Saturday, June 1, 2013

Interview of Prof.A.J.Legget, Nobel Laureate in Physics

Anthony James Legget is a famous scientist and a capable generous man, working in the field of fundamental physics. He is one of the leaders in the field of low temperature physics in all over the world. He has widely contributed in understanding the normal and super-fluid helium liquids and strongly coupled superfluids. He has also deep interest and insight in testing the foundations of quantum mechanics using condensed systems. His pioneering work in the field of superfluidity was recognized for Nobel Pize of Physics in 2003. He is an Honorary fellow of Institute of Physics (U.K.). He was knighted as “Sir” by Queen Elizabeth II in 2004 “for services in physics”. He was also elected a Fellow of Royal Society.
Sir Anthony James Legget is popularly known as Tony legget in the scientific community. He was born in 26 March, 1938 in a small town Camberwell of South London, England. At that time in England, studies of literature was considered as of great repute in common public and academicians. Anthony James Legget won a scholarship from Oxford University in 1954 to study Classics. After completing the degree, it was a time to rethink about the future of Classics and personal interest of him. Anthony Legget remembers those days in his autobiography written for Nobel Prize website as, “…. there seemed to be no objective criterion of what was correct or not, or even what was good work or bad (in Philosophy), and I felt in my bones that it was just such a criterion that I needed if I was going to pursue an academic career. I did indeed briefly consider the possibility of going into pure mathematics, but rejected it on the grounds that in mathematics, almost by the definition of the subject, to be wrong means you are stupid: I wanted the possibility of being wrong without being stupid - of being wrong, if you like, for interesting and nontrivial reasons. Physics seemed to fill that bill, and while I had zero formal training in that subject, the confidence which I had acquired from Fr. O'Hara in advanced mathematics led me to believe that that aspect of the subject, at least, would not give me major difficulty. So, in the early summer of 1958 I took my courage in both hands and applied to do a second Oxford undergraduate degree, in physics, following the anticipated completion in spring 1959 of my Greats degree.”
After completing his academics, he did his Ph.D. on "Some Problems in the Theory of Many-Body Systems", with Prof. Dirk ter Haar at Magdalen College, Oxford. His theoretical understanding of physics took shape here and blossomed. After completing his post-doctoral studies, he accepted an offer from the University of Illinois at Urbana-Champaign (UIUC) of the MacArthur Chair, in the spring of 1982  with which the university had recently been endowed.
Meher Wan got a chance to listen his invited lecture in Physics Department, University of Allahabad some years back. Prof. Anthony Legget is kind enough to answer the queries and questions of students and researchers of physics very promptly through email too. Here are the excerpts of the interview.
Meher Wan- Let me thank you on behalf of our readers for accepting my request to respond for an interview on your research, life and philosophy. It’s a matter of pleasure for us that you agreed to invest some time from your very busy schedule.
Your pioneering research work on super-fluidity was considered for the most prestigious prize of Science- “Nobel Prize of Physics-2003”. After Nobel Prize, how your life has been changed? What type of relax or responsibility do you feel after this prestigious prize?

Prof. A. J. Legget:  The main ways my life has changed are that-
 (a) I get even more invitations than previously to give popular talks, etc.
 (b) Even more people want me to write letters of recommendation for them.
 (c) I am continually pressed to express in public opinions on matters of which I do not know enough to have an informed opinion.

M. Wan- Let us peep in to your childhood, how do you remember your school days and Beaumont? Were you extraordinarily brilliant in your school days or you made these achievements by mere chasing your curiousness and intent for the quest about nature?

 A. J. Legget: Well, I remember that they used to give prizes for the best performance in about eight different academic subjects, and one year I got the prizes in all eight, which I believe was unprecedented. So I suppose that I did have a reputation for outstanding academic ability.

M. Wan- At your times in schools, one had to choose science or classics or arts as stream of study in his/her very early stage of studies. When you came to Allahabad, India in a Science Conclave, you revealed that primarily you have chosen Classics and literature as your study majors. What were the reasons for choosing classics not science still when your father was a science teacher?

A. J. Legget: Actually, I think my father was steeped in the attitude which was common in Britain at that time (the early fifties, pre-Sputnik), namely that classics was the most "prestigious" subject and science right at the bottom of the pecking order. Certainly he was quite happy to see me go into classics.

M. Wan- After spending five years in studying classics, what was the motivating force for opting science and specially physics?

