One Hundred Reasons to be a Scientist

HOW I BECAME A SCIENTIST Roddam Narasimha Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India

It actually started at home. My father was among the early graduates in science in the small town he came from, and went on to study with the great Indian physicist Meghanad Saha, who was then teaching at Allahabad (more than a thousand kilometres from home). Returning with a Master’s degree, father taught at Central College in Bangalore, and, in his later years, wrote extensively about science in Kannada, the language of this part of India. He taught me very little physics or science directly, but his example and attitude—scientifically modern, socially liberal and culturally conservative—taught me something more basic, namely pride. My mother did not go to school beyond age ten, but she was an extremely well read and cultivated person— also proud. In the prayers she taught us to recite before going to bed the only things © Courtesy of Roddam Narasimha that we asked from God were intelligence and knowledge. At school I was fortunate to have some great teachers. One of them managed to get the late C. V. Raman, Nobel Laureate, to visit us. Raman was then the biggest name in Indian science, and he spoke with such wit and verve about his work that he had the audience in the palm of his hand—both kids and teachers. Mr. KVR, the teacher who arranged the Raman visit, also taught me to value writing—briefly and honestly. In those numerous examinations we used to have, there were often questions of the kind ‘How many planets are there in the solar system?’ I would just answer: 9, and would be severely rebuked by my other teachers for not naming the planets as well. This I thought was unfair, for the question had not asked for the names. Mr. KVR stood by me on such occasions, and so grew a bond between us—never personally close, but full of affection on one side and regard on the other. But another teacher became personally close, and often took me and a few other students out—for coffee, snacks and long chats. He once casually presented two books to me. One was the Lives of Great Scientists, and it opened my eyes to the strange intellectual world of (western) science that I immediately found fascinating. The other book was a Kannada trans-creation of Lewis Carroll’s Alice in Wonderland, which I fell in love with. How did Mr. BLA know so unerringly what books would make an extraordinary impression on me? By the time I was to enter university in 1949, physics was one thing that I was seriously thinking of doing, but the vast (bloodless) political and social revolution that was then sweeping south India made this impossible. I eventually went to the Government Engineering College at Bangalore to study mechanical engineering. But the most inspiring event of those years was a visit I made to the Indian Institute of Science (IISc) when they had an Open Day.

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In the quadrangle of the Department of Aeronautical Engineering (which had just recently been started) stood a lovely, World War II Spitfire, loaned for the occasion by the Indian Air Force. That was my first close encounter with an aircraft, and it opened another world for me. What struck me at that time was how smooth and graceful the exterior of the Spitfire looked (in particular its beautiful elliptic wings), but how complicated it was if I looked at the insides—which seemed like a jungle of cables, pipes, ducts, valves and so on. It seemed astonishing to me that beneath those graceful curves and surfaces (which I took to come from mathematics) lay hidden a bewilderingly complex technology—and I marvelled at those extraordinary people who had apparently mastered both. So when I got my bachelor’s degree I wanted to do aeronautics, but this was very unfashionable at the time. At my father’s suggestion I consulted a family friend at the Institute. He brusquely told me not to be a fool: the right thing to do was to join the Indian Railway Service or Burmah Shell (the equivalents those days of a fat software job in today’s Bangalore). I went back dejected to my father with our friend’s advice, but he only asked me very simply, ‘So what do you want to do?’ I said I was bent on aeronautics. He just said, ‘Go ahead, then.’ So a matter that I had thought might have to be discussed over hours was settled in two minutes, and I ended up at the Indian Institute of Science—where I have stayed in some capacity or the other for most of the last fifty years. At the Institute one more world was opened for me by Professor Satish Dhawan, who represented on the campus an exciting breath of fresh air from the New World, for he came with a Ph.D. from the California Institute of Technology (Caltech), and was informal in manner and serious about work (just the opposite of most other faculty at the Institute at the time). Somewhat like the Spitfire, his laboratory was a seamless mix of science and technology. He had big compressors running the supersonic tunnels he had built, but (in those early years of the electronic age) many of the measurements in those tunnels were still made with lenses and galvanometers. He went on to become a great scientific leader in India, building a space research organization that grew to be a spectacularly successful technology development enterprise. But Dhawan combined his nationalist commitment to big science with a deep love for little science. I learnt from him how to do research even when one did not have all the equipment needed. His laboratory was full of beautiful little ‘gizmos’, as he called them, and we jointly added some more to the collection, including a simple but effective one- dollar box camera for fast recording of oscilloscope traces, some of which ended up in a paper in the Journal of Fluid Mechanics. At the end of two years Dhawan told me that to learn anything more I would have to go to Caltech. Strange as it may seem now, I was not at that time among those who were keen on going abroad; I was probably uneasy about doing the ‘fashionable’ thing, and my crazy circle of very intelligent friends in Bangalore had this extraordinary respect for those who stayed in India to do science—even if that meant not much science was done. Nevertheless I ended up at Caltech, and immediately realized that Dhawan was right to insist I go. I worked with Hans Liepmann, who had earlier been Dhawan’s own adviser there. It took me a year to get used to my transplantation, for in the 1950’s Bangalore and Pasadena were poles apart— geographically, scientifically, culturally and economically. But the following five years were some of the most intense in my life, because Liepmann and Caltech in their own friendly ways opened my eyes to one more world, that of international science done at the very frontiers of

