A gift of knowing without seeing


Photo: Megan Wolff/Iowa State Daily

John Clem, distinguished professor emeritus of physics and astronomy and senior scientist emeritus at the U.S. Department of Energy Ames Laboratory, is reknowned around the world for his work on superconductivity.

Elizabeth Polsdofer

Most people struggle with physics. It is full of differential equations, laws, Greek letters and words like “electromagnetic” and “inertia.” 

Even with extensive tutoring and hours hitting the stacks, many people will never “get” physics or become physicists even as they watch its fundamental laws like gravity, conservation of momentum and simple harmonic motion each day.

Perhaps that is what makes John Clem, distinguished professor emeritus of physics and astronomy and senior scientist emeritus at the U.S. Department of Energy Ames Laboratory, so special. 

Not only does Clem “get” physics and its many hidden, intricate laws, but he has the rare gift of knowing without seeing. 

Clem is a world-renowned condensed matter physicist who specializes in superconductivity theory.

“John is probably one of four or five people in the world who does this kind of work, which is electromagnetic structures in superconductors, and John is always right,” said Doug Finnemore, distinguished professor emeritus of physics and astronomy. “I have never seen him make a mistake. Now I’m sure he has made a mistake but it’s rare.” 

A brief history of superconductivity

Superconductors are conductors — usually metals or ceramics — that can conduct electricity with zero resistance at cool temperatures. 

Since their discovery nearly a decade ago, superconductors have been the superstars of the condensed matter physics world.

“What really got me involved in research in superconductivity — I guess it was during my second year — I was taking quantum mechanics from Bob Schrieffer. He’s the ‘S’ of the ‘BCS Theory of Bardeen, Cooper and Schrieffer’ and … I was number one in his quantum mechanics class,” Clem said. “He said he was impressed with my work, and he said, ‘Would you like to do some calculations with me and do some work with me?’ I said, ‘Well, that sounds great,’ except I had a teaching assistantship at the time and I couldn’t get out of it.”

The Bardeen, Cooper and Schrieffer Theory, also known as BCS theory, is the fundamental theory of superconductivity. 

BCS theory is the first theory to examine what happens to superconductors at the atomic level.

Inside a theorist’s mind

“I’m a theorist; I’ve never done any experiments in superconductivity, but I’ve always enjoyed stopping by a laboratory and seeing how things were going,” Clem said. “Sometimes I even had the opportunity to turn a dial or something like that to see what happens. … I remember a very pleasant experience when I was collaborating with a fellow physicist at Argonne National Laboratory, and he and his co-workers went off to lunch one day, and he let me sit in his lab and play around with the apparatus. I didn’t break it, and it was okay. I got to turn up the current, then turn down the current, turn up the magnetic field; it was a lot of fun.”

Finnemore, who works with experimental condensed matter, recalls when Clem asked advice on how to patent an invention Clem had theorized under the guise of wanting to collaborate on an experiment.

“I said, ‘Do you have a data book?’” Finnemore asked Clem.

“Data book? I’ve never had a data book,” Clem told him. Finnemore said Clem showed up in office again the next day with all the data Clem needed for the patent.

“It was in the afternoon John showed up at my office. I don’t know how much he had, maybe 50 pages, in this data book for his invention and he patented it and the patent went through: ‘BOOM,’” Finnemore said. “Didn’t need an experimental verification; it worked, didn’t need anything. Took us about three years to actually build one, and it worked.”

“My work tends to believe in the applied side because I’ve always been interested in applications of superconductivity,” Clem said. “I would like to have the feeling that what I do has some, if not immediate, eventual application in superconductivity. … There are some theorists who like the idea of just the mathematical world, just the theoretical world and just working in that world without any thought of an actual experimental applications or experimental manifestations. I’m not that sort, but I respect those people. That just never interested me.”

World-class editor

“For my point of view, one of the big things he did was when high temperature superconductivity broke, about 1987, there was just a flurry of activity. Everybody jumped on it, and there was maybe 30 to 50 publications per week, and John would read the preprints that were sent here, and he would give little paragraph synopses and organize them,” said Bruce Harmon, deputy director of U.S. Department of Energy Ames Laboratory and distinguished professor of physics and astronomy at Iowa State.

