because it was leaking air, it wouldn't function properly. And I, of course, naturally just got a bunch of tools and took it apart. And I'll never forget, Professor Ko was away for two weeks, and when he came back, he asked me what I was doing, and I showed him his beautiful instrument was in pieces on the lab bench.

Zierler:

[laugh]

Wagner:

And, to his credit—I must give him a lot of credit—he was clearly upset, but he didn't say anything. He just sort of walked out of the lab and said, "OK." And he just let me go. And I put it back together and I leak-checked it and it worked. And I took my data. And so then I had a meeting with him, and he looked at me and he said—I showed him the data and it was good—he looked very relieved. And he had to sort of tell me, he said, "Look, please don't ever do that again." [laugh]

Zierler:

[laugh]

Wagner:

But for me, growing up hands-on, if something was broken, I just fixed it.

Zierler:

Yeah.

Wagner:

It didn't occur to me that I shouldn’t take apart the—I had no idea the value of the instrument was thousands of dollars.

Zierler:

Right.

Wagner:

And it really should have been done by a professional, but to me it was like, oh, it's plumbing, I can fix this.

Zierler:

Yeah.

Wagner:

But, to his credit, instead of firing me on the spot and kicking me out of his lab, he just let me—and he didn't say anything. He just walked away. And I just put it back together and took the data, and it worked fine, so luckily for all of us.

Zierler:

What were some of the broader research questions that Ed was working on in those days?

Wagner:

Yeah. It was an interesting area, and this is how I ended up in the field I'm in now, because we were looking at what are called supported metal catalysts, and these are materials that are—we have nanoparticles supported on another surface of something so that you can handle them and use them as energy and as catalysts. And there was thought to be some interesting special reaction sites, very high reactivity or very selective, due to the fact that particular metals and particular support oxide materials had interactions right where they met. And so it was very nano-oriented questions he was asking, and they were very controversial. So it was a really good experience for me in many ways, but one of them was that there were groups around the world who said, you're absolutely wrong in your thinking, to him and his group. And there are different camps out there arguing about this effect and where it came from and what the molecular level, atomic level reasons were. And I was just an undergraduate working in the lab doing experiments under the guidance of the masters and PhD students, but it was really insightful because I would hear about—we would talk and I would hear about and I'd see—eventually, I got to go to a scientific conference with him, American Chemical Society meeting in Philadelphia, and I'll never forget people attacking and saying, oh, this is wrong, this can't be the right idea. And it was really interesting to see that science was not just, well, what you read in the books. It was always—there was an answer. You have a question and an answer, hypothesis answer, you move forward. Here there were people arguing and coming with data from different camps and simulation of different experiments and different groups saying, no, you're wrong, you're right. And so science got to be much more interesting. It wasn't just linear, like the textbooks showed you. It was now real world, and people's livelihoods, egos were at stake, and there was a lot more going on there.

Zierler:

And if you could explain about catalysis; what are some of the most interesting academic questions and industrial applications surrounding it?

Wagner:

Yeah. So I've been out of the field for a long time, David. So anything I tell you now will be dated.

Zierler:

Sure.

Wagner:

But all I could tell you back then was that we were really trying to—one of the problems I ended up working on for a summer was really trying to convert methane into more useful chemicals, so upgrading, if you will, methane to higher hydrocarbons, 'cause we were producing a lot of methane. And Pittsburgh is a big coal area.

Zierler:

Right, right.

Wagner:

So you had a large Department of Energy lab and I worked there one summer at the federal government. And the project I had was really looking at ways that we could, using zeolites, react methane in to upgrade it, if you will, to more valuable things for the petrochemical industry. And so a lot of the catalysis at the time was really—we had an oil crisis, we had an energy crisis. We were running out of oil back in the—this is the 1980s. So we were running out of oil, the world was going to end, and we were looking at ways of taking coal and liquifying it, but you were making a lot of methane. At the time, we didn't realize how dangerous the methane was, I think in terms of a global warming perspective.

Zierler:

Yeah.

Wagner:

But there was still a lot of interest in recovering that methane and using it for something other than just burning it, which would've been a good thing. So these were the kinds of questions we were trying to work on understanding. But not just from, like, a shake and bake and make something, but really from a molecular viewpoint, from a molecular chemistry viewpoint, of how do we take this molecule, break these bonds, insert other oxygen or other carbon bonds, and move forward. And it was done at a really atom-by-atom kind of thinking, which was, I think, the early stages of molecular view of catalysis that's now very prevalent with simulations and things. We didn't have all of the tools back then to really do all of that from a computational standpoint, and we didn't always have all of the investigative tools that you have now at the molecular level, but we were certainly thinking about it from a molecular atomistic viewpoint, not just saying, well, if I mix this black arts stuff, mix this together, shake it up, maybe it'll work, right? No. We were trying to design things really at the atomistic level without the tools that you have now to do that.

Zierler:

Now, I'm curious. At what point, if you can remember, did you commit to pursuing a graduate degree straight away upon completing your undergraduate?

Wagner:

Yeah. It was an interesting call. So, like I said, I was working in catalysis and I was making these nanoparticles. And so I decided to take a class by a professor by the name of Geoffrey Parfitt, who is a classical English professor, exquisite in his teaching, somewhat arrogant, but had a right to be. And he was working not in catalysis but in surface science and colloid and interface science from a more material standpoint. And, since I was making the nanoparticles, I thought, well, let's learn more about this field because I'm making these things, these colloids and nanoparticles. And so that's where I really got interested in that field, because what I saw that was missing in catalysis was we didn't have the mathematical engineering framework in catalysis at the molecular level or driving at the molecular level yet, but what I saw in the field of colloid and interface science was really beautiful classical physics and mathematics in that field that goes all the way back to Albert Einstein. Einstein's viscosity coefficient is one of the classic papers in the field from the early 1900s. So, right at the atomistic age of science, colloid and interface science was very important in this field. And I saw an opportunity there to really move from being just experimental to really looking more into engineering mechanics and fluid mechanics and deep physical principles in theory and mathematics that were very elegantly laid out already in that field. So there was a lot to be done still, but there was this enormous basis that went way back to the early 1900s, like I said. And I was fascinated by the fact that one could use this higher level of mathematics and physics to really make predications and solve problems in a way that we really couldn't do at a molecular level in catalysis at that time. And I think that's changed to some extent. So that's where I got interested in colloid and interface science, and, of course, that's what took me to rheology, which is ultimately what we probably want to talk more about in terms of that.

Zierler:

Now, what graduate programs did you apply to?

Wagner:

So I applied to a bunch, but, I'll tell you, everywhere I went, when I talked to people—like I'd go to Berkeley or Stanford or Minnesota—I would run into people who had strong connections to Carnegie Mellon in the field of colloid and interface science. And they were fantastic faculty and they had wonderful programs, but many of them would say—when I told them what I was interested in, they said, you should go look at Bill Russel at Princeton.

Zierler:

Yeah.

Wagner:

You should go talk to Bill Russel at Princeton. And so I went to Princeton for the graduate visit, and Bill Russel wasn't there. He was on sabbatical. But I talked to other faculty there, Dudley Saville, Bill Schowalter, Bob Prud'homme and others who were working in this. There was a really phenomenal group there, I would say. At the time, they were writing their classic book, Colloidal Dispersions, Saville, Schowalter, and Russel. And so they were writing that book as I became a student there, they were working on it. And it was an exciting time and place. It was the right place to be at the right time in history to work on this problem. And so I decided I really wanted to go to Princeton and work with Bill Russel, even though I'd never met him until I got there to graduate school.

Zierler:

What was this mythical-level draw to Bill Russel that you were hearing all over the country?

Wagner:

Well, when I explained to people I was interested in taking statistical physics and working on this problem, he was really driving—he had worked with Andy Acrivos and this long chain of students of Acrivos, and he was really pioneering an approach that built off of a physics approach that's classic in the field of—it's by Marian von Smoluchowski. And he was taking that and moving it into a many-body problem. So he was taking what we had been able to do in the 1900s, and really in the late 1980s, and so he was pushing it into the many-body problems. There was a group in Cambridge, too, which he had a postdoc with that was working on that, as well. And so it was a combination of fluid mechanics and statistical physics in a way that very few people were doing in the world, and at a very high level. And people knew about it and they were excited about it. And so I went from an experimentalist to becoming a theoretician essentially.

Zierler:

Yeah.

Wagner:

Which didn't last forever, by the way, because we had a couple of fun experiences there with that, which I can relay to you, which they're a lot of fun. So Princeton, like all graduate programs to this day in chemical engineering, was brutal the first year. You had a lot of classes to pass, you had qualifying exams, so you didn't get to do much research because you were just struggling with the coursework at a very high level. But, anyway, so at the end of the qualifying exams and the end of my spring, I was so fed up with school and graduate school, and an opportunity had arisen at Los Alamos National Lab for a summer intern, a graduate student intern, to go to Los Alamos with a fellow by the name of Alan Graham, who became a very good friend. And Alan had this great idea to do some very simple computer calculations, simple by our means now, but at the time required supercomputers, which now my laptop is probably better than.

Zierler:

Sure. Yeah.

Wagner:

But, anyway, so I got to do high-performance computing at Los Alamos and Sandia with this really great group, and I met people like Howard Brenner from MIT and others who were working with Alan. It was a great opportunity. So I just had to get away from graduate school. But what it afforded me to do was to start my thesis, and, in a quiet way, because, if you've ever been to Los Alamos in the summertime, it's deserted. The coyotes walk through the streets.

Zierler:

Yeah, yeah.

Wagner:

And I was single, and so I had plenty of time to learn more statistical mechanics and start reading the background papers for my advisor. And what I discovered was that the basis of my thesis, which was some beautiful work that was the last chapter of Alice Gast—and so Alice Gast is now the president of Imperial College. And she had laid forward a beautiful foundation and had done some great work with Bill. And they had one paper which was just a part of her thesis, not the most important part, but became the starting point for mine. And I was convinced that, by the time the summer was over, that there was something not right about the final results of that. The theory looked good but there were some questions about it. And so I remember going back to Princeton and walking in Bill's office, and he was a chairman at the time, and saying, "I'm back. Let's get started." And, "I think your paper has some problems with it." [laugh] He looks at me, who is this kid who I've hardly ever met?

Zierler:

Right. Bold move.

Wagner:

But it turns he looked at it—Bill was a fantastic advisor. He looked at it very carefully and he came back, and he said, "There's clearly some issues here." We made some approximations that we didn't know we had made. [laugh] And he pointed them out. Let's see what happens. So the first part of my thesis really became looking at what other approximations that could be made. So Alice and Bill had made an approximation unknowingly, basically, and mathematically, and then I just looked at it and said, oh, well, you don't have to do that. You could try other things. And so we tried other things and we got somewhere with it. And it was a lot of fun. But that was an interesting way to start your relationship with your advisor, like, you're wrong. [laugh]

Zierler:

[laugh] Right. Bold move.

Wagner:

Yeah.

