Leon N. Cooper


Interview, July 2003

Interview with Professor Leon N. Cooper by freelance journalist Marika Griehsel at the 53rd meeting of Nobel Laureates in Lindau, Germany, 30 June-4 July 2003.

Professor Cooper, who was attending the Lindau meeting for the fifth time, talks about problems with predicting the future, unforeseen practical applications of superconductivity (2:12), and his present work in neuroscience (6:31). Cooper also provides some advise to young students (14:24) and talks about the thrill of solving problems (16:29).

Interview transcript

Professor Leon Cooper, welcome to Lindau. It’s very nice to have you here.

Leon N. Cooper: I’m very happy to be here. Nice cool weather you have.

I know. I believe it’s the fifth time you are visiting Lindau, and this very particular meeting where scientists and young scientific students meet. What is it that makes you come back for the fifth time?

Leon N. Cooper: Actually I didn’t remember that it was the fifth time. Each time is different. This time in particular I’m interested because it’s a meeting of medicine – doctors and physiologists. I’m a theoretical physicist that has been working in the areas of neuroscience, and basically I’m on a mission to convince the medical and the physiologists that a theoretical physicist can make a contribution to their field. Basically, to be more direct, theory has played an enormously important role in physics, and physicists understand the interaction between theory and experiment. But this is relatively new in neuroscience, and what I would like to do is to present an example of how theory can be useful in neuroscience. And we have lots, I think we have a very convincing case, but we’ll wait to see what the experts say.

That’s part of your talk tomorrow, I believe.

Leon N. Cooper: That probably is my talk tomorrow, because what I would like to show is how a theoretical structure can lead to new experiments that discover new phenomena that eventually can be of use. We can never be totally sure of what the usefulness will be in advance. It’s one of the mistakes people make about science. Scientists are really no better at predicting the usefulness or lack of usefulness of what we do than anyone else. Because basically none of us can predict the future. However, statistically, the uses are enormous.

If we just turn the clock back a little bit and look backwards to what you have achieved, when you were about 28, 27 years old. Could you have imagined what you then found out, what use it would have at that time?

Leon N. Cooper: That’s a good question, because we were interviewed over and over toward the end of the 1950s, and the first question was: What are the practical applications of this great theoretical breakthrough? We listed all kinds of things like superconducting power lines, and things of that kind, and some of them are actually coming to pass. Yes, fifty years later, but the most important by far is what’s called the superconducting quantum interference device, based on what is known as the Josephson effect, which we didn’t even know existed at the time. That came just a few years later, and that’s now, it’s a way of measuring magnetic fields that’s far more sensitive, and it’s just used everywhere. It’s used in all kinds of devices, all kinds of electronic devices. And you see, that’s the amusing thing. It was a consequence of our theory, but it wasn’t one that we … You know, I wish I had foreseen it, but then I sometimes kick myself for not having foreseen it, but we didn’t. At least, I didn’t. It’s typical of what happens in scientific discovery, that you don’t necessarily foresee all of the consequences of what you yourself have done.

There’s a very practical use. For example, there is an electric train, I believe, grown on magnetics.

Leon N. Cooper: Yes, that was the kind of thing that we thought of, but so far that hasn’t been done. That would be regarded as an obvious application. This was a much more subtle application and it just hadn’t been thought of. Oh, I could give you many examples. For example, the famous nuclear physicist, Rutherford, in the twenties, was reported to have said that the idea that you could get energy out of the nucleus was moonshine. And he was probably the greatest nuclear physicist alive at that time.

The studies that you …

Leon N. Cooper: It makes one humble.

Is it important to be humble as a scientist?

Leon N. Cooper: I wouldn’t say that, we’re all pretty arrogant.

But in light of what application that you couldn’t think of, that’s coming up through …

Leon N. Cooper: I suppose it would be prudent but that doesn’t mean that most people are. I’m exaggerating a little bit. Sure, you certainly should be cognisant of the fact that you can’t predict the future. It’s very hard to predict the future, and often there are just unexpected things that happen, that we don’t foresee. This is one of the reasons that when you do scientific work, and a current example is stem cell research, which, you know, is enormously controversial. We have politicians saying that you should do this, you should do that, you can get better results doing this, where’s the good doing that. I mean, it’s ludicrous. The experts don’t know. The only thing you can really say is that nobody knows exactly what the fruitful paths will be, or if there will be a fruitful path. So what scientists do is to try everything, and see what happens. I am reasonably convinced that there will be success in some direction or another, but I don’t think anyone could predict at the moment. That’s another … I’m sorry, obviously I don’t give you any chance once I get going. That’s one of the reasons that it’s very dangerous to constrain research from above. Administrative agencies, they try to say do this and don’t do that and don’t do the other thing. They can’t predict any better than the scientists can, that’s just very dangerous. What you really should do, in my opinion, in large part, is you should put your money on your best racehorses, and then let them run the race they think is best. It’s not perfection but probably will work better than anything else.

