World-renowned physicist E.C. George Sudarshan died of natural causes this week at the age of 86. A professor of physics at The University of Texas at Austin from 1969 to 2016, he made many important contributions to theoretical physics.
Ennackal Chandy George Sudarshan was born in Kottayam, Kerala, India on Sep. 16, 1931. He received his Ph.D. degree from the University of Rochester in 1958. He then moved to Harvard University to work with Julian Schwinger as a postdoctoral fellow. After serving on the faculties of the University of Rochester and Syracuse University, he settled at UT Austin in 1969.
Sudarshan received many honors and awards, including the Padma Bhushan (Order of the Lotus) presented by the president of India (1974), the Bose Medal from the Indian National Science Academy (1977) and the Dirac Medal (2010).
Working with his Ph.D. advisor Robert Marshak, Sudarshan created the V-A theory of the weak force, a discovery that was crucial to the unification of the weak and electromagnetic interactions by Steven Weinberg, Abdus Salam and Sheldon Glashow, which in turn led to the 1979 Nobel Prize in Physics.
Along with Roy Glauber, Sudarshan developed a quantum mechanical description of light that would become the foundation of a new field: quantum optics. Glauber went on to share the 2005 Nobel Prize in Physics for that work. (SEED magazine recounted the controversy surrounding that year's Nobel in Physics.)
Sudarshan and his graduate student V. K. Deshpande first proposed the existence of particles called tachyons that would violate Einstein's theory of relativity by travelling faster than the speed of light. They would also have the bizarre consequence of allowing signals to be received by an observer before it was actually sent, violating the principle of causality. So far, no experimental evidence has been found to support their existence.
Update: Funeral services for George Sudarshan will be held on Thursday, May 17th, 2018 in Beck Funeral Home, 15709 Ranch Rd 620 N, Austin, 78717. From 10:30 a.m. - 11:30 a.m. will be the Hindu Ceremony, followed by Viewing from 11:30 a.m. - 1:30 p.m. and a Cremation Ceremony at 1:30. Read more about his life on the Beck Funeral Home site.
Comments 4
My PhD Thesis, "Quantum theory of charged-particle beam optics" originated from the following Paper:
R. Jagannathan, R. Simon, E. C. G. Sudarshan and N. Mukunda,
Quantum theory of magnetic electron lenses based on the Dirac equation,
Physics Letters A, 134 (8-9), 457-464 (January 1989).
http://dx.doi.org/10.1016/0375-9601(89)90685-3
https://www.sciencedirect.com/science/article/pii/0375960189906853?via%3Dihub
Further details at:
http://SameenAhmedKhan.webs.com/thesis-quantum-theory-of-charged-particle-beam-optics.html
With warm regards + best wishes
Sameen Ahmed KHAN
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Dhofar University
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Professor Sudarshan made great contributions to the academic field of physics as well as to the development of the university. His excellent services during his term of office at the university will be greatly appreciated by his colleagues, students and friends.
This is indeed sad news. I took undergraduate QM from Dr Sudarshan in the early 80s. During one lecture one of the other students commented on his fish tie. After all these years I remember that anecdote and his soothing and knowledgeable voice. He will be missed.
Dr. Sudarshan was a soft-spoken and gifted teacher with a knack for storytelling that would help us students connect with the equations. He taught one of the graduate classes in quantum mechanics when I was a student at UT Physics. From time to time, he would step away from the black board and give us an analogy to illuminate the meaning behind the math.
In one of his lectures, he was explaining a model of how wavefunctions evolve over time (using the "time evolution operator," U(t) = exp[- i 2pi H t / h] ). The idea, roughly, is that if one appreciates the full initial state of an isolated system, then that's mathematically equivalent to knowing what state it will be in at a future time. So if we look at something now and it does not get affected by external interactions, then we can also visualize its future configurations.
Dr. Sudarshan took a pause from the equations and recounted a story from the Hindu epic, the Ramayana by Sage Valmiki. The prince Lakshmana was departing from the kingdom for 14 years of exile, along with his brother Rama and Rama's bride Seetha. As Lakshmana was taking his mother's blessings, she gave him words of instruction and comfort:
"Know Rama to be [your father]. Look upon Seetha ... as myself."
(Ramayana, Ayodhya kanda, ch. 40, v. 9; https://sanskritdocuments.org/sites/valmikiramayan/ayodhya/sarga40/ayodhyaroman40.htm .)
The passage is quizzical. Why envision a young couple as an old couple?
Dr. Sudarshan said that this passage sometimes reminded him of the time evolution operator. In some ways, he said, Lakshmana's mother seemed to be telling her departing son: maybe, during your years away, you will sometimes find yourself longing to see your beloved father and mother again. That's okay. When that happens, look upon Rama and Seetha. In this young couple you can inherently see an elderly couple, connected between their states by the passage of time.
I thought it was delightful that he suggested this connection. Looking back, I see now that his mind was also connecting two concepts separated by time: a revered ancient text and a mathematical model from modern physics.
I'm grateful that I could be in his classroom.
Cyrus F. Bharucha
(Ph.D, UT-Physics, 1997)