Zierler:

I think maybe this is the appropriate time—I want to ask this question: Talking about fluid dynamics and statistical physics, can you talk a little bit about what the discipline of chemical engineering means, in terms of how interdisciplinary it is and how its relevance extends to these areas that you might think, at first glance, might be more at home in a physics department, for example?

Wagner:

Yeah, yeah. It's interesting, because the best definition of chemical engineering I've ever heard is the following, and many people will quote this to you: Chemical engineering is what chemical engineers do.

Zierler:

Right.

Wagner:

And so what I really liked about this discipline is that it—in some places in the world it's technical chemistry. Like, how do you take organic chemistry and make things with it in a big factory? And there's a bit of that. But chemical engineering is statistical mechanics and molecular engineering. So you talk about molecular engineering, and you look at programs that are molecular engineering in the United States, and others that have started in the last decade or two, and it's all started by a bunch of chemical engineers. And so what you realize is that we've always been doing—chemical engineering is, at its heart, at its discipline, the transformation of matter at the molecular level whether by chemical or now biological means. And so that's everything. So to do that you'd need everything. It's kinetics, it's transport, it's thermodynamics, fluid mechanics, statistical mechanics, you name it. And so, yeah, I mean, I took courses in Princeton. I took some classes in the physics department in statistical mechanics. I took statistical mechanics and chemical engineering. And you get a different flavor of the same discipline applied to different problems. So the nice thing about it is it's a discipline that doesn’t seem to have any inherent boundaries where people say, no, you can't do that.

Zierler:

Right.

Wagner:

I've never run into that problem with chemical engineering. And, hence, rheology becomes another area, because it’s a natural. Rheology is transport, fluid mechanics, and materials combined. And so who better to do that than chemical engineers?

Zierler:

There you go.

Wagner:

And that's why you find the majority of rheologists are chemical engineers. Because, again, you need all these different disciplines to come together, usually, whether it's polymers or soft materials or colloids or metals or whatever; rheology of something.

Zierler:

And as a matter of intellectual history, I'm intrigued by your initial foray into being a theoretician. Can you describe a little bit more about why you pursued that, particularly coming from such success as a tinkerer and coming from mechanics in your family?

Wagner:

That's a great question, David. And, again, the discipline of chemical engineering doesn’t require you to say, I'm a theorist or a simulator or an experimentalist, and that's, I think, the strength of our approach. So you can't be everything to everybody. OK. I'll go forward on that. You really have to put in your time to become an expert in something. And so it's hard to do all of these things at a high level at once, but what I've found really, really valuable—I went on to do two theoretical postdocs before I started at Delaware, and I did a heavily experimental program. But I kept some theory going, largely through collaboration with people. But I could do that because I had some credence, I had some ability to say, hey, I've written codes on supercomputers, I've published papers on large-scale molecular dynamics of deformation of metals and stuff, and I've done work with some great theory groups around the world. And so you have some credibility, then, I think when you start to go to people and say, this is an interesting problem; I've got some interesting experiments that I know you can do the theory or the simulation that's required to look at it. So that's where you start collaborating with really great people around the world in many different ways.

Zierler:

Yeah.

Wagner:

And then you're answering research questions at a level that's difficult to do if you only are a theorist or only are an experimentalist with that. I mean, I'm quite aware of the criticism that, to be good at something, you really have to dedicate yourself to it. But I think it's possible in one's career to emphasize one area or another, but you have to cut your teeth in learning the methods, right?

Zierler:

Yeah.

Wagner:

And so I spent most of my graduate school doing theory and I did simulations then, both at the summer position at Los Alamos—then I went back to Los Alamos after I went to Germany to do more theory—then I went back to America to Los Alamos to do more simulation before I started my career at Delaware. So, by the time I started as a young faculty member, I actually had a project in simulation and an experimental project, a couple of graduate students in different parts, and doing very good work. And so I was able to do that because I had built some foundation to be able to do that. It's hard to sustain that, to say I'm going to do all these things all the time, so I don't do that anymore maybe as much, but I'd certainly keep strong collaborations in the parts that I need to plug in the pieces. And, certainly, having some credibility there, I think, helps me collaborate with people because I understand their language and their culture, if you will, of these different parts of our discipline.

Zierler:

Now, starting with that bold origin story of your relationship with Bill Russel, can you talk a little bit about how, from there, you developed your own dissertation topic?

Wagner:

I think I realized pretty quickly when I got—Carnegie Mellon was a great experience and I had great friends and colleagues there. But, when you get to graduate school, you realize there are a lot of smart people, many of them much smarter than you. [laugh] And so I became very good friends with a number of my classmates who were absolutely brilliant, and to this day we're good friends. And we write papers together and do work together. But I was looking at what they were doing, and I would go up to them and I would say, "This is really interesting, and you really understand this much better. Do you mind teaching me about this, and do you mind—you're going off to work in industry maybe as your career for a while—would you mind if I put a graduate student on this problem and work on it?" And so, if you listen to them and take the time to learn from them and are willing to ask, most of the time people are very excited to have you work on their ideas and push them forward. And so we've had some great collaborations over the years where really—what I learned in graduate school is there's a lot of smart people out there, and maybe you're a fool if you don't take advantage of that fact and learn from other people around you. And, I'll be honest with you, to this day, the students I have are remarkable and postdocs are remarkable, along with my colleagues and friends, and I learn from them, as well. I'm very open to listening to their ideas and ideas forward, because many of them are all very bright and working hard.

Zierler:

Another divide to consider, in terms of thinking about dissertation topics, is the extent to which you were interested in pursuing academic research questions and how much were you thinking about, what's really useful? What are things that I can do that actually have useful, real-world applications? I'm curious what your thought process might've been on that kind of a question?

Wagner:

That's a good question. So, when I was finishing graduate school, an academic career was not my first choice in the traditional way. Because, at the time, Bell Labs and like Exxon near Princeton were two of the really phenomenal research centers in North America, two extraordinary places.

Zierler:

Right.

Wagner:

And I interviewed at both of them. Unfortunately, I didn't get jobs at either. At Bell Labs they had a hiring freeze. So there was a fellow by the name of Ron Larson, who's now a friend today, and I was really enamored with the research he was doing. And he had phenomenal people working with him, many of whom are faculty at top universities. And so you could argue that he was doing academic research, and the people like that at Bell Labs were doing academic research, but not in a university setting. I had very little interest in—well, I don't want to say little, but I didn't have strong interest in teaching right away. I was interested in the research, and I thought I could best do that in a corporate-like lab. And when those didn't pan out, I had an opportunity through the National Science Foundation to go—I got a fellowship for a postdoc, and they were called NATO fellowships at the time, and you had to go to a NATO country, and Germany was interesting to me. And so I had read a paper—this was back in the day when everything was in the library. I'd go to the library and I would read—religiously every Friday morning I'd go to the library and read all the new journals. And I read this phenomenal review article which I couldn't understand. It was written by a German group in Konstanz, Hess and Klein, Rudolf Klein and his postdoc at the time, Walter Hess, and they wrote a phenomenal review article. It was like 100 pages long. It had mathematics I'd never seen before and it had theories I'd never played with before but had heard about. And I remember browsing this article, and I remember taking it to my advisor, Bill Russel, and asking him, and I said, "Is there something to this? Is this really something interesting?" And he said, "Oh, yes."

Zierler:

[laugh]

Wagner:

And I said, "Do you know the author, the person in charge of this project, Rudolf Klein, professor in Konstanz?" He said, "Oh, yes, very well." And Klein had been in the United States, it turned out, and worked for RCA for a while before he went back to Switzerland and then took the job in Germany at the University of Konstanz as a professor, and built this really strong group there. So that's where I ended up going for my postdoc. And it, again, was sight unseen, and it was all based on this paper I had picked up in the recent journal, I think it was Physica A or something and on statistical mechanics, and I thought this was brilliant. So I wrote him a letter and said, "Could I come to work for you, have a fellowship?" And the answer was yes, and so, had gotten on a plane and went to Germany and eventually met him. [laugh] So it was a lot of fun, but that was, again, kind of like a—I wanted to learn this theory because it was the cutting edge, and I figured if I'm going to work in this field, I need to do that. Luckily, at just about that time is when I got my job offer at Delaware interviewing—I had come back from Germany to interview, and so that year turned out to be a very good year for me. I also met my wife there. At the time, she was a student there, as well. So it was an interesting year. And just by fate I just had read this article and thought it was brilliant.

Zierler:

Now, what was your relationship with Los Alamos during these intervening years?

Wagner:

It was really good. Los Alamos, the first time I was there in 1985, was really one of the most remarkable—it's still a phenomenal place, but it really was a remarkable place at the time. And it basically had unlimited capabilities. So, like, 10% of the whole world's computing power was in one room there that I saw.

Zierler:

Right.

Wagner:

And it's a very impressive place. But they had the best of everything, and money didn't matter.

Zierler:

Yeah.

Wagner:

I mean, the science there was being done at a very high level with things that I'd never imagined existed at levels that I'd never seen before. And so it was really an eye-opening experience to see big science. And, to this day, I work very heavily with—I have a group at the national lab nearby here at NIST. And national labs are incredible resources. They have things that—I do a lot of neutron scattering now, and that requires a 100 million- to billion-dollar facilities and instruments that are 10s of millions to 20 million dollars, like the one we're building now. And this is just the scale that you just don't do in a normal academic lab. This is national lab scale. So Los Alamos was an eye-opening experience, and it really gave me, if you will, a feeling that you can really do big things in science. When you've got a lot of people and a lot of resources dedicated to something, you can really achieve things that an individual researcher could never even imagine existed. The resources that the national labs have, especially at Los Alamos at that time, was just unbounded.

Zierler:

And I'm curious, based on that, if you ever thought about pursuing a career within one of the national labs?

Wagner:

Yeah. Well, like I said, I run a center now for neutron science at the University of Delaware, which is a cooperative agreement with NIST Center for Neutron Research nearby in Gaithersburg, Maryland. And I actually have students, postdocs, computer scientists, and people actually who work for our center, of which I'm the director of, are University of Delaware employees but physically located in the national lab. So we had a strong collaboration with NIST. And we're, like I said, building new instruments there on the scale of 10-million-dollar type projects that I'm leading. And it's just so—I've, in a way, got the best of both worlds.

Zierler:

Yeah.

Wagner:

Essentially have a group at the national lab but I'm at the university, and there's strengths on both sides. But have many good collaborators and colleagues and friends at the national lab, and it's certainly been an enormous resource for my students and others at the University of Delaware working with NIST at the national lab. And, before that, I had done a lot also with Los Alamos, even after I started at Delaware, we kept strong collaborations for many years.

Zierler:

Now, coming back to the idea that the original plan was for you not to pursue an academic appointment, I'm curious if that had changed and then that's what led to Delaware, or you were sort of recruited and that's how that turned out?

Wagner:

Interestingly, at the time, some of the best science was being done in industrial labs. So I had an opportunity to go to IBM in Almaden and DuPont and then Delaware. And, in the end, when I looked around, Delaware and DuPont are like connected at the hip at the time. We're right next to each other. And it became obvious to me that I could essentially have the best of both worlds [laugh]—

Zierler:

Yeah.