 A. J. Legget: Actually it was a good deal more than five years (about 5 at high school, then 4 at Oxford if you count the part spent on ancient history and philosophy).The reason for my shift was, first, that I was too unimaginative to think about any career other than an academic one, and secondly that I became convinced that, rather than working in a subject such as philosophy, where there seems to be no clear objective criteria of what constituted good work or bad, I wanted to work in a discipline where Nature herself could prove me right or wrong.

M. Wan- How did the previous study of classics help in your further career? Did you imagine at that time, that you will do so nice in physics after spending too much time in other subjects?

A. J. Legget: I realized that my comparative age was some disadvantage, but I felt that my experience of studying philosophy, in particular, might compensate for this. And indeed I have found it extremely helpful, in particular in that I suspect I am much more skeptical than many of my colleagues about the "established" wisdom and the reasoning behind it.

M. Wan- At the time of your postdoctoral work in University of Illinois, John Bardeen and some other impressive experimental physicists were working there. How did they influence you in the process of being a better researcher?

A. J. Legget: Like many others, I did not find John the easiest person in the world to talk to, but he and Leo Kadanoff played a crucial role in my career by suggesting the problem which led indirectly to my work on superfluid 3-He.
I got more out of my interactions with David Pines (my formal postdoctoral adviser), Leo and Gordon Baym, as well as with the many bright postdocs who were at Illinois at that time.

M. Wan- You have travelled around the globe. What is the status of education in developing countries? What type of modifications you will suggest for the betterment of education and teaching?

A. J. Legget: I'm not sure that one can make any generalization which will cover   India or Brazil on the one hand and Haiti or the Central African Republic on the other. But I think that one rather common feature of   education in many D.C's tends to be an exaggerated respect for authority (including that of Nobel laureates!).I think it is crucial that teachers in such countries feel able to admit that they don't know the answer to a question without fearing that students will lose respect for them.  Also, what is missing in at least some cases, e.g.in the West African   country with which I am familiar, is very basic technical skills, and this  is something that I feel that visiting teachers from the developed world  tend to forget-it isn't much use students being up with the latest  fashions in sociology of science if they can't repair the electrical  generator when it breaks down!

M. Wan- Quantum revolution influenced approximately all fields of sciences. What are the limitations of quantum mechanics?

A. J. Legget: We don't know, and much of my research has been devoted precisely to trying to design experiments to test this.

M. Wan- What do you say about the future of String theory or superstring theory?

A. J. Legget: Nothing. It is too far from real-life experiment for me to have an opinion.

M. Wan- Many theoretical physicists often wished to have more command on mathematics to do batter physics. Have you felt this at any juncture?

A. J. Legget: Yes, somewhat. But I don't think the lack of a better mathematical education has prevented me doing the really crucial things I have tried to do.

M. Wan- Feynman made a hypothesis at that time, that Fundamental Physics will be much tougher after some years and that state of saturation will be dominating reason that researchers will shift their interests towards other sciences. At what extent are you concerned with this statement?

A. J. Legget: I suspect that Feynman is right, in that if and when we get a "Theory of Everything", physicists will become intellectually restless. But I think they will probably change the questions they are asking so that the "theory" no longer seems so satisfying. Alternatively, as is already happening to an extent, they will try to use the methods of physics to address problems in other fields (psychology, economics...).

M. Wan- You are a scientist and you have faith in religions too. According to you, how do the science and religions connect with each other? Where are the common platforms of science and religion?

A. J. Legget: I am not in fact myself religious, but I see no objection to some of   my colleagues being fervent believers while remaining practicing scientists. The way I view "religious" statements is as a sort of third dimension in the space inhabited by the "fact-value" dichotomy, so they do not compete with the statements made by science.

M. Wan- According to you, which type of important developments and revolutions, will occur in the field of science in near future?

A. J. Legget: If I knew, I would be there already! My best bet would be on a totally novel approach to the "arrow of time".

M. Wan- What message do you want to convey to the students and budding researchers through this magazine?

A. J. Legget: Follow your own curiosity, and don't be put off if everyone around you tells you that the answers to the questions you are asking are obvious or trivial. Remember Einstein and the equivalence principle-
   “Sometimes the really deep questions are so simple as to seem stupid!”

 It was very nice to have communication with you, Sir. I feel that youth will be inspired by your thoughts. 

Thank you very much Sir.