E.C.G. Sudarshan, a noted theoretical physicist and a former director of the Institute of Mathematical Sciences, Chennai, has passed away at the age of 86 in Texas. His research interests spanned particle physics, quantum optics, quantum field theory, quantum information theory, gauge theories and classical mechanics.
Sudarshan was born in a Christian family from central Travancore in 1931 (he would convert to Hinduism about two decades later). He received his master’s degree from Madras Christian College in 1951. As he later put it, at the time, Homi Bhabha could not tolerate physicists studying quantum field theory anywhere in India outside of the Tata Institute of Fundamental Research, Mumbai. Given Sudarshan’s interest in the subject and, more importantly, his promising mastery of it, Bhabha invited him to join them.
Once there, a chance meeting with the American physicist Robert Marshak led Sudarshan and his young wife to start a long voyage by ship to take up graduate studies at the University of Rochester, New York.
In the 1950s and 1960s, the cutting edge of physics was to be found in the study of fundamental particles. Cloud and bubble chambers around the world were churning out reams of data. Faint particle tracks embedded in photographic plates contained the secrets of the way the universe was built. Poring over such information, Sudarshan was able to formulate the V-A theory of electroweak interactions, which describes a set of interactions among particles that are affected by the electromagnetic and weak nuclear forces of nature.
Marshak was justifiably wary of publishing a theory with such remarkable consequences, so it was subsequently publicised via the proceedings of a conference in Italy. He also facilitated a discussion with Richard Feynman and Murray Gell-Mann, who subsequently published a paper on the topic. In 1956, Chien-Shiung Wu’s experiment showed that a hypothetical law of nature that physicists had long thought to be true doesn’t always hold, that sometimes some natural processes break the law; the V-A theory proved to be instrumental in understanding this violation.
Subsequently, V-A theory would be a key component of the overarching theory of weak interactions flushed out by Sheldon Glashow, Abdus Salam and Steven Weinberg, for which they would receive the 1979 Nobel Prize in physics.
Sudarshan received his PhD from Rochester in 1958, went on to Syracuse University, came back briefly to Rochester and eventually settled down in Austin, Texas, in 1969.
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When I think of Sudarshan, the first thing that comes to mind is a picture of him sitting at home, on the recliner, watching teleshopping channels or soap operas on TV, a notepad in hand, calculating away on a problem that we would have discussed earlier in the day.
Sudarshan was severely diabetic; this often meant that students had to give him company when his wife was away in India. It was a good idea to have someone around at night in case the insulin dosage was not accurate. I would not let those opportunities go by at all while I was a student with him. At home, late into the night, he would show me by example that 99% of the effort to unlock the deepest mysteries of nature would be inescapable drudgery. One has to put pen to paper and perform the calculations, often through the night.
The single most important thing I learnt from Sudarshan was the sheer joy of figuring something out. Prizes may come and go, Nobel or not, and recognitions would follow whether welcome or not. No-one could take away from the joy of wrapping up a calculation and finding something new.
During lectures, Sudarshan was not the most inspiring teacher. He had a relatively disconnected way of speaking, often digressing into sub-topics and connected areas because he knew them all in great depth. But if you paid attention, there were always deep insights couched in cryptic metaphors and analogies, which, to some time, made each lecture more than worth its while. It was doubly sweet that some of those metaphors were based on cows and, and coconut trees, of the sort that only someone from Kerala could really appreciate.
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There has been quite a lot of discussion, especially in India, about whether Sudarshan was denied a Nobel Prize. In my opinion, there is no question that he deserved the prize. In fact, he should have been duly recognised for his seminal contributions to the Standard Model of particle physics, quantum optics, open quantum systems, the quantum Zeno effect and field theories of tachyons.
But maybe that was the problem too. Maybe each committee felt that Sudarshan’s contribution was more seminal or significant in an other field, so the prize should be given for that instead. This would have made it easier for officials to give the prize in that particular field to other individuals who had made singular contributions and continued work in the same area. One can speculate that, as a result, the buck was simply passed around.
To me, Sudarshan’s contributions to theoretical physics went beyond what a single prize committee could fully appreciate. More importantly, it remained true that the greatest reward he could have received was the joy of discovery.
Anil Shaji is an associate dean at the Indian Institute of Science Education and Research, Thiruvananthapuram. He received his PhD from the University of Texas, Austin, under the supervision of E.C.G. Sudarshan.
With inputs from Sunderarajan Padmanabhan, India Science Wire.