Wagner:

—by going to a place—really strong chemical engineering program in the University of Delaware, which had phenomenal people at it that I really wanted to get to know better. At the time, Art Metzner, very famous rheologist, and people like that. And I thought, I've had great opportunities to work for really great people all my life, why not work with someone like that as a young facility member, him a senior colleague. And that was phenomenal. And, yet, I've got DuPont right around the corner. And what was obvious to me was, already as graduate student, I had done some work with Bill Russel, he had worked with Rohm and Haas and DuPont very heavily, and I'd done some projects with scientists from there just because I had some expertise and I could help them out in the group. And so I got a little taste of industrial research. Plus, Bill was part of something which still exists, a very strong organization called the International Fine Particle Research Institute, which is a consortium of industries that's global that deal with fine particles, colloids and that. And so I got kind of an early introduction to how industry research worked. And I remember I said my first interviews were with Exxon Research and Bell Labs, and so going to the university at that point made a lot of sense to me, because I said, I can try it. And I always had the idea in the back of my mind that if I really didn't work out at the university, there were these great research laboratories to go work for. Well, interestingly enough, the world has changed. Those research labs really don't exist in the same way they did back then, and, if you will, a lot of the fundamental research has now moved more and more into the university.

Zierler:

Right.

Wagner:

A good choice, I feel.

Zierler:

Yeah.

Wagner:

But DuPont was very important for me. At Delaware, I learned very quickly from my senior colleagues, including Art Metzner, that, for every academic scientist, there's 10 like us doing similar work in industry, but they're not publishing and they're not going to conferences so much. They don't get that choice. But if you talk to them, they're smart and they've got good ideas.

Zierler:

Yeah.

Wagner:

And so, here again, if you're willing to listen to people and build collaborations with them, then they're excited that someone in academia might work on the problem, and we would find money either from the company or some collaboration with some federal or state money, or write an NSF grant together, whatever. And we would find a way to fund the work and publish the results. And, occasionally, it got more interesting. We'd patent or do something, and the company would benefit. But, if nothing else, there were really good questions coming out of the industrial environment because, again, there are just so many more people, and they're dealing with real problems. They're dealing not with esoteric things, they're dealing with real-world problems they have to solve. And they see science we don't know.

Zierler:

Right.

Wagner:

They have science questions and we don't have answers for them. And they say, this is actually a good science question, but I don't have the time to work on it and my company's not gonna fund a lot of work on it, but they might fund a grad student to play with it for a while and come up with some ideas.

Zierler:

Norm, I'm curious about your sense of the research environment at DuPont. You hear about, in previous decades, the '60s and the '70s, the way a place—like at Bell Labs, it was really celebrated as a place to do—

Wagner:

Yeah.

Zierler:

—basic science that may or may not have been connected to sort of bottom-line considerations in support of the corporation. Was your sense at DuPont that it had that similar kind of environment, at least in the 1980s?

Wagner:

Oh, it's probably one of the premier places on the globe. The central research at DuPont must have generated a couple thousand patents a year.

Zierler:

Uh-huh.

Wagner:

And most of these ideas ended up being just patents that the company might license and not develop. It spun out a lot of companies, a lot of brilliant people, as with all of the organizations I mentioned, many of them, when they left there when they saw that maybe the future wasn't so rosy there as like it had been in the past, they left and went to really good academic institutions and are now colleagues. So, yeah, the environment was phenomenal. And the advantage that they had was that they could work on problems that were maybe three-year-duration-type problems, which in development work is not possible. Time horizons become months. But they were looking at problems over almost a graduate student lifetime. And so it meshed well with academic research, because we could get money for a couple of years to work on our problem and the company would sustain that, they would allow that. They wouldn't say, oh, you have to deliver a one-year solution. They would look at it as this is an idea that may or may not pan out. And they were willing to take risks, so it wasn’t as if everything that the scientists at DuPont do had to be successful. It was not development work. It wasn't like you have to solve this problem, otherwise the factory closes. It was more like, can we generate new ideas, can we do more blue-sky work that'll be the future of the company?

And DuPont has a long legacy of doing that, investing 5-, 10-year-long research programs to develop a new technology and bring it forward. Think about nylon and everything that came from there, Kevlar, Tyvek, all these things were long-development lead times. And so the culture and the company meshed well with the university kind of timelines and a graduate student lifetime, so it was—and, of course, they're hiring the students a lot of times. And I was doing consulting, as well, on things that were appropriate for students to be working on that were more close to the business. And then, of course, there's a technology transfer back in the company when you develop new experiments or new ideas or new materials, some of that gets patented. Some of it just gets transferred back in and used internally, and we saw a lot of that, too. So very proud of that. That doesn't always show up as a publication or a patent or something, it's just you know it's being used and people benefit from it, or they hire the student and the student continues to work inside the company that we were doing at the university.

Zierler:

So I'm curious, Norm, when you got to Delaware, at this point you already have your hand in so many different research areas, how do you go about establishing a research agenda? You know, these are the kinds of projects I'm gonna work on; these are the kinds of graduate students that I want to accept; these are the kinds of courses that I want to teach. How do you go about sort of putting all of that together given how interdisciplinary both the department is and your own range of interests are?

Wagner:

Oh, that's a really good question, David. I think, in your process of maturing, along the way you're always focused on what's right in front of your nose. You're a grad student, you gotta do this, you're a postdoc, you gotta do this—

Zierler:

But in front of your nose, you have so many things already.

Wagner:

Yeah. What helped me a lot was when I went to Europe. That was an eye-opening experience to be a postdoc in Europe. But there are some differences in research culture, in Germany especially, extremely rich, long tradition of high-level research. And I was in one of the best physics departments there working with someone who's nontraditional German, because he had come from industry and become a professor in theory in Europe, and very well respected. But I remember talking to him about his research program and realizing that he was looking at things on not a grant cycle of two, three years or four years, or a graduate student lifetime of four or five years, he was looking at things on a decade to two-decade kind of level. He was thinking out, you know, 20 years from now, I'm going to solve this problem, not I'm going to solve this problem with this student in the next year. And it was refreshing in a way to see that, even if the grant cycles and the students come and go and the postdocs, there was a continuity of research in there that was constantly building and moving towards a higher level of science. Everybody was building towards something. It wasn't like, oh, I gotta do this, some job. So I worked on many problems over the years, but there's underlying themes to those problems that are essentially being tackled again and again and again.

I mean, I could give you an example for—in my graduate work, my thesis at Princeton with Bill Russel, I was working on hard-sphere rheology and we had some questions about where does the viscosity diverge and how do you predict the viscosity and et cetera, et cetera. And 25 years almost to the day after I finished my thesis, I still published a paper on this topic with Bill Russel together! [laugh] And I tell my current students, I was, like, "Don't be so worried. Maybe a few years after you graduate, we'll finish the last paper from your thesis." I said, "It took me 25 years to finish that last paper."

Zierler:

Right.

Wagner:

And it really was true. It really was exactly the topic of my thesis. Twenty-five years later we had learned more, and we went back and rethought about it and published a paper together on it. So there's continuity there, even though there's many different problems and different things in the soft matter, complex fluids working is very rich, and there are lots of applications. But the underlying scientific questions and themes, and the methods by which we're going to solve them are things I've been developing continuously for the last 30 years here at the University of Delaware. And I may be applying them to different problems or finding different sources of funding that are willing to pay for the work. Sometimes that's the art. But we continue essentially the same ideas that I started working on as a graduate student. In a way, that might sound depressing, but in another way it's not because another example of that is, one is very proud, of course, of your own students, and some of them become faculty and they have their own students. And so we're down to the great-grandchildren now who come out of this program at Delaware. And some of them are still working exactly in this area, applying it to new and interesting problems, but using the same tools and theory, just at a higher level, of course, than we were working on before. And so it spans many generations of academics. So that tells me the questions and methods have some value because people continue to come back to them and use them to solve new and interesting problems. So, in much the same way I saw in Germany, people were thinking about, where does science need to be 20 years from now, and how are we going to get there? And, no, we're not going to get there in three years of an NSF grant or something. That's just the step towards a bigger idea.

Zierler:

Now, when did your affiliation begin with the Center for Molecular & Engineering Thermodynamics?

Wagner:

Yeah. That was interesting—the world, when I started as an academician, was very different than the world now. It was very strongly single PI oriented.

Zierler:

Uh-huh.

Wagner:

So I was given the advice as a young faculty member, you gotta get your own grants, you gotta have your own students, you gotta do your own research. You can collaborate with people, but you have to clearly be able to distinguish what you did. But that was a time in history, too, when one NSF grant would support two or three students, not like now.

Zierler:

Right.

Wagner:

So it was, in a way, easier. You didn't have to spend all your time—I mean, you still had to spend a lot of time getting funding, but a couple of grants would fund your lab, as opposed to now where you might get one grant, one student. So you have to collaborate. So, at the time, it was all single PI investigator, so I was already working with the people when they formed the center at Delaware. But they wouldn't let me join because I didn't have tenure yet, so they told me, they said, you can work with us but you can't be an official member of the center until you get tenure because you have to cut your own path forward. And that was the thinking back then. When I became a department chair many years later, of course, the world was very different. And my advice to the younger faculty was very different. It was, like, you need to plug your research into larger centers. And you still have to have your own individual talents, skills, and get your own grants, but you're never gonna survive that way. I was able to do it, but you're not able to do it now because the world's changed. You need to collaborate. The funding is largely in collaborative groups and centers, and you need to find a home where you can do your work but as part of a larger group. And so the world has evolved tremendously, so that center sort of morphed into a new center on complex fluids.

And then, about 15 years ago, a little over 12 years ago, we started the Center for Neutron Science, myself and Eric Kaler, which is this large collaboration on neutron scattering, which is the natural inclination for, you know, what's a chemical engineer doing in neutron scattering? Well, that was the insight that people at Delaware had to hire myself and a more senior colleague who was an associate professor at the time, Eric Kaler. Now, Eric Kaler has gone on to a stellar career. He's president of the University of Minnesota and just stepped down from that, back on the faculty, a year ago. But Eric and I came in at the same time, he at a higher level than me, higher rank, but we both were using neutrons as a new experimental technique. And, of course, we had this wonderful center nearby in Gaithersburg, Maryland, 100 miles away. And that became a phenomenal opening to characterize materials at a molecular level. So we're getting back to the molecular science of chemical engineering, how do we look at the nanoscale, what tools do we have? Neutron scattering becomes the tool of choice, if you will, for this discipline, and combine it with rheology and, all of the sudden, you've got some tool set that very few people on the planet have. And it gives you a huge advantage, really, to being able to do experiments in a way that you can look at molecular structure and rheological properties at the same time in a way that no one else could do. So that center that we founded on neutron scattering just came out of the Center for Molecular and Engineering Thermodynamics in a way, working with NIST to build this neutron scattering center really became a very formidable research opportunity for us to really push forward at Delaware.

