JIM LEHRER: Now, the Nobel prize in physics, and to Ray Suarez.
RAY SUAREZ: Today's prize went to three scientists for their work in quantum physics, specifically how atoms and electrons behave in extremely low temperatures. Alexei Abrikosov and Vitaly Ginzburg were honored for their theories about superconductivity. That occurs when electrical current is able to pass through metal without resistance. Tony Leggett was given his award for work on super fluidity. That's what happens to liquid helium when it's chilled to a temperature near absolute zero. Tony Leggett joins us this evening from the University of Illinois at the Urbana-Champaign campus, where he teaches. Welcome to the program and congratulations.
TONY LEGGETT: Thank you.
RAY SUAREZ: The Nobel citation released today says that you and your co-recipients won the award for decisive contributions in super conductivity and super fluidity. You worked on the second. What is super fluidity.
TONY LEGGETT: Super fluidity is actually a complex of phenomena which sometimes are observed in liquids under conditions of very low temperature. Perhaps the most striking phenomenon which is most easily observed in Helium 4 is that the liquid can actually flow through very small pours or capillaries without apparent friction but there are a whole lot of other phenomena associated with it. For example, if you put super fluid helium in a bucket and rotate the bucket then unlike water it won't retain with the bucket. It will stay at rest in the laboratory.
RAY SUAREZ: And what is super conductivity?
TONY LEGGETT: Well from a modern point of view, a theoretical understanding is that super conductivity is basically super fluidity occurring in a charged, an electrically charged system. The most obvious consequence of that is that current can flow in a super conducting wire without apparent resistance. Again there are many other phenomena but that's probably the most spectacular.
RAY SUAREZ: How is it that you and other scientists like your co-winners got so interested in seeing what happens to materials when they're super cold, hundreds of degrees below zero?
TONY LEGGETT: Well, I think it's in this regime that one sees most spectacularly the effects of quantum mechanics which of course we all believe to be the right theory to describe individual atoms and electrons but we see its effects where it's applied to huge assemblies of atoms and electrons and sometimes these can give rise to these quite bizarre forms of behavior.
RAY SUAREZ: Well, you mentioned bizarre forms of behavior. I was just trying to remember my middle school physics where you were told there was always resistance when current passed through material. You were told that eventually atoms stopped if you made them cold enough. Aren't the things you're learning showing that these laws don't really apply once you make things super cold.
TONY LEGGETT: That's right. In the super fluid or super conducting phases really that doesn't apply.
RAY SUAREZ: So tell me a little bit more about this work. Physicists, theoretical physicists like yourself are often shown as people at chalk boards writing equations, Greek letters, filling entire boards and trying to puzzle out the answers. If I was to visit you at the University of Illinois, would I be more likely to find you doing that or in a lab with something that's 400 degrees below zero?
TONY LEGGETT: I think frankly if you were to find me in a lab of that kind, my experimental colleagues would be doing their best to make sure I didn't touch the apparatus.
RAY SUAREZ: So watching what happens but not doing it yourself?
TONY LEGGETT: Yes. Yes, I think that would be the wise thing for them to do.
RAY SUAREZ: Now, once we gain a greater understanding of what you've been working on for almost 40 years now, what will it allow us to do? Are there scientific discoveries, breakthroughs, waiting in the wings that are waiting for refinements in our understanding of super conductivity and super fluidity?
TONY LEGGETT: Yes, I think there certainly are. A major puzzle today is the phenomenon of high temperature superconductivity, which occurs in a certain class of materials at about room temperature. The basic way in which that kind of super conductivity works is not at all clear. It may be the same as the old-fashioned superconductivity, or it may be something rather different. Right now we just don't really understand that. But I personally think that a much bigger and more interesting question is whether in fact we can go on applying quantum mechanics forever even up to the level where it appears to conflict with our everyday common sense. And I'm ... I have been particularly interested in trying to devise or promote or analyze experiments which may shed some light on whether that's true or not. And I have to say that experiments in the last few years seem to have shown that it is true at least up to a remarkably ... a level remarkably close to everyday life.
RAY SUAREZ: It sounds like you're still excited by the work that you do and feel when you go into work in the morning that there's still a lot of things to find out.
TONY LEGGETT: Oh, yes.
RAY SUAREZ: And how does it work when you win a Nobel with collaborators? Are you considered people who have been working on a similar area even if you haven't literally been working together?
TONY LEGGETT: Well, yes, Professors Abrikosov, Ginzburg and myself have all been working this general area of quantum, spectacular quantum effects in many atom systems at very low temperatures. But we haven't formally collaborated. In fact we really had no chance because their work was done in Moscow in the '50s.
RAY SUAREZ: Your work was done quite a long time ago according to the citation. Do you really feel that you've been rewarded for a lifetime's work or a particular period of things that you've done over time?
TONY LEGGETT: Well, the citation was specifically for the work on super fluid Helium 3. That was done primary I think perhaps the most important part of that work, the one which had the most impact was done in the early '70s and I did continue to work on that for the next few years. Since then I've been interested in a variety of topics and certainly some of the work that I've been able to do in those years will also stand up to the test of time.
RAY SUAREZ: Congratulations again, Professor Leggett. Thanks for being with us.
TONY LEGGETT: Thank you.