High temperature superconductivity was a breakthrough in the world of condensed matter physics because superconductors with higher operating temperatures mean less expensive cooling costs. 

Superconductors could one day be used to deliver electricity to commercial and private industries, but the technology is not quite there yet. 

The discovery of high temperature superconductors made the reality of superconductors in everyday life a little more hopeful.

“At the time, the web was not yet well-developed, so the communications were still very slow. You see, you send an article to journal, it will take a few months to be accepted and then published. So the information moved slow, on a much slower pace than it does now,” said Vladimir Kogan, adjunct research associate professor of physics and astronomy at Iowa State and scientist at Ames Lab.

“Initially, we sent this out to everyone who provided information about preprints — and so it meant that people who were not at the national labs, but provided us with information as a courtesy — with ‘High-TC Update’ as a courtesy,” Clem said. “This very quickly became international and the ‘High-TC Update’ became an extremely valuable resource to people, particularly in the Soviet Union and in the Soviet Bloc who had very poor library services.”

“It was just an incredible amount of work to read through those and make comments on these things so I appreciated what he was doing for most of the year. He did that for about 10 years we had that publication so that really put Ames on the map,” Harmon said. “He read all the papers and made comments on them and the thing that was terrifying to me was if John wanted to go to a meeting or something he would say: ‘Bruce, could you do it this week?’”

“High-TC Update” was most regarded for its “nota bene,” which is where people look in the book to see its most notable points. 

Clem put the preprints he found most promising in this section and was surprised one day to find the astute regard and seriousness on Nobel Prize laureate took regarding the “nota bene.”

“One time I reported on what I thought people would recognize as an absolutely ridiculous prediction … expecting that physicists would immediately recognize that this was absolutely ridiculous,” Clem said. “I got — I wouldn’t call it a hate mail, but a kind of bitter comment from P.W. Anderson, a Nobel Prize winner, saying, ‘How could you include that in ‘nota bene’?”

Clem, however, did not choose to publish “High-TC Update” or the fame or limelight but considered reviewing these preprints as part of his duty as a professor.

“I did this for many years, spent many hours, and I appreciate my wife’s patience with me, that I would be working until three in the morning doing this to meet a deadline for the next day for ‘nota bene,’ but I knew I was doing it as a service to the superconductivity community,” Clem said. “I knew that even though they wouldn’t know who I was, I knew that they would appreciate this.” 

Shoulders of giants

Although Clem said he did not have much contact with his thesis adviser, it is clear Clem takes well after John Bardeen, one of only four people to have won two Nobel Prizes  and the only one to have won two in physics.

“When I was a graduate student, I tended to be a very independent student. So my contacts with Bardeen were rather limited,” Clem said. “He was a very quiet individual. Everybody knew he was very quiet and he had the reputation of being so smart that when reverent people had a problem they couldn’t do, they would go into his office, describe the problem to him, and he would get out a 3×5 card, write the solution, and give it to them.”

Those colleagues who know Clem best describe his uncanny ability to always be right about a physics problem. Clem describes Bardeen as a very “mild mannered” and “modest man,” something that is also true for Clem regarding this gift for theoretical physics.

“He’s able to do long, long calculations. We are theoretical physicists, we are writing formulas, developing all kinds of conclusions from mathematics, and when I do it’s just inevitable that I make mistakes, so I come back and do it again and do it until I am sure that what I have is correct,” Kogan said. “John is able to do pages after pages of pages of long, long calculations and there are no mistakes whatsoever. He has a kind of incredible ability of that sort.”

“I remember one time I had told [Bardeen] what all I had done and he said, ‘I think you have enough here for a thesis.’ That was music to my ears, and so I began writing my thesis,” Clem said with a smile. 

“When various chapters were completed, I would send them  around the world, wherever he was visiting, and finally I had my Ph.D. exam in the August of 1965.”

A passion for music

For all his numerous accomplishments as a theorist Clem is also known for his gift for music. Clem’s colleagues  were equally eager to disseminate that Clem could have been a professional musician as they were to name Clem a world-renowned theorist in superconductivity.