The work that you’re doing at the moment is to see the way the mind works, to simplify it. What is the … you want to have a talk tomorrow, you’re on a mission, you say, but what can you see in the future, what uses can this have?

Leon N. Cooper: First of all there are an enormous number of mental diseases of all kinds. Everything from mood diseases to schizophrenia, to all kinds of things, and hopefully, if you understand how the system works, you would be able to do something about repairing some of those problems. And I have a personal opinion that many of the worst problems might be a little easier than people expect, because it’s so easy to alter moods. We have various conceptual reasons for believing that things like memory consolidation and moods are influenced by overall factors and so you could make therapeutic interventions. We don’t know, of course, how effective they will be or whether they would work. You would never know before you actually do it, but there’s every reason to believe that you could have substantial help in various mental diseases, and then of course there’s the intellectual challenge of seeing how a biological system, how neurons put themselves together to process information and eventually how we achieve our mental states and so on. It’s an enormous intellectual challenge, and you don’t really know what the consequences are, but we can say from a past history that there will be consequences, we can’t foresee them all, and the chances are that some of them will be of immense importance.

It obviously still gives you a lot of satisfaction to do this work. What are the biggest challenges on a daily basis?

Leon N. Cooper: Getting out of bed in the morning. Getting enough caffeine into use so your mind starts functioning.

But interaction with other students, other scientists? How do you see, on that level, is that a challenge, to build teams …?

Leon N. Cooper: It’s something I enjoy very much. I really, really enjoy … I don’t subconsciously build teams, they evolve, and I just work with different groups of associates and students on different problems, and some of them are seemingly very profound, and others are relatively straightforward. For example, I’m enormously pleased that we’ve just invented a new way to build a sonar system. It seems to be an enormous improvement over current systems, and it’s not really my field, but I just love problems of that kind. I love, once I get into them, I’m very interested, and I don’t think you can really work by feeling I’ve chosen a problem that’s enormously important. You are sort of a led from one thing to the other, and of course you try to work on things that will make a difference, that have significance, you don’t want to waste a lot of time on things. But still you’re led sometimes in unexpected directions, and something that you wouldn’t have thought would be interesting suddenly becomes intriguing. It’s just intriguing, you want to solve it. Basically, you know, many scientists like I have been characterised as a problem solver. I get fascinated by a problem and I want to solve it. It’s a challenge, it’s not so much a challenge really, it’s an enormous pleasure to work on a problem, to work with people and then to feel your way through it. It’s the same pleasure, I think, as probably doing a crossword puzzle, or something.

Do you think that the prize gave you a better opportunity to do your work, the Nobel Prize, back in 1972?

Leon N. Cooper: Oh sure, it gives you additional opportunities to get financing, to get people to make foolish statements, people are always asking you to express your opinions about things you don’t know anything about. You have to be a little careful. But sure, of course it gives you opportunities, and I think used properly, carefully, it’s a tremendous advantage, a tremendous advantage. Also, it’s somewhat of a burden, because in the sense that people look at what you do differently, they judge it differently. There’s always the question of what are you going to do next. If you worry about that you just can’t do anything, and basically you just do next what is next, and you don’t worry about it too much. I mean, not every problem you work on is of a Nobel Prize calibre. It would be ridiculous to even think that way. Sometimes it evolves, sometimes it doesn’t.

I believe that you have also, for example, spoken out on political issues. I have seen letters that you have signed, for example, in the problems back in the 1980s in Poland and so on. Do the Nobel Prize winners have a special responsibility, do you think, as well, in certain fields?

Leon N. Cooper: I think I have a responsibility, just as every other citizen, to express myself on issues, if I feel I have any competence, or have an opinion, and I don’t do it too often but I sometimes do, and if having the Nobel Prize helps then that’s fine. But, sure, but although you do, again, you have to be careful because you can easily abuse the privilege, and find yourself … I mean, I’m asked to sign things that I know nothing about whatsoever. And I try to avoid that.

