Govind Swarup Innovator, Mentor & Motivator (23 March 1929 - 07 September 2020)

Obituary Govind Swarup Innovator, Mentor & Motivator (23 March 1929 - 07 September 2020)

Somak Raychaudhury

After independence, K.S. Krishnan moved to Delhi as the founding Director of the CSIR-National Physical Laboratory. In 1950, having finished his MSc, Swarup joined him there. Krishnan was at that time interested in the quantum theory of magnetism. Only a few years before, Yevgeny Zavoisky had been awarded the Nobel prize for the discovery of electron paramagnetic resonance. Krishnan set Swarup the task of measuring the spin resonance in materials at microwave frequencies. Swarup set about making the equipment from scratch, in less than two years, from radar parts left over from the Second World War to make measurements at a wavelength of 3 cm. This was the first sign of the innovativeness that became so much the “Swarup brand” throughout his entire life. If Indians are known for “jugaad”, Govind Swarup was its embodiment. At the URSI General Assembly in Sydney in 1952, Krishnan met some of the pioneering radioastronomers who were also modifying advanced radar equipment to build antennae to study the Universe. Greatly inspired by his talks upon his return, Swarup ventured to Australia to work at Potts Hill in Australia with Joseph Pawsey, building an array of 2 m dishes to receive signals at 500 MHz. After his return to India, Swarup set off to the USA to learn more, first at the Fort Davis station of the Harvard Observatory in Texas, where he NE of the pioneers of science research and education built equipment to detect a radio burst from the Sun, and then in India, Govind Swarup passed away in Pune on at Stanford University in California, where he worked on his O7 September 2020. doctoral thesis with the famous R.N. Bracewell. Today India is one of the world’s leading communities in After his PhD, Swarup joined the Stanford faculty, but studying the Universe at radio wavelengths, and it is largely in his heart he wanted to return to India, where the country’s because of Govind Swarup’s groundbreaking achievements. post-independence infrastructure for science and technology This he achieved by conceiving and constructing some of the was just being set up. He was one of four Indian radiophysicists most innovative telescopes and instruments ever built for the working in top laboratories in the USA, who wrote to purpose, and by inspiring generations of young engineers and research Institutions in India about their plans to join in this physicists, whom he taught not only to dream of impossible effort. Fortunately, a positive response from Homi Bhabha things, but also how to achieve them. led Swarup to join the Tata Institute of Fundamental Research Govind Swarup grew up in a small town in Uttar (TIFR) in Bombay, and establish a unique radioastronomy Pradesh, and when he went to study at Allahabad University group there. in 1945, it had one of the best Physics departments in the Under the leadership of Swarup, the TIFR group first set country, built from scratch over a decade by Meghnad Saha. up a solar array with the 32 antennae that he had worked on Even though Saha had left by then, many of his students and in Australia, and had since been shipped to India. This was colleagues taught and mentored the bright crop of students the at Kalyan, near Bombay, following which Swarup, and his department continued to attract. Half a century later, talking increasingly confident group of students and engineers, found to us, Swarup often fondly remembered his teachers – B.N. a slope of a hill near Ooty that exactly matched the latitude Srivastava, who wrote the seminal textbook on Heat, along of the place. Here they built the first unique giant telescope with Saha, that is still used in Colleges all over the country; of Swarup’s design – made of fine wire mesh on a monolithic K.S. Krishnan, who had worked with C.V. Raman in Calcutta parabolic cylindrical frame, half a kilometre long and 30 m on the discovery of the Raman Effect, and many others. wide. This was built ingeniously on this natural Equatorial

34 | Science Reporter | October 2020 The Giant Metrewave Radio Telescope (GMRT) – established under the Prof. Govind Swarup (extreme left) with Professor Jayant Narlikar while leadership of Prof. Govind Swarup for radio astronomical research at naming a road after Vainu Bappu metre wavelengths (Source: http://www.gmrt.ncra.tifr.res.in/)

mount, such that tracking celestial sources would be largely Govind Swarup won many accolades in his life – the done by the rotation of the Earth, with a motor drive required Shanti Swarup Bhatnagar award, the Padma Shri, the Grote for just one axis. Swarup also chose 327 MHz as the operating Reber award and the Fellowship of the Royal Society, to name frequency, in the range of radio-frequencies that hadn’t been a few. But his greatest reward seemed to be in mentoring well studied before. generations of peers and younger students, and he was very The Ooty Radio Telescope (ORT), which started to generous with his time and ideas. operate in 1969, made many pathbreaking measurements I first met him as an undergraduate, visiting the Ooty and discoveries, including that of new pulsars, quasars and telescope on my scholarship tour. His unbridled enthusiasm gravitational lenses, and is still operational. Some of the was so infectious that half of the group, at the end of the day, measurements of the counts of radio sources made by Kapahi wanted to be an astronomer like him! I cannot recall a single and Swarup, made with the ORT, went on to provide strong conversation with him in which he hadn’t been excited about support for the Big Bang theory of Cosmology. new things, managing to infect everybody around him with The ORT did not just put India on the world map of his enthusiasm. Astronomy, it also produced a confident and ingenious bunch The frugality of Swarup’s approach was outstanding – he of young engineers and scientists, which, inspired by this and his group came up with innovative ideas to build things visionary, was ready to take up any challenge. They moved at a fraction of the usual cost, making it possible to make to Pune to set up to build the world’s largest radio-telescope these world-beating facilities with the small budgets typical array at low radio-frequencies – thirty 45-m light-weight wire- of our institutions. Equally remarkable was the way his mind mesh dishes, spread over 30 km of vineyard territory along worked – he could in an instant work out complicated physical the Pune-Nashik highway. They operated at frequencies as models in his head in a very own intuitive approach. Rajaram low as 150 MHz, aimed at finding the spin-flip transition of Nityananda gives an example: “…I remember a serious debate hydrogen, ordinarily at 1420 MHz in the lab, but redshifted on the force that wind exerts on a cylinder – my number to much lower frequencies, at distances as far away as 90% to was 20% higher than his, which meant a design for a radio the edge of the Universe, to detect diffuse hydrogen before it telescope he was proposing had to be heavier to withstand collapsed to form galaxies. wind forces. We even went to an institute of wind engineering The Giant-Metrewave Radio Telescope (GMRT) is now in Chennai. He was right, of course.” one of the top astronomical facilities of the world for two Till his last day, everybody around him felt that breathless decades, studying all sorts of sources from planets, stars to excitement with which he could infuse all who interacted with radiogalaxies and supermassive black holes. Observers from him. A hundred years from now, he will be remembered as all over the world compete for time on this facility, which the Man who came up with all the ideas, and knew how to is over-subscribed three times over. As a Professor at the turn these visions into the very tangible legacies he has left University of Birmingham in the UK, my students and I used for us. to come several times a year to Pune to observe with the GMRT, and upon my return to India, I still use this unique instrument, which has now been upgraded, in which Swarup Dr Somak Raychaudhury is Director, IUCAA (Inter- continued to play a role. The GMRT is now a pathfinder University Centre for Astronomy and Astrophysics), Pune, observatory for the Square Kilometer Array – the Next Big Ganeshkhind, Post Bag 4, Puné-411007. Thing in Radioastronomy. Email: [email protected]

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