“I have always been, throughout my lifetime, interested in music and when I was in my college days I played in the University of Illinois bands. I was a part of the Marching Illini and I sang mainly in my fraternity. When I became a graduate, I didn’t have enough time for that so I dropped music for awhile,” Clem said.

But music came back to Clem. He took voice lessons at Iowa State and participated in Music Antiqua, a group dedicated to playing antique instruments and performing music from earlier centuries.

“I sang with Music Antiqua. It was a group that performs in costume, and I had the costume of an English nobleman from the 1520’s. Seafoam green tights, a tunic, a nice hat, and a thing that looked like a big jewel in the middle,” Clem said, laughing heartily.

Clem emotionally recalled fulfilling a desire to sing all of “Winterreise,” a song cycle by Franz Schubert, with a fellow colleague in the department of physics who also played the piano.

“We had this opportunity to work on ‘Winterreise’ and it was a challenge for a pianist as well as a singer so I spent the whole year at my voice lessons getting ready for that,” Clem said. “It was a great opportunity, I’m really emotional about this, to get together with him to do that. We got up very early to do that, maybe five-o’clock in the morning to do that, so we went through the entire ‘Winterreise’ and really enjoyed doing that.”

During a workshop in Israel, Clem and his colleague performed three of the songs from “Winterreise” in front of a physics conference.

“I was doing an awful lot of travel and am so grateful that my wife stayed with me after all this time because. … it probably added up to two months I was gone during the year when you added up all the weeks,” Clem said.

A devoted husband

Physics and music were two loves of Clem’s life, but the third and most telling love of Clem’s life is the love he has for his wife. 

Judith Paulsen Clem, or simply Judy, has a brick on the Plaza of Heroines outside Catt Hall. 

She worked part time as a registered nurse before serving on the Board of Trustees of Mary Greeley Medical Center.

Judy’s life took a turn for the worse when doctors discovered she had a brain tumor. Clem now dedicates his life to superconductivity theory and being a primary caregiver to his wife. 

It is clear from the emotional way he talks about his time with her that only the deepest passion for physics could take him away from her side during the day time hours.

“Of course I spend time with her in the evenings on weekends, and I read to her and things of the sort. She has excellent comprehension and she has a great sense of humor. Very wonderful sense of humor and good spirits all the time, so she’s a joy to be with,” Clem said, both smiling and keeping tears in check. “Besides, I owe her a lot, because all she put up with for the rest of her marriage, so she’s built up a lot of credits during the time before she had the brain tumor. So I’m happy to be her primary caregiver so she’s doing very well.”

Clem himself is battling mesothelioma. 

As a young man Clem worked in a factory that handled asbestos before it was well known that asbestos caused cancel. 

Like his colleagues, Clem attributes his mesothelioma to working in the factory.

“Even though companies maybe knew there was a danger of asbestos they didn’t tell their employees about that. They didn’t tell people to wear masks or things of that sort, and I’m sure I breathed in a lot of asbestos dust. The asbestos particles have little prongs on these little fibers and you can’t cough them up. So they were in there for a long time before they start producing this mesothelioma,” Clem said. “It’s incurable, but it is treatable and so I’ve been on chemotherapy for the last two and a half years and the chemotherapy has arrested the progress of this.”

Taking things in stride, Clem said he was happy he had more hair than his father ever did, despite the chemotherapy.

“He’s doing very well — much better than statistics would predict,” Kogan said.


Celebrating a legacy

This year, Clem will receive the 2012 Institute of Electrical and Electronics Engineers Council On Superconductivity Award for Significant and Sustained Contributions to Applied Superconductivity. The award will celebrate the achievements of his work as a superconductivity theorist and recognize his contributions to the field of condensed matter physics.

Clem has spent most of his career as a Cyclone, worked under some of the brightest minds in superconductivity theory to have ever existed and has helped Iowa State build a legacy in excellence of superconductivity research.

“He’s been here for pretty much his whole career and he is, I would say without a doubt, the world’s leader in applied superconductivity theory,” Harmon said. 

“It’s exciting that he got that award. It’s a career’s worth of effort that goes into something like that.”