Zierler:

I'm curious how the center served as a platform for collaboration and amplifying your research, as opposed to simply calling up colleagues whose work you're interested in and saying, "Do you want to work on this?" What is it about the infrastructure of the center that helps along all of the productivity that results from these collaborations?

Wagner:

Yeah. This is an interesting center because it's very much a—it's called a cooperative agreement with this neutron scattering group at NIST. You got to realize, NIST is one of the premier places on the planet for especially soft matter polymer science, I mean, for many things. But in this discipline of rheology, there are Nobel Prizes that come out of there regularly. And that place just had giants in the field. And the field of rheology really had—some of the founders really were coming out of NIST, and the earliest meeting was run by the—the first rheology meeting was run out of NIST, the National Bureau of Standards at the time. People were trying to develop the standards for rheological materials. And so the science was there, and you have this huge infrastructure that you could never—no industry or no university could replicate. Tools of scientific discovery that require something like United States government to build. And so you have access to that, but you have access to the people. This phenomenal group of scientists who were really focused on solving these problems that are very deep molecular atomistic level, and they've got tools to do it, and there are theorists there. It's a huge laboratory. And they have a sense of purpose. And so the university then provides an outlet for them, where there are students that often go there to become the scientists and postdocs; collaborations, ideas, connections to industry.

So we have these strong connections to industry. Industry was using these facilities, but it's difficult. But they found it was really good to work with the university and then use the facilities. So we would have postdocs funded by DuPont and other places to do research at the national lab using their facilities, but through the university, which made it an easy way for the industry to collaborate and do things where they just didn't have the resources to spend, to have so many people, experts in this technique. They could work with a postdoc and or a faculty member. So it became an interesting public/private/federal partnership. So you've got the university, you've got private industry, and you've got the federal government all working together to solve interesting science problems. And that's somewhat unique. And so that Center for Neutron Science at Delaware I think really fulfills sort of a vision that people have of solving these science problems using the resources of the federal government; the creative juices and talent you get out of a university system coming in, young people; and established research centers around the globe that are industrial who have real meaningful problems they want to solve. Whether it's in medical things, in terms of monoclonal antibodies we work on, all the way to processing plastics and nanocomposites and things like that, so a broad range of interesting problems.

Zierler:

I'm curious, I mean, to state the obvious, so many of your research interests have commercial applications. Can you talk a little bit about the various legal and ethical and academic issues that you come across when you think about ways of sharing this research so that it is scalable, it is something that can reach market, and yet your affiliation is with the university, not a corporation. How do you identify first those research endeavors that do have commercial viability, and then once you realize they do, how do you navigate all of the considerations between both your own responsibilities and your interest to provide things that are of social value?

Wagner:

That's a great question, David. And I think that's something that has evolved also in the 30 years of my career here at the university in a very interesting way. So let me preface that a little bit. Most of the work that we do is just open, publishable research. But, every now and then, you get an idea, mostly through consulting, that something you're working on has some interesting value. And, for a long time, I didn't really pay much attention to that and we would patent things and we had some work, even in Germany with BASF we patented some stuff. Interesting, but for me it was more interesting just to see that some things might get used at some level, maybe not directly, but somehow you had an impact on a program in industry and it made a difference. That's satisfying. When I was department chair, one of the things I got interested in was the engineering discipline of product engineering. And, at the time, we had developed some patents on these shear thickening fluids that were body-armor related for the US Army and other things. And I got a little frustrated because what I saw was the tech transfer—and I think this is well known now in the field—but you get university IP but it's at stage zero.

Zierler:

Mm-hmm.

Wagner:

It works in my lab.

Zierler:

Right.

Wagner:

And companies often can't work with that. They need something that's one level further developed. They want to see a product protype that's really about ready to take off and be made into a real product with a short development time, maybe a year or less. And we were putting ideas out there and things that were just nascent and interesting, but not at a point where someone could pick it up and run with it in terms of making some product in a short time. And we kept running into that problem. We'd run into these research programs that would start—we'd get a company to license university property, and I would help consult with them or help the university help them try to develop the technology, and it'd take them more than a year or two, and something would happen. A lot of times, the company would get bought, and research programs would get realigned. And we even were close to commercializing some really interesting technology in medical gloves using the shear thickening fluids. And we were told, oh, the company's been sold. The new people are cutting all research projects that aren't within six months of a product on the market. And we were scheduled to bring a product on the market within the next 12 months. So our project got cut. And I was like, ugh, this is horrible.

Zierler:

Right.

Wagner:

So at the time, too, I became department chair and I was teaching product engineering design at a very high level in the undergraduate level. And it occurred to me, I said, how do we do this? How do we take technology from a university to make it really work, not just be a patent that sits out there that gets licensed and never used? Which is what I was seeing happening with my own ideas. So I started my own company based upon a couple of years in which I—here again, find the smart people, listen to them. So in teaching my classes, what I did is I went out to the alumni, and there are many successful Delaware alumni in chemical engineering, and I said, "Please come back. Help me give a lecture on this topic." I even ran a special course for seniors who were interested in entrepreneurship on that topic, which involved a lecture followed by an evening dinner with the person coming back. And we would just sit down and talk about why were they successful and what—so I learned a lot by just listening to these people who were successful, businesspeople, entrepreneurs, whatever.

And so then I realized that we really did need to take the bull by the horns and take some of this technology and move it closer. Now, there's mechanisms for that now which we use which are quite successful. That's the SBIR/STTR programs of the federal government. But to do that, you have to have a small company. The university can't get a small business grant. So we spun a company out of the university that the university part owns, and with a university developed IP, that then has been very successful. We started with organizations like NASA, the NSF, now the Department of Energy as well, developing ideas that come out of the university using the SBIR program. We've got a number in phase two, a number that are being commercialized. And then we also found industrial sponsors who wanted to work with us directly, like Reebok. We have products on the market with Reebok, very successful line of women's athletic wear that's really developed based on materials that we've developed with Reebok scientists through the university and our company. So, here again, it's a partnership between a small business that's a spin-out of the university and a private industry and working forward, or with federal money with an SBIR type program and then a commercialization partner.

Zierler:

How much do you need to work with, like, IP lawyers to make sure that everything—

Wagner:

Of course.

Zierler:

—is done properly and everybody is getting credited where they should be?

Wagner:

Yeah. Lawyers are really important. I don't have a law degree. I probably would benefit from one.

Zierler:

[laugh]

Wagner:

I know of quiet a few chemical engineers who have gone into corporate law and have gone on to get a law degree. Some have their own law firms and they teach courses, and I listen to them. But Delaware is blessed with very good lawyers, I would say. We're sort of there in corporate law, and so you're right. And one of the things is fairness. So you have to recognize that students aren't here to do work for commercialization, they're here to get educated, right?

Zierler:

Yeah.

Wagner:

That's our mission. And so you have to be careful in compartmentalizing how and where—but postdocs and others, if they know what they're getting into, if they want to do this kind of work and want to learn how small businesses work, that's a perfect opportunity for SBIR/STTR work where you'd get some money coming back to the university to help do some of the work, and companies doing some of the work and other partners. Obviously, the university benefits because it's intellectual properties all being licensed through the university. And whether the university gets rich or not, there are very few that do on their intellectual property, but it's part of the invention—so one of the national academies I'm in is in the National Academy of Inventors. And part of that is really the idea that invention is important. Sort of the idea that necessity is the mother of invention, but inventions matter. And intellectual property and new scientific ideas are not always separate from inventions and creations and discoveries that have commercial benefit. In fact, if we listen to what the public needs, what people need, what would make their life better, often those have deeper underlying scientific questions behind them why we don't have those products, why we don't have those solutions. We're living in the pandemic world right now, and the kinds of science questions that we need to answer about the coronavirus will lead us to the vaccines and the treatments and therapies that we need. But there are science questions that we don't have answers to, and if we have those answers, we can solve the problem. So it's a very clear—you have a clear public health need, and addressing that will answer the science questions that need to be answered that are fundamentally interesting science questions that we just have not answered yet and we need to.

Zierler:

Chicken and the egg question: With your affiliation with the Department of Physics and Astronomy which came about in 2014, I'm curious if you were doing things around that time that had more obvious physics and cosmology and astronomy applications and that led to your affiliation, or vice versa? Did you want to get more involved in those things, and that's why you hopped onto the department affiliation?

Wagner:

Yeah. That's a good question, David. So my postdocs were in physics, basically—

Zierler:

Yeah.

Wagner:

—and physical chemistry. And Delaware, when I came here, really didn't have a strong group in what you would call now soft matter physics.

Zierler:

Right, right.

Wagner:

There are other physics departments in the area that are quite good in that area, really excel, Penn being one, of course, nearby. And so I've always had a—and because of my physics affiliations through my postdoctoral work, I've always had a strong connection, especially in Europe, to physics departments. And so I have sabbaticaled with physics departments, and I have many collaborators because there aren't chemical engineers the way we think about them here. They are very often in physics departments there or physical chemistry departments. And so I felt, at Delaware, there was a need, if you will, to move collaboratively between chemical engineering and physics. And we had strong hard matter connections, hard condensed matter, electronic materials, magnetism, between material science engineering, chemical engineering, and physics, but we really didn't have much in the way of soft matter. And that's growing. We now have some faculty in physics who are really soft-matter-oriented physicists. But, for a long time, many people in physics, many physicists looked down on that field, high-energy physics, particle physics, that felt their questions were more fundamental in the reductionist view. I had—serendipity—when I was at Princeton as a graduate student, you could take any course you wanted at the university, and there was a course being offered by Phil Anderson, who just passed away this past spring.

Zierler:

Yeah.

Wagner:

Phil Anderson is famous, obviously, for his Nobel Prize, but he's the father, if you will, in condensed matter physics. And many people would view, rightfully so, that he really pioneered the idea of this concept of broken symmetry. And I took a course from him. I can't say I understood much. I can't say he took it seriously, because it was a first-year graduate stat mech course and it clearly wasn't what he wanted to be teaching. So the rest of the physics students really didn't show up for class anymore 'cause they realized they weren't learning what they needed to pass their qualifying exams.

Zierler:

Yeah.

Wagner:

But I and a few other students from other departments stuck it out and learned a lot. But, coming back to the physics, this idea that not everything in science is reductionist. So I kind of grew up in a science that said, if you get all the way down to quantum mechanics you could solve every problem.

Zierler:

[laugh]

Wagner:

The reductionist view. And Phil Anderson was very different. His view was things—emergent phenomena like superconductivity cannot be anticipated. Even if you have a theory of everything, you don't anticipate it. It arises, it's an emergent property that comes out of this idea, that he coined it or pioneered thinking in broken symmetry ideas. And I listened to that, and, of course, for his class, we didn't have a book on statistical mechanics, we read a collection of his papers. [laugh] And he made us buy a book of his papers and we read them for—you know, it was not exactly the best example of how to teach a first-year graduate course in a required topic.

Zierler:

[laugh] Right.

