The world on a string

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Physicist Ashoke Sen, winner of the Fundamental Physics Prize, tells Janani Ganesan how the $3 million cash award hasn’t changed his commitment to research

Photo: Dijeshwar Singh

IN HIS nondescript office at the Harish-Chandra Research Institute (HRI) in Allahabad, theoretical physicist Ashoke Sen is hardly visible behind his iMac. He has been fiddling with his mathematical models undisturbed for years. Well, until he was awarded $3 million for his work. Then all media broke loose.

It is hard for anyone entering Sen’s sparsely furnished room to not notice the big, bright screen of the computer. A Wikipedia page on Von Neumann Entropy is visible. Later, the 56-year-old would clarify that with the advent of the Internet, the low funding for research does not affect theoretical scientists. That the Internet revolution for a scientist includes Wikipedia pages comes as a mild surprise.

When Sen received the call from billionaire Yuri Milner, the Russian entrepreneur and venture capitalist who set up the Fundamental Physics Prize (FPP), he was at a conference in Germany. This being the first year of the award’s institution, Sen had not heard about Milner. “You probably know more about him from reading online than I actually do,” Sen jokes. In fact, he couldn’t shake off the feeling that this might be a hoax. A week passed before he told his wife, Sunitha Rao, also a professor at HRI. Even HRI was in the dark until Sen’s bank manager called after the money was deposited into his bank account. The amount, almost three times that of the Nobel Prize, has monopolised public attention rather than the work of the nine awardees. Despite being the only Indian to have got the honour, the media barely mention Sen’s work in string theory before salivating over the cash prize. “I haven’t thought about the money. I still can’t comprehend it,” says Sen, not as a standard response but genuinely flummoxed by what a theoretical physicist living on campus would do with it.

To be fair, theoretical physics, not easily demonstrable or explainable, lacks glamour. “That is why the work going on in India is, perhaps, not that visible. Physicists like JC Bose and SN Bose deserved the Nobel,” laments Sen. “Even today, there is a lot of great work being done in the country in theoretical physics, especially in string theory.”

Paul Davies, in his introduction to Richard P Feynman’s Six Easy Pieces, nails why grasping theoretical concepts in the field poses a challenge: “Theoretical physics is one of the toughest intellectual exercises, combining abstract concepts that defy visualisation with extreme mathematical complexity.” Not all scientists have Feynman’s flair for simplification. Sen himself tries to explain his work in layman terms, but his alphabet belongs to an alien language — that of quantum theory and particle physics.

“If the Universe Is the Answer, What Is the Question?” asks the Nobel-winning physicist Leon M Lederman in the subtitle to his popular 1993 book, The God Particle. Physicists have chased the ultimate question with what is called the Standard Model. The model explains three kinds of forces among elements of matter — electromagnetic, strong and weak. But it leaves out the forces of gravity. String theory tries to give a unifying explanation, including gravity. “A testable string theory would eventually answer how the universe works, how it began and why it evolved to what it is,” says Sen. Would it explain existential questions too? “You’ll have to go to chemistry or biology for the origin of life,” says Sen.

String theory is currently untestable. It requires nine coordinates whereas equations usually are solved using three coordinates. Nor has a microscope of such fine resolution been invented to observe said strings. But neither did we have the capability to test the Higgs boson 50 years ago. “It may take more than a century for string theory to be tested,” says Sen.

FIVE DIFFERENT string theories have been circulating since the 1970s. Sen’s work, referred to as “strong weak coupling duality” — a paper he wrote in 1994 when he was a professor at the Tata Institute of Fundamental Research (TIFR), Mumbai, and published in the journal Physics Letters — helped conclude that the five were but different variations of the same theory. “For uncovering striking evidence… opening the path to the realisation that all string theories are different limits of the same underlying theory,” reads Sen’s award citation on the FPP website. Three other physicists have also been recognised by the FPP for their work in the field of string theory.

“I have met all but one awardee at various conferences,” says Sen, who travels to at least four or five international conferences in a year. A three-hour teaching session, three days a week, with a maximum of 15 postgraduate and PhD students leaves Sen with plenty of time to focus on his research — “Our IITs don’t do as expected in research because the faculty is so bogged down by teaching and administration. But funding for research has increased tremendously in India though it will take time for the results to show,” he says. Still, the HRI runs on an annual recurring budget of 10-15 crore, funded by the Department of Atomic Energy, “an amount”, says Sen, “sufficient for theoretical physics but not enough to fund one experimental project.” “In general, though,” he adds, “the situation is better. A few years ago, inviting someone for a seminar from another institute in India was difficult. We could not pay the airfare. Now that is possible. Also, any reasonable project proposal (except for a very expensive one) has a high chance of being approved.”

Tucked away from the chaos of Allahabad, right on the banks of the Ganga, HRI’s lush-green 60-acre campus is an idyllic setting for the long walks Sen likes to take with his wife. “Initially, he needed moral support, but now he is used to all the media and the photo sessions,” quips his wife, preferring to keep out of the conversation. Indeed, Sen diligently picks up his laptop from his office when we move to his house to take pictures. He understands that his workstation is needed to complete the picture, not as a pompous display but by habit of being exposed to media over the past few days. Rao’s paintings line the walls of their home. “My wife reads a lot more non-physics literature than me. She did all these paintings,” says Sen, pointing at the well-decorated walls. His leather sandals, thick rectangular glasses, and an occasional involuntary twitch, make him the picture of the retiring, avuncular scientist. It’s an image that belies the complexity and importance of his work.

Sen appears unruffled by his anonymity. A BSc from Kolkata’s Presidency College, an MSc from IIT Kanpur, a brief stint in the US for his PhD and post doctoral thesis and then back in the country at TIFR and then to HRI, Sen’s trajectory is seemingly conventional but not when measured by the reach and standard of his work. “Theories may be esoteric sometimes but their mathematical consistency is a powerful tool,” he says. Sen is devoted to his field, to collaboration with colleagues. Whatever the figure in his bank account, whatever the media flurry, he will be found in his office communicating with distant counterparts on Skype.

Janani Ganesan is a Correspondent with Tehelka.
janani@tehelka.com

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