the abdus salam international centre for theoretical physics 173 One Hundred Reasons to be a Scientist current knowledge. They generously accommodated an eccentric Asiatic, vegetarian fads and all, and later went so far as to make him feel Pasadena could be second home to him if not his first. At any rate I returned to Bangalore at the end of 1962, and apart from visits now and then to other parts of the world rediscovered my (first) home here. Over the forty years since then I have tried to keep a balance between building and doing, and would not trade it for anything else—although there have been moments of frustration every now and then. I soon became a confirmed fluid dynamicist, and was looking all the time for the most interesting research I could do in Bangalore with the facilities we had or could build ourselves. This was often a slow process, but it was sure, and in a few years’ time there was a group of outstanding students and assistants who quickly became experts at whatever they were doing, and it all became very exciting. Much of this research was concerned with what I now like to think of as flow transitions. It is a matter of common observation that a fluid flow can be laminar or turbulent—you can see that when you open a tap in your wash basin. For some reason the changes that take the flow from one state to the other began to fascinate me. Were those changes slam-bang, abrupt—as when the flow past a plate crumples into a turbulent spot—and if so how abrupt, and why? Or were they gradual—and if so when, and why? Can the flow go back from turbulent to laminar? This ‘reverse’ transition was a strange beast at the time, and I remember well-known fluid dynamicists who came to my laboratory in Bangalore in the 1960’s and 70’s and declared that they could not believe it—in spite of what I thought were the most elaborate measurements and the most convincing explanations that I and my students had fashioned by then. And I found shock waves—another kind of transition, this time from supersonic to subsonic flow—equally fascinating. And that kept me busy for many years. But in the 1970’s and 80’s I became convinced that the most interesting fluid-dynamical problem for an Indian scientist to tackle was the monsoons. So after many years of effort we succeeded in setting up a new Centre for Atmospheric (and now also Oceanic) Sciences at the Institute in 1982. A dynamic group of scientists at this Centre have gone on to do very interesting things on different aspects of the monsoons since then. I myself have had a long interest in clouds, often wondering why the type called cumulus (so often seen in Bangalore and elsewhere in the tropics) does not spread out like a rocket plume, but instead occurs in cauliflower-like heaps or rises high in ‘towers’. After several unsuccessful attempts we finally found an interesting way to study cloud-like plumes in (of all things) a water tank! This sounds surprising, but we could put heat into this ‘water cloud’ by passing electric currents (adding acid to the water to make it conducting), and so simulate the release of latent heat in the real cloud. (This, I thought, must be the special thing that makes a cloud different from an ordinary plume). And the experiments showed nicely why clouds look the way they do. (Unbelievable as it sounded at first, it seems as if this also has to do with a kind of ‘sub- transition’, involving loss of partial order—a rather soft transition this time, though). When I was watching clouds as a kid, a stern elder had (good-naturedly) rebuked me, ‘Hey! You sky- gazer! Better look at the ground too some time!’ But I continue to do sky-gazing, and love making those fake clouds in the laboratory as well. Looking back I think I have been fortunate in my teachers; they opened so many new doors for me and showed me fascinating new worlds. And I found that doing the unfashionable thing became addictive—and a lot of fun!

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