Wagner:

But it was fascinating for me, and I listened. I'm not sure I understood a lot, but I listened, and, again, smart guy and he's teaching me something. And so what I learned was that the beauty that you see in biology and in chemistry and in some areas of physics are emergent phenomena that you cannot reduce. You cannot just say, if I understood everything in quantum mechanics, I would have the answer to this. Life, things like that, consciousness, these are not properties that are easily thought about in a reductionist way. And Anderson was one of those people far ahead of his time saying, there are emergent phenomena that aren't trivially viewed in a reductionist way. And you're missing the beauty of nature and science by having this strict idea that everything has to be reduced back to particle physics or quantum mechanics or something. And so I listened to that and I thought I there was a lot to be said. So I think there is part of physics that really focuses on where these emergent phenomena come from in soft condensed matter, and how they arise. And maybe, as all physics looks for more universal ways in that arise, that it's not specific to this particular phenomenon, but that phenomenon is characteristic of many emergent phenomena. So we talk about, then, as chemical engineers making nanomaterials that are nanocomposites. Well, in the physics speak, we're saying we're breaking the symmetry using molecular theory to have emergent phenomena, which you didn't anticipate, which have useful properties, photonic, material properties, whatever, electrical superconductivity. These are things that aren't just—if you tell me I have this collection of atoms, I can't tell you if this property will occur. The property is a surprise.

Zierler:

Yeah.

Wagner:

A pleasant surprise. And then, why does that happen? It's not trivially reduced. So, coming back to my association of the physics, I always felt that that's sort of a way of thinking. And I, like many graduate students maybe working in theory and science, felt the same way in graduate school, where the power of quantum mechanics and the thinking behind it and the idea that we could reduce everything to the universal equation of everything, and that's still a great and worthy scientific pursuit, but we shouldn't forget that that will not teach us how life evolves and where consciousness comes from. And many of the beautiful properties of the world around us are emergent phenomena that are many-body collective things that aren't trivially reduced to these levels. And I'm still probably viewed—this field is viewed in some ways still as heresy, I think, by some purists, but I think honestly that, at least in terms of the rheology and soft matter and the areas that I work in, polymers and colloids, these are phenomena that aren't trivially thought about in a reductionist way. And there's beautiful emergent phenomena that come out of the collective nature of the behavior.

Zierler:

Just going through your career, I'm struck at all of the intellectual opportunities to pursue your research right in the Delaware campus. So the BIOMS program, the Biomechanics and Movements Science program, you joined this in 2015. How well developed was it before you started at that time?

Wagner:

Yeah. It's an interesting attempt, maybe one of the first on our campus, to really develop a graduate program that had no home.

Zierler:

Uh-huh.

Wagner:

That was really truly interdisciplinary. So we talk about collaborative programs, and I have joint appointments also now in biomedical engineering and that—but those are traditional ways of thinking, and the BIOMS program is attractive—although I must say I'm not as active in it as I was for a while when I had a student in the program, and I don't at the moment but would like to have more. But the idea was to really look across disciplines. And there is no home for this. There's no discipline of that. It's a program that really spans many different groups. You have mechanical engineers, you have kinesiology and physiologists, you have physical therapy people, you have chemical engineers, mechanical engineers, physics people. It's a broad range of people involved.

Again, the focus there—we were trying to develop, using the novel rheological response in these shear-thickening fluids, we were trying to develop devices that would enable people to recover better, rehabilitate, and also for people who have lost lower leg—transtibial prosthetics, the ankle, lower leg, foot—how do you replace the functionality there in a more biologically meaningful way? The typical carbon fiber composites or metal prosthetics don't have the right response. If you talk to someone who wears a prosthetic like that—I've talked to many people—they might have two or three different prosthetics, one for running, one for walking, one for this and that, because your biological systems adapt to what you're doing, running, walking, climbing steps. You have different muscle, ligaments, and they are nonlinear responses. But the materials aren't “smart” that we have. So we were developing highly-nonlinear, rheologically-interesting materials and then trying to use those.

And we still are working on that problem. There's some people working on this, and I just don't actively have a student on it myself, but there's a student who I coadvise in a group working on it. And the idea is to really see if we can harness these highly-interesting, nonlinear rheological behavior, which have some of this emergent phenomena that I talked about that you wouldn't anticipate. How can we use that to improve human health? In this case to provide people with a more realistic ability to recover their gait and their former activity with a single device that's passive, that doesn't have computers and batteries and motors and all that. It's just the materials behave more like the materials in your own body in terms of their highly-nonlinear response.

Zierler:

Now, of all of the research interests that we've been talking about, one that I think is a little difficult to place within your sort of intellectual constellation is manned space exploration. Where does this come in, where does your interest come, and what do you have to offer coming from your areas of expertise?

Wagner:

So, as I mentioned, in my formative years, I had the ability, on a little black and white television, to watch the moon landing.

Zierler:

Right.

Wagner:

And that leaves an impression on you.

Zierler:

Yeah.

Wagner:

And humanity is driven by exploration, and there is no more formidable place to explore—you could argue the depths of the ocean are interesting, too, and highly unexplored. So I grew up with Star Trek on television. You'd come home from school and watch Spock and Captain Kirk and all that. But the promise of that was a better world.

Zierler:

Mm-hmm.

Wagner:

I'll be honest with you, that television program was all about humanity joining together to explore the universe, and taking the ideas of humanity out to other cultures and places, but learning from those cultures and places in a peaceful way, mostly, although there were lots of battles, usual stuff. But the idea was that we weren't going to blow each other up with nuclear weapons. On earth we'd already done that. Now we were moved the next level where we were gonna—so I was always fascinated, but I also felt that NASA—it's noble mission of peaceful exploration of space and trying to push the boundaries of humanity. And then you've Carl Sagan talking about also the need to move off of planet earth ultimately and think about humanity spreading out in the galaxy. And so that's very inspirational, very lofty, but there's also benefits.

So I grew up with things like Tang and space blankets and computers coming, and you knew where it came from. You saw the Apollo program and you saw this stuff trickling down into your store, and technologies, calculators, stuff that came from the NASA science that was being done impacting your life as a kid growing up. So I always wanted to work with NASA. And by the time I got to the university, I was focused on my chemical engineering and that. There wasn't a strong connection to NASA, but in my own research at the University of Delaware, we're developing these protective materials for body armor and medical uses, then it was natural to think about when NASA was starting to talk about going to Mars. And I was convinced 20 years ago we'd already be on Mars. Now I understand, looking at the problem from an engineering perspective, how daunting that is, and how to live and work on Mars. And you watch a movie like The Martian, which has got some interesting things in it, and so we started working with NASA. And, luckily, Delaware is a space-grant university, so we come back to the University of Delaware, it's a land-grant university, it's a sea-grant university. I think it's the only one in the country that's all three. It's a space-grant university.

Zierler:

Mm-hmm.

Wagner:

So we have opportunities to work with NASA on our campus. Most of that's involved with satellites and exploration of space by remote methods. But, I said, look, I'm interested in manned space flight. I have a technology that protects policemen and soldiers. Why not astronauts? And NASA bit, and they got interested in it. And, to this day, we've now been working very heavily on components of the suit that will be used after the Artemis mission. So the initial Artemis landing suits will be more traditional materials that we have now, but we're working heavily with NASA on the prototypes for the next generation of suit, which will be the one we go to Mars with and continue our exploration of the moon with. More advanced materials that use the technology we developed here at the University of Delaware, and new things that we're developing now along those lines in composite materials for use in these extreme environments. So I've always been fascinated, and any chance I can get to work with NASA—it started this discussion early on, beforehand you had mentioned interviewing John Mather. And people at NASA—I've always had a very high regard for the science and the people at NASA, and the mission that they have. And to be part of that, I can be really proud. I'll also tell you that I have no shortage of students who would just jump at every opportunity to be involved in this.

Zierler:

Sure, sure.

Wagner:

I mean, this is still a draw for young, talented people to say, this matters, I want to be part of this.

Zierler:

Yeah.

Wagner:

And they see a future in working with NASA in that, and so I'm very proud to be part of those teams here at the university and at NASA, different sites around the country. We are all trying to really move humanity to other parts of the solar system.

Zierler:

Now, talking about your students, that's a good segue. We've been focused so heavily on your research we haven't really talked about your career as a teacher and as a mentor. So first, as a teacher, I'm curious, given all of your affiliations, given all of your research interests, at the end of the day, if you were only able to teach one course to undergraduates, what would that course be?

Wagner:

[laugh] Yeah. I fell in love with design, so it's a capstone class. And there's advantages to teaching very young students, freshman in that, and I enjoy that, sophomores. But there is something enamoring about design. And it goes back to a quote that my late colleague and coauthor of a textbook in the field of mass transfer, Fraser Russell, he would always quote Frank Lloyd Wright, and just to paraphrase, he said, "Analysis should become a frame of mind so that synthesis can become your frame of mind, which is design." So the architecture of Frank Lloyd Wright.

Zierler:

Oh, that's a very cool quote. I like that.

Wagner:

You analyze things and then you take that analysis and you design things. You're creative and do that. And, for me, that's a very satisfying course to teach because you've got people who are now accomplished, they've got three-and-a-half years, four years almost of education under their belt and they've got a lot of skills, and they really are chomping at the bit to design and create. And they've got great ideas. And you're part of a class—I'll teach 90 students and 30 different design teams doing product engineering and teaching them the methodology, the engineering way to think about it, and how to harness that creativity within an engineering framework to be successful. There's a little bit of business involved, and since I have a company that I spun out of the university and got interested in that, I think there's some value to having a rigorous way of thinking that some facets of business do bring to the engineering enterprise, economics, cost, but also focusing on the consumer. And so to see students—to teach them in a way where I'm learning as much from them often as they're learning from me at that level. So I enjoy teaching at all levels, graduate and undergraduate courses, but product engineering and design is a very rewarding course, very demanding but a very rewarding course to teach.

Zierler:

And, in terms of your career as a mentor to graduate students and postdocs, first, who have been some of your most significant graduate students and postdocs in terms of collaboration, in terms of where they've gone on, and also what is your overall style as a mentor for people at a more advanced stage in their student career? Do you tend to be sort of more hands on or hands off? Do you like to present specific research questions and watch them develop into dissertation topics? What is your style in that regard?

Wagner:

Yeah. So that's a great question, David. And we evolve with time and we hopefully get better at the job. Luckily for me, I had some absolutely remarkable students in my first group. And normally you have two new students when you're a new faculty member. I had four who were interested in working with me. And I went to the department chair at the time and he was very understanding and said OK. And it turns out, because we had more students than the projects, he was quite happy that I took three. And all three of them were absolutely superb, one of whom has stayed in academia and is quite successful on her own right, Lynn Walker, who's at Carnegie Mellon and is a quite famous rheologist—

Zierler:

Mm-hmm.

Wagner:

—and editor of Rheologica Acta now, and quite an accomplished academic in her own way with a long lineage of students of her own, et cetera. But I'm very proud of —all of those first three students, you know, you work most closely with.

Zierler:

Mm-hmm.