Do you think the climate for scientific studies and for scientists in general is better in the United States than in Europe? There were some talks about that today, briefly mentioned …

Leon N. Cooper: I think probably it has its ups and downs, but for many years it was very good in the United States. I think Europe is coming up in certain fields. It’s a question of support, the openness of universities, the freedom to do research, the absence of stifling influences from above, and I think the United States has been freer in that respect. But we have our bad periods, too. There are always politicians, people are the same, there are always politicians, there are always people who will stifle research by saying you should do one thing and not do another. But it’s just harder to do in the United States, because in the United States there are so many centres of power that it’s a little more difficult, but still the agencies in the United States that provide the money for research have enormous influence and they can be stifled by the Congress. The Congress is often trying to do that. The most recent example is stem cell research. But there are always the po … you know, talk about arrogance. You have politicians literally telling scientists what the best way to do their research is, which is something even more than ludicrous, wouldn’t you say?

What would your advice be to a young scientific student who would listen in to this interview eventually, on the internet?

Leon N. Cooper: I think that any person who is interested in science and is willing to work and to have the discipline should do it. Advice in what respect? Should they go into science, or should they … what country should they go to?

If you have these kind of from above and lack of money situation, control, it’s not only that you maybe have to do your scientific studies, you also have to take another fight?

Leon N. Cooper: It’s not that bad. The situation … What would be more accurate is to say that the situation has its ups and downs, like most of history, and some periods are a little better, some periods are a little worse. It’s just like the general economic environment. There are some areas in science that become hot, and if you get your PhD there you have a hundred jobs waiting for you, and in other areas you can’t find a job, and five years later it’s just the reverse. It’s somewhat aggravating, but it’s not that different from the economics of the entire community, but I think the main thing is that there are enormous opportunities in science, and for people who can do it and are willing to do the work there is almost always something. But again, there may be some fields that suddenly become over-populated, and some areas that suddenly become less fashionable. It’s unfortunate because it takes, it’s a long-time commitment to become a scientist, and you may go into an area that is not fashionable by the time you get out of it. But I don’t know what to advise about that. If I were, as far as national policy is concerned, my own feeling is it should be kept on a steady course, and not go back and forth with fashions. But politicians don’t listen to that, either.

We’re coming to the end of the interview. What is maybe your greatest memory from your time as a scientist? Is there one particular memory that you would like to share with us?

Leon N. Cooper: I suppose my greatest memories are of working together on some of the major problems that I’ve solved with other people and realising that I had the solution. It’s simply enormously exciting, but you know, I would almost say that some of the greatest pleasures I’ve had are in smaller problems that no-one has ever heard of, that were just so exciting. The thrill of having just mastered them, but I suppose the quick answer is that I can’t come up with something that sounds like the major major memory to me. Do people, when you ask that question, do people immediately have a memory?

Not necessarily. It could be anything. It could also be a very long working night in the lab.

Leon N. Cooper: Oh, I see, I see.

Something as you said, a small problem …

Leon N. Cooper: I remember once when we were working on the theory of superconductivity that we were absolutely baffled by one particular problem, and I had this very complex calculation in my head, so I could just do it over and over again in my head, and I was at a concert in the University of Illinois, by a musician who is the brother of Virgil Partch, who is a  cartoonist, Harry Partch, but I won’t go through all that. Anyhow, in the middle of the concert, I saw that there was a whole thing that I had left out, and the way it was is that it was another term that was equal to the term that we understood. But I couldn’t work out the sign, because there are about five signs. I didn’t know if it was plus or minus. If it was plus then we would have exactly the right number, and if it was minus the entire effect would disappear. I couldn’t do that, I just could not get the sign. A sign is a very hard thing because it changes, and I remember going home and going over and over and over and over, and yes, it was right, it came out as perfect. So that was a good memory. I called it, that was really playing roulette with the family fortune. Double or nothing.

So you were happy then to announce it to your wife …? Did you?

Leon N. Cooper: Yes, but mostly to my colleagues.

Thank you, Professor Cooper and have a very good stay here in Lindau. Thank you.

Leon N. Cooper: Thank you very much. Nice to talk to you.

Did you find any typos in this text? We would appreciate your assistance in identifying any errors and to let us know. Thank you for taking the time to report the errors by sending us an e-mail.

To cite this section
MLA style: Leon N. Cooper – Interview. NobelPrize.org. Nobel Prize Outreach AB 2023. Wed. 29 Mar 2023. <https://www.nobelprize.org/prizes/physics/1972/cooper/interview/>

Back to top Back To Top Takes users back to the top of the page

Nobel Prizes and laureates

Fourteen laureates were awarded a Nobel Prize in 2022, for achievements that have conferred the greatest benefit to humankind. Their work and discoveries range from paleogenomics and click chemistry to documenting war crimes.

See them all presented here.
Nobel Prizes 2022

Explore prizes and laureates

Look for popular awards and laureates in different fields, and discover the history of the Nobel Prize.