Wagner:

But they taught me a lot about how to do the job. [laugh] So I had, in that same class, the first class, I had a student by the name of John Bender [sp], and John had come from industry. He had worked in industry for a number of years at a very high level in air products. He had a family, and so he brought a certain level of discipline to the research group that someone coming out of industry with a family would necessarily—a seriousness about doing the work and really anchoring ideas and thinking carefully before you jump. And John taught me a lot, and that's how I got interested in the shear-thickening fluids, because he saw things in the lab, and we talked about it and went forward. And another student, Sanjeev Rastogi, who is where I started working very heavily with DuPont and with his project, and it was computational and generated a lot of good collaborations with DuPont that then flourished into larger programs. So all three of them were extremely valuable to me in different aspects of my career later on. I learned a lot from the three. I've had 50 students, another 20 postdocs, and many, many undergraduates work in my lab. So we'd spend hours just going through the names and what they accomplished. And I collaborate with many of them, just like my own advisor 25 years later.

Zierler:

Yeah.

Wagner:

I have published papers with some of my very earliest students. Twenty years later they come back to sabbatical, students in Europe, for example, who came back and did a sabbatical with me and published paper together after 20 years. It's very rewarding to see that kind of work. But I think every person is different, and if you're willing to learn from your students as much as they're learning from you, that's a good way to operate, because these are smart people who have good ideas. One thing, though, that I will say that I think one of the key roles of a mentor is, people come to science, like I did, too, from a textbook kind of learning background where there's always an answer.

Zierler:

Uh-huh, right.

Wagner:

You can always go find the answer. There's a question, there's an answer, right? That's what textbooks are like. And research is different. You want to pose a question for which there is no answer. That makes it a valuable research. And that's a learning process that I began to appreciate has to be cultivated in young students as they start out, because they come to the problem with the idea that the answer is already there, they just have to find it. It exists, it's already been done, it's in the library. I've had this discussion with students. I was, like, if you find the answer in the library we failed, because why are we working on it? We already know the answer. Let's go ask another question.

Zierler:

Yep.

Wagner:

And so the whole idea of doing a literature search of the library is to make sure that someone hasn't already answered, as much as anything else. And that's a mentality—so I'll have really excellent students who, early in their career, let's say they go to the lab, we talk about an idea, we have a hypothesis, we set up some experiments, we go do them. And they'll disappear for a while. I like to meet often with my students. They'll disappear for a while and then they'll come back sheepishly and say, "OK. We have to have a meeting." I said, "Yes. I'm very happy. I've been waiting. So show me what you got." And they're, like, "Well, I did it three times, and each time it comes out not the way we thought." And I'll lean back and think about it and start to smile. And they're, like, totally upset. They're thinking, oh, my God, he's going to fire me or something. He thinks I'm incompetent. And then I'm, like, "That's really interesting."

Zierler:

Yeah.

Wagner:

And then they get really upset, because that's not the reaction they expected. They expected that they failed to get the right answer, the answer we thought we would get. And my comment to them was that science proceeds by exactly that, by that we see something that doesn't make sense to us. Because, if all we're doing is answering the question for which we could've guessed the answer, then we're not really pushing the boundaries of science. We already knew the answer.

Zierler:

Sure.

Wagner:

And we just confirmed we were right. What's the fun in that? Science is all about finding out you were wrong, your intuition and your thinking was wrong, and that there's really something much more interesting to work on that needs more effort and thought. And for a graduate student who's just starting out who comes from a typical undergraduate background of everything's a textbook problem that has an answer, this is a horrifying moment.

Zierler:

[laugh]

Wagner:

And part of your job as your PhD advisor is to help guide them through that valley, if you will, of doubts and despair and say, no, you actually have discovered now what will be probably the question that will now occupy you for the rest of your PhD.

Zierler:

Right.

Wagner:

Because it's worthy of answering because we didn't know the answer and it's unexpected.

Zierler:

Yeah.

Wagner:

And that, to me, is the joy in research is finding out you were wrong. But for students, the advisor is always right, so if the advisor has a hypothesis and talks about it with you, then, of course, you've got to get the advisor's answer, right? And if you don't get that it's a tragedy. And that's the exact opposite from me. I'm, like, oh, you didn't get the answer I thought? Well, then, I was wrong and that's great, because that means we don't understand something here and let's take a look at it. Now you have my attention.

Zierler:

And this is probably—this gets right back to that initial interaction with Bill Russel, right?

Wagner:

Absolutely, yep.

Zierler:

That's really the way that these collaborations are successful.

Wagner:

Yeah. And he was quite interested in me because, at that point, we really focused on that question, that theory, and thought about it. What opportunities came out of that. I mean, that was eye opening to me, too. I didn't know what to expect, saying, gee, I don't think this is right. I think there's something more here. And his reaction was very much, after carefully looking at what I gave him, the papers and the derivations and showed him, he thought about it for a while and he came back and said, "Yeah. Let's work on this." He was disappointed, of course, that he hadn't seen it himself, as any scientist would be, you know, you overlook something. It's not a critical flaw or anything. It's just, like, oh, there was an opportunity there and now that we see it let's spend some time on it. And that maybe was a good—just like Ed Ko not berating me for taking apart his equipment on the bench, but being patient, trusting that I would work on it a little bit and put it back together and do what I said I would do. That kind of faith in the student is important, because as a student you feel very uncertain of yourself. You're doing things you're not used to doing and you're in uncharted territory and you're very vulnerable because you certainly want to succeed as a student. And you have to learn to fail. You have to learn to make mistakes. You have to learn to be wrong and then recognize that and move forward. And those are things that we all have trouble with, even in our own lives. But students, in doing a research, have to get used to the fact that there isn't always an obvious answer, and if there is, you probably shouldn't be working on that because it's not a worthy question for research.

Zierler:

Yeah. So the next thing I want to talk about is rheology. There's so much to discuss with rheology.

Wagner:

Yes.

Zierler:

So the first thing, just an observation and we'll go from there, on the basis of us coming together is, of course, SOR is one of the major member societies and one of the most important member societies of AIP. And, in my interaction generally with SOR, it's remarkable how tight knit the community of rheologists is generally.

Wagner:

Yeah.

Zierler:

And a theme of our discussion so far—it's obvious that, in terms of your research interests and your expertise, you are pretty hard to pigeonhole. And so I wonder if rheology serves as a sort of catchall in terms of, if you had to define yourself as a something, and I didn't give you so much space to fill in the blank—

Wagner:

Yeah.

Zierler:

—is rheology or being a rheologist, would that be the closest to sort of catch-all of the things that you've been involved in over the years?

Wagner:

It's certainly a core feature of it. I would say I came—I wouldn't have said as a graduate student that I was really a rheologist. That sort of came a little later in my career that I developed the consciousness that I would be a rheologist.

Zierler:

Yeah.

Wagner:

But rheology is an interesting way of thinking about problems and solving problems. And in my own interaction coming back to the society, it's evolved a lot over the time I've been involved. But one of the fascinating things—remember in the beginning I was mentioning the beauty of this discipline of colloid and interface science was that you go back to the giants of the field like Einstein and others, Nobel Prize winners like De Gennes in polymers, and you have people who are applying very high levels of mathematics, statistical physics, solving interesting problems at molecular levels and mesoscale levels, and asking big questions about emerging things, and that's rheology. That is rheology.

Zierler:

Yeah.

Wagner:

We're doing that. We're measuring that. We're living that dream, if you will, in many ways. I think, coming into the field of rheology, it does catch a broad range of different things. It could even be broader, I would argue. But I would argue that one of the things that got me excited about it was, of course, my former colleague and mentor, Art Metzner at Delaware, who was one of the—he wasn't one of the founding fathers, but he knew the founding fathers. He would show me pictures every now and then of some of the great people who were defining the field that he had met and interacted with. And he, like me, had come to rheology from catalysis. He actually started at Delaware doing catalysis and then he switched. But he knew all the early people in the field. And his very sharp intellect—and he was editor of the journal, so he actually knew the literature. Before there was a World Wide Web, an internet, you had Art Metzner and you could ask Art Metzner, "Art, did someone work on liquid crystal polymers?" And he'd cite chapter and verse and whose papers to go read. And he'd know exactly what year they were published, who published them, and practically all the details. He was our web of science for rheology living, breathing, long before there was the internet with this information on it. And so I saw the giants of the field through his eyes, and pictures and stories he would tell, and the papers that I would read. And that was very inspirational.

So that community was really an international global community of people very early on with common questions that were foundational, fundamental questions about science that they were trying to sort out in relationship to this field. And they were way ahead of their time in many ways asking deep questions that are now in physics departments and places in soft condensed matter very prominent. But it was a small group, and they were unified by this concept, and they coined the word "rheology" and went forward. So they created a discipline that suited their intellect, if you will. And it was fascinating to me, and so then I fell in love with the math and the physics and the applications that it could be applied to. And then you suddenly realize that like-minded people are gravitating to this field. And it's ecumenical. As far as I know, we've never turned anyone away. The other day, at the last meeting, I met a vulcanist, someone who measures rheology of magma in volcanoes.

Zierler:

[laugh]

Wagner:

Insane! Not just in the lab but they go into field work—

Zierler:

To volcanos?

Wagner:

—in rheology with the rheometers that are—so just crazy stuff like that. And you're thinking, wow, that's cool! And so it's a field that doesn’t seem to have a boundary where—there's no fence around it that says you can't be a rheologist.

Zierler:

So that gets me to my question. It begs the question: Why is there not a department of rheology? Is it because it's just too—

Wagner:

It's just—yeah.

Zierler:

—poorly defined?

Wagner:

I think it's because it's so ecumenical and so broadly—you could be working on metals, you could be working on granular flows, like the planetary something, you could have an atomic viewpoint, you could have a thermodynamics viewpoint, theory, experiment, simulation. And rheology creeps into all problems.

Zierler:

Yeah.

Wagner:

At some point, you make it flow, you squeeze the toothpaste, whatever, you mix it. Rheology ends up somewhere in the problem, whether it's the most important component or not, it's still an essential component of solving many, many real-world problems. You process everything, food, polymers, high technology, computer chips, you name it. There's rheological questions along the way that have to be solved for those technologies to work, and they have deeper scientific underpinnings to them. And rheology sometimes is the end goal. We want a certain rheological behavior because that's what we sell the material for. So the long and short of it is rheology finds itself everywhere. It's kind of one of those things where every company needs at least one rheologist. They might not need more than one, but they need one good one, and some have more. But often they need one. They'll often say, hey, we need a rheologist. We don't have one. We need to hire somebody 'cause we need someone who understands this, and how structure properties and flow and processing are all connected. So the field is broad and, in many ways, like I said, I don't think anyone's ever been turned away from rheology by being told, your problem isn't rheology.

Zierler:

Yeah.

Wagner:

If you think it's rheology, it probably is and you're welcome. [laugh]

Zierler:

Right. So, Norm, just to bring the narrative up to present day—

Wagner:

Sure.

Zierler:

—and getting back to this idea of focusing on whatever is front of your nose, so what is in front of your nose these days? What are you working on?

Wagner:

Yeah. So we're excited to do a couple of things. So from a framework standpoint, I like the French term that's used for this, it's "structuration," which we don't quite use in English, but I think you understand it. And we're looking at 4D. So the 20th Century was very much structure-property relationships of materials and emergent properties from that. But time plays an important role, and Art Metzner knew this. On the front of our building is engraved some hieroglyphs, one of them is a dimensionless group called the Deborah number, which is the time of the process and the time of the material, the relationship between these timescales. I mean, this is engraved in stone, if you will, on the front of our building. And so I would argue this century what we're thinking about more in the beginning of the 21st Century is much more four-dimensional things.

Time is another part of the problem that's coupled to the other three dimensions of structure. And so we look at 4D structuration. And so a material has to behave a certain way at a certain time with a certain structure. And that is very essential in the materials processing industry and many consumer products. Something that's a gel in your hand, like a shampoo, has to flow when you squeeze it out of the bottle, et cetera. And so the structure is different at different times during this process, and that's important to understand. And so you need tools of scientific discovery, so I've been working a lot on, like I said, developing new neutron scattering tools that are time resolved and structure resolved. So we're doing a lot in that front. How do we study these materials, not just the three-dimensional structure at the nanoscale, but also how that evolves with time, and how the structure-time property, and how do properties emerge—different properties emerging at different times when you want them to, hopefully, or maybe creatively. So that's a broad concept, but, here again, I'm talking decades of work, not years. And then, applying that.

So some of the problems we're working on are—we're motivated, we have been working for many years on biopharmaceuticals, stability and delivery. Rheology is very important. If you want to inject something through a syringe you cannot have too high of a viscosity, but you need to have a high protein concentration, the therapeutic has to be at a high enough concentration in the syringe that you make one injection. So you see people getting cancer therapy in the hospital with an IV bag and a slow drip and a very dilute—and it takes half a day and a lot of money, and it's very painful for everybody, when some of the drugs now can be injected. You can just do it at home. You can take your cancer therapy at home, much more comfortable and much safer, much less expensive, much more accessible. But that's a rheology problem. It's simply a rheology problem. Stability and colloid science, but it's a rheology problem. And so we work on these problems, but, again, from a molecular viewpoint. So you could ask yourself, how do I change the primary sequence of this protein to have the right rheological properties in this concentrated solution? That's an emergent property of a collective of these molecules in the folded state, et cetera, et cetera.

So, without getting into too much detail, that's one example, where this all comes together to make a product that helps cure people and may someday be relevant for the coronavirus if we have a vaccine. We may end up with this problem of dealing with the rheological properties so we can inject it, et cetera, stability. We work on NASA. We're very interested in astronaut protection. How do we push the boundaries? I'll tell you right now, one of the great challenges is, on the moon, the resources we need are in the shadows. In the shadows it's 40 degrees Kelvin. There are very few materials that you can take into a 40-degree Kelvin environment for any length of time and have them function properly. So that's a new challenge. We're just starting to think about that. In terms of the space suits and the soft goods, the soft parts and the hard parts of the space suit that we've been engineering to have super-high performance. Astronauts who live and work on the planet of Mars or on the moon have to be able to wear a suit for eight hours to walk around, do things. It can't be the Apollo suits that weight 300 pounds or are designed for zero gravity for only a few hours of use on the moon and then we're out. So these are material challenges, but then they raise some interesting science questions. What do the materials do at these low temperatures? What is the physics of that? We have other problems where we're trying to do a little more theory.

So I have always been interested in nonequilibrium thermodynamics, and this comes back to the giants of the field of rheology. One of the great questions of the 20th Century which wasn't resolved was, what are the rules when you move away from equilibrium? Gibbs, Boltzmann gave us the framework for equilibrium thermodynamics. We teach this stuff. We use it every day. We solve real world problems and science problems all the time using it. But, as soon as you push a material out of equilibrium strongly, such as processing a polymer, the rules aren't there. The standard equilibrium thermodynamics is insufficient to describe this, and we know that. We've known that for more than 100 years, and we still don't have a framework, I would argue, that is on the same footing as Gibbs and Boltzmann did from a classical and a molecular viewpoint, but we have ways of addressing the problem. I'm very blessed at Delaware by having a senior colleague, Antony Beris, who's one of the world's experts in this field. I spent a sabbatical with Hans Christian Öttinger at the ETH Zurich, another giant in the field, learning and trying to develop this idea.

But this framework, this nonequilibrium thermodynamics framework, is the answer to our field. When we understand that framework then we have the rules, just like classical thermodynamics—equilibrium thermodynamics, sorry, they give us the rules to how to connect everything. You know, conservation of energy, first, second, and third law, entropy production, things like that. That we know and we use that heavily as scientists to solve our problems. We don't have those rules, and that's what rheology ultimately is, is asking that question, but for nonequilibrium, we process things, we shear them, we take them out of equilibrium. How do they behave? Yes, that's the question. From a theory standpoint, we don't have the framework that tells us how things should fit together. And we struggle with that as a discipline, and it's a very rich intellectual area to work in that the giants had worked on 100 years ago, and we're still struggling with to this day. I find that fascinating.

So that's another area under my nose where we're really trying to build those rules. We're trying to understand and then test them, test the ideas. So a lot of the work that we do in the measurement science ultimately is testing materials far from equilibrium, and asking how do they behave and what new phenomena occur or don't occur and why, and can this predicted or not? And the Journal of Rheology is just full of all sorts of theories and experiments and people stewing back and forth shear banding and highly-nonlinear behavior that's unanticipated, where does it come from, why does it occur, can we describe it mathematically or not? And that's really a question of nonequilibrium thermodynamics. So I have a lot of respect for the people working in that field. I have learned from them. I collaborate with them. Like I said, I have colleagues and friends who I've done sabbaticals with and published with and try to understand. And I think that's an area that we can hopefully contribute to. But it's gonna be maybe 100 years from now to understand this problem.

Zierler:

Yeah. [laugh] Well, Norm, now that we've brought it up to the present in terms of your research, for the last portion of our talk, I want to ask you a few broadly retrospective questions about your career. And the first one is, I'd like for you to talk a little bit about feedback mechanisms for knowing when a particular research endeavor is working and when it's not. And I'm specifically curious about—many scientists can spend their entire career in a relatively narrow field of study. And let's be honest, you're all over the place, and you have been all over the place, and I wonder if one of those challenges has been sort of not just taking on all of these different research endeavors, but also learning the rules of a given project and knowing—how do I know that this is working? How do I know when I've hit a wall? How do I know when to sort of give up and work on something else? And how do I know when it's worth my time to sort of hit that wall again and again until I break through? That's a difficult question to answer if you've only worked in one area of science your entire career, and so I wonder how you deal with that given the fact that you've been in dozens of research endeavors over the course of your career?

Wagner:

Yeah. That's a great question, David. I think part of my training, like I said, in Germany and then also at the national labs, Los Alamos and NIST in particular, taught me that good questions are difficult ones. The answers aren't going to come easy, may or may not reach them, but maybe we could contribute. Maybe we can make a contribution, make a step towards finding the answer. And sometimes we're wrong. Sometimes we try something and it doesn't work. But I think that questions—although maybe you say, well, I've worked on many, many different things. Some of the underlying themes of this nonequilibrium thermodynamics and the ability to connect molecular structure to atomistic to mesoscale to emergent properties, you're just seeing different manifestations of that, whether it's a liquid crystal polymer, a monoclonal antibody, or a colloidal suspension or whatever. We're actually using the same tools, thinking, and techniques, we're just applying them to different technologies or different materials, but it's the same theme. So, in some ways, I think that questions are good questions and they will persist beyond my academic career, I'm sure. Hopefully, we can make some serious inroads, and in some cases, we can solve problems with particular materials or technologies that are of technological use, as we talked about. In other cases, we just publish interesting science papers, then 20 years later someone picks up and does something with them.

Zierler:

Yeah.

Wagner:

I've seen that happen. Can't anticipate. So part of it is, you say, well, you do good science. The science is a method, science is not an answer, science is a way to get an answer. It's a technique, a methodology of thinking. And if you do science, you may fail, but failure in science often means you've actually learned something important, usually. I mean, if you just give up, you fail and don't learn anything, but if you try to understand why you failed, then you probably actually succeed somewhere. You've actually learned something. And you may say, OK, well, I'm not going to pursue that, but you publish it. And then, 10 years later, somebody's working on a seemingly unrelated problem looking for this. And the beauty of the scientific literature and the scientific method is, we all contribute something. We don't necessarily know who's going to use it or why, and it may be a while. But then someone picks it up and uses it. And when you have a longer career, OK, 30 years, some of my colleagues 50 years, you see that time and time again, where you did something and you thought, well, OK, this is done. I'm gonna move on. I don't see myself working on this anymore. There's other questions I want to spend—there's a limited number of hours in the day, there are other questions I'd like to work on. But you publish it, and then somewhere along the line someone picks it up 10 years later and says, hmm, this is what I needed. I needed this information to solve my problem. Then you read about it, see a citation, and you're, like, oh, what did—so don't underestimate the fact that the philosophy of science and the methodology of science is really, from a human endeavor standpoint, solves problems. And even though you fail, you don't give up. You fail, you learn from that failure. You probably actually discovered something interesting and useful, even if it's just the question. And it will come back to be valuable for somebody else, maybe not you, maybe somebody else or yourself 10 years later might revisit it. And I've done that, too, where I've revisited a problem with fresh eyes and fresh technology or fresh thinking 10 years later, and suddenly it becomes clear what the answer is. But you had to have that failure 10 years before, otherwise you wouldn't think about it later. So I'm much more optimistic that there really isn't—giving up is failure, maybe.

Zierler:

Yeah.

Wagner:

But failure in science is part of the job. You should fail, like I said. The interesting questions—

Zierler:

Right.

Wagner:

I mean, it's not obvious. And then you publish and then you see what happens. And sometimes nothing, and other times 10 years or 5 years or sometimes even less someone picks it up and runs with it. And you're, like, wow, that's great. I did something and someone cares about it, and they used it to solve their problem. Or you might even become part of that solution yourself.

Zierler:

So staying on that topic of success in the broader way and the more inclusive way that you're defining it, I wonder if you can talk a little bit about success and the personal satisfaction you derive from it with regard to the way that your research might really answer an academic question, whether it might help to resolve or improve a societal problem, or whether something that you came up with has real commercial viability, not from the profit margin, but for the idea that this is something that can get out to market and really improve things. So, in terms of the personal satisfaction that you derive from your research in looking at the places that it ends up, do you tend to divide those things into those rough categories, or do you sort of take a holistic view of your overall contributions, wherever they may land?

Wagner:

Yeah. I don't know. We're all human. We all like recognition. We all like to see what we do be meaningful. I would say that an academic career has different pathways for gaining that personal satisfaction. Teaching, at first, I was not really understanding, but my wife is a high school teacher, so I learned more from her, perhaps, about teaching than anybody else. And I've learned to love teaching because I saw how much she loved it. And I realized that this could really be rewarding, and it is a very rewarding career in and of itself. But as I've sometimes had arguments in our faculty senate in talking about new ideas and new courses, you could ask the question, how does knowledge become taught in the university? Well, that's research. So doing research and then having that knowledge end up in a textbook that you write, and then being taught in a classroom is very rewarding because you realize that the human endeavor is moving forward, and you're part of that.

So all the things you mentioned are parts of that, and we all are human and we all like recognition. We all like to get awards. We all like to have people tell us we're doing a good job, and that's important in life. But there's something also just rewarding about knowing you're part of this very—what can be a very positive way of thinking about the world and society and making the world a better place in your own way. Not everybody solves climate change as their signature thing in their life, but there is a lot of little things you can do that matter and make people's lives better. And sometimes it's just teaching people, and they go off and do interesting things and use that knowledge. So there's a lot of personal satisfaction and rewards just by doing the job of an academic researcher, teacher, scholar. I think if you take that job seriously and try to do your best at it, you'll be tremendously rewarded because you can feel like—you get a sense that people are learning and they're going off and doing good things, and you're maybe generating ideas which then people can learn and go use. And that cycle can be a positive cycle, can be a virtuous circle kind of idea, and can be a good thing. So I think in that way it's holistic, and I'm very glad, in the end, that I ended up a university because, although I was a horrible teacher at the beginning, I would argue, I was willing to learn. And, like I said, I learned a lot from my wife who is a high school teacher and loves teaching. And when you see that, when you're around someone who's really very good at the job and very passionate about it, it rubs off on you, luckily.

Zierler:

Sure.

Wagner:

And then you realize that there's a lot to be gained. I mean, you teach people something and they teach people something, and all of the sudden lots of people learn something. So there's a lot to be said for teaching as a career, and then also teaching where you're bringing new ideas and that maybe some of them are your own, that you've done in your own research that becomes the textbooks that the students are using. And I think that's very powerful.

Zierler:

So, as a matter of tracing your intellectual history and maybe using that phenomenal story about in Ed Ko's lab where you took apart the instrumentation—

Wagner:

Yeah.

Zierler:

—as a moment of well-meaning naivety or immaturity or whatever you want to call it, fast forward to the present and all of the knowledge you've gained, the wisdom, the perspective, the experience overall. I wonder if you can comment, sort of using that moment to today as sort of narrative endpoints, what are things in science that you feel are no longer mysterious to you personally? Things that, over the course of your career, you really didn't understand, and not just because you didn't read that chapter in the textbook, but because it's like, I just don't get this; this is beyond me. What are some things that stick out that used to be really mysterious to you that were beyond you that you feel like, at this point in your career, you really have a solid handle on?

Wagner:

Hmm. That's a good question. Maybe I'll answer it in a way that might not be the obvious way to answer the question. It's not a specific knowledge. I think we all go through this period early in graduate career, as I said, where you kind of have to reset your mind where it's no longer, the answer is there, I just have to go find it. I need to figure out what the right question is to ask that's worthy of my time and effort, and is sufficiently difficult that I can actually make a contribution by working on this problem as an academic researcher. Not everybody has to be an academic researcher, don't get me wrong. There's a lot of room for people who do their job and do development work and production work, and we need that as a society. But those of us who are lucky enough maybe to have that opportunity have to be willing to cast aside the doubt of, well, I need to be safe and secure and get an answer to the boss. You have to be willing to ask questions which maybe are rubbing the wrong way, maybe are controversial. You have to be willing to have people tell you you're wrong, maybe in not so polite ways and argue with you and say, no, I'm right and you've got the wrong idea. You have to be willing to engage in that.

And that's difficult when you're a student and first starting out. So as time has come—you get reviews back on a paper and some of them are damning. You have to be willing to look at them both from a rational viewpoint and say, is there something here? Did I make a mistake, or did I not write a good paper draft? Should I rewrite my manuscript, should I withdraw it, whatever? But also, maybe they're wrong and, OK, so they raise good questions and I need to answer them. And they're scientists and I need to give them the evidence so that the reviewer will change their mind and say, no, you are right after all. And that takes a certain level of gumption and belief in yourself, but also willingness to throw yourself out there and to be wrong occasionally. I mean, sometimes you have to admit, hey, I got it wrong; let me go fix it and not just give up. So I think part of it is just this life lesson of the methodology of science and what it's all about, and how our role isn’t just to get the right answer all the time. Sometimes our role is to ask the question. We may not answer that question, someone else may answer it, but it was a worthy question. There are a lot of questions you can ask. Not all of them are worth your time to work on. And understanding which questions are really the important questions and the answers to which will actually make an important contribution, those, I think, are things that come with experience more so. I mean, you might get lucky at an early age, but often it's listening to other people and getting some experience, and communication.

And, during this pandemic time, it's really a tragedy because we're not able to meet in scientific meetings, and people underestimate how important that is to have those conversations with other people. Sometimes informal, not just in the lecture room giving a presentation, but just in the hallway or wherever, or in the department, in the lunchroom and all of that. All of these things really matter in science because this communication of ideas and sharing—and if you're open to that and you're willing to listen and learn. And, as I said, early in my career I was very happy sometimes to go to my friends and colleagues and say, that's a really good question. Do you mind if I work on that for a while 'cause it sounds interesting to me? With your permission, I'd like to play with it. And most people—I virtually had no one say no. Everyone's, oh, yeah. That's great, you're interested in what I'm interested in, let's work together sometimes. So I think—I'm not answering your question like, did I read something in a book and that—I would argue this field of nonequilibrium thermodynamics just becomes more difficult and more complicated the more I learn about it, and it's very deep from a philosophy of science standpoint, too. And I think, as a young intellectual, I had trouble with that. I had trouble with these ideas of, what is knowledge and what's our role as scientists with that? And I would say now I'm much more comfortable understanding that, and hopefully I'm able to mentor my own students through that phase in their life where they might be doubting what they're doing and why, and what the enterprise of science is all about, and how to use that as an engineer. That's another question, too. How do you balance the basic science and the engineering application?

Zierler:

Yeah.

Wagner:

And as chemical engineers, that's what we do.

Zierler:

Well, Norm, I think, for my last question, it's a forward-looking question. I think one of the real stand-out themes of our talk is your approach being both open-minded and flexible, both to the kinds of research projects that you choose and the way you go about tackling them. And so I wonder, looking ahead in your own career, what are the areas of inquiry that are most compelling to you personally, things that you may not have worked on in the past, but because you've demonstrated such flexibility and open-mindedness to thinking about new problems and taking them own in novel ways, what are some of the issues both of academic value, commercial value, societal value that you want to take on in the future and why?

Wagner:

Hmm. Well, let me give that some thought, David, for a second.

Zierler:

Sure.

Wagner:

I sort of answered part of your question with this idea that there's this over-arching need to understand the framework of nonequilibrium thermodynamics, what happens to the world as we move forward? Where does these emergent phenomena come from that we talk about, and how do we engineer them, how do we design them?

Zierler:

Mm-hmm.

Wagner:

Like I said, too, the idea that time plays an important role in the timescales, people have known that for a long time, but it's becoming more and more apparent that we need the tools of scientific discovery to be able to make these measurements in both space and time in a way that resolves issues and can give us answers, give us clues to how the world works. I still think the promise of nanotechnology hasn't been fully realized. And I was part of the early—around the year 2000 there was a lot of road mapping being done about how we're going to get to the promise of nanotechnology. I think we have only scratched the surface of what's possible there. We've made significant advances, but we're not at the point where we can really maybe harness all the knowledge. There's just a vast diversity of discovery and new materials and new phenomena, but it's not been understood in a more systematic way that we can harness that in a design-based way and say, well, we can really just go solve a lot of problems. There's a lot of still hard elbow grease and discovery that goes into solving nanotechnology or discovering new nanotechnology phenomena, so I think there's still a lot to be done there where we would understand the rules better. But that also comes back to the nonequilibrium thermodynamics, at some level that's involved, and then the connection down to the atomistic level. So we're still exploring the world in the sense that there's a lot of good questions out there. And then there's this whole field of biology. And, in many ways, I was very interested, as an undergraduate in—I minored in philosophy but not classical philosophy, philosophy applied to linguistics, because I was also interested in computer languages. And that's one way to think about it, is to view it from a study of logic, philosophical logic, and then applying that. And that's how computer science really has made huge advances. And so, being at Carnegie Mellon, that was something easy to grab ahold of.

Zierler:

Mm-hmm.

Wagner:

There was a lot of that going on with people trying to build the best chess game and doing that. But I think there's a lot there, too, in terms of consciousness. The information side of biology that we only are beginning to harness, the power of that. I mean, biology is a lot of information science being applied to generate things like life. And, somehow, all these pieces do fit together, but they're not there yet. You see different groups working on different parts, and maybe one of the holy grails for human discovery is consciousness. How did we become self-aware and conscious? That's clearly an emergent phenomenon of a very high complexity that we really have no idea where this comes from. And so I think that's a very lofty goal, and I'm not working on that. It's way beyond my capabilities. But I think about it. I think about—that's an example of an emergent phenomena that you'd love to be able to answer the question, where does this come from? But there are many other things along that we could do maybe that are interesting. And I think the biological world—I grew up with a very primitive biology education before molecular biology was really commonly taught in high school and college at a level that it is now, so I've kind of retread and learned about it through my collaborations, but I'm very much interested in what we could do there, too. You can imagine—and DuPont is a good example of this, where they were, for a long time, engineering new polymers from using biological roots to producing materials that we couldn't do synthetically. So you can do things—I'm a chemical and biomolecular engineer and in that department, and whether I'm transforming matter by chemistry or transforming matter by biology, we don't make that distinction so much anymore in our discipline. We do both.

Zierler:

Mm-hmm.

Wagner:

And so I think there are tremendous untapped opportunities in the harnessing information and biology that can then design and create materials with interesting properties that we only now are beginning to tap into. You hear a lot of work, bio-renewable, bio-compostable, bio-based systems, but we're still very primitive, I would argue, in our ability to control and harness that. I mean, ultimately people are talking about artificial life and things like that. But just the ability to really transform materials into what we want as chemical engineers using biological roots. I'm fascinated by my colleagues who do this for a living, and I'm happy to collaborate with some of them. So those are areas I think are interesting and they all have common themes of new and emergent complexity and nonequilibrium phenomena that are inherent in those topics that we just don't really have good engineering or even science and engineering tools to handle.

Zierler:

Well, Norm, it's been absolutely terrific talking with you, remarkably immersive and engaging in all of your answers, and there's as much information that you've shared as research areas that you've been involved with, so I really want to thank you for your time.

Wagner:

Oh, thank you, David. It's a pleasure to talk with you about these things. And your questioning was very insightful. It forced me think on the fly sometimes about such things.

Zierler:

[laugh]

Wagner:

But that's what—as academicians, we're supposed to be challenged, right?

Zierler:

That's it.

Wagner:

So I appreciate the challenging questions today.

Zierler:

Excellent, excellent.