Roddam Narasimha was in rarefied company as a scientist-engineer. But, if you consider his exceptional research output along with his track record in public service, he is perhaps second to none. RN, as he was lovingly referred to, passed away in Bangalore on December 14. The scientific community has lost a transcendent member, and India, a model citizen. Narasimha left behind a towering legacy.

At the start of his research career, Narasimha worked on problems concerning turbulence, a feature of fluid flows that has vexed scientists for more than a century. Flow in a pipe at low enough speeds is well-behaved, regular, and predictable – a laminar state. But if you ramp up the speed, the flow transitions to an irregular mess – a turbulent state. Narasimha uncovered details of how certain flows make this transition and what the properties of the turbulent state are.

For his PhD at Caltech, which he finished in 1961, Narasimha developed analytical tools to understand the dynamics of extremely dilute gases (rarefied), the kind that populates the upper atmosphere or regions around space vehicles. These topics became a launchpad for his future research endeavors.

In the early 1960s, he returned to India, set up shop at the Indian Institute of Science, and revisited the subject of laminar-turbulent transition. He made state-of-art measurements of relaminarisation –
a unique scenario where flow transitions from turbulent to laminar.

Narasimha group made several key contributions in the fluid mechanics of turbulence and the gas dynamics of shock waves. His expertise in these subjects made him an ideal and important role-player in India’s burgeoning space and aeronautics programme in the early 1970s.

Developing Tejas

One of Narasimha’s more publicised contributions is his role in the development of Tejas, a home-made Light Combat Aircraft that ushered in significant advancement in allied fields like materials engineering and Computational fluid dynamics.

He also vigorously pushed to establish research in atmospheric fluid dynamics. His goal was to probe a monstrously difficult system: the Indian monsoon.

Over the years, Narasimha and his collaborators borrowed tools from statistical data analysis, mathematics, and fluid mechanics to study the Indian monsoons with impressive scientific rigor. A prime example of this is a decades-long pet project of creating clouds in the lab to better understand them. This has culminated in an experimental set-up that now takes up a corner of a lab in Bangalore’s Jawaharlal Nehru Centre for Advanced Scientific Research.

The “cloud chamber’’ is so awe-inspiring that it should be put on a brochure to advertise science’s coolness quotient.


Administrative stints

Narasimha balanced first-class research with several administrative stints, where he no doubt doubled as a tour-de-force engineer. He was the director of the National Aerospace Laboratories for almost a decade. He also served as the director of the National Institute of Advanced Study for seven years. During this time, he was a vocal supporter of India’s nuclear policy in the aftermath of Pokhran 2. In 2004, after retiring from the National Institute of Advanced Study, Narasimha took up a position at JNCASR and continued doing research will the very end.

Even though I hardly ever interacted directly with him, he was such a polymath that even second-hand interactions were influential in their ways. He was often seen in the campus canteen with his research group, no doubt sharing insights from the bag of infinite knowledge at his disposal. Narasimha took a keen interest in such a myriad of subjects that it would be nigh impossible to summarise them here.

He wrote eloquently on topics at the intersection of science, policy, and culture. Throughout his career, Narasimha was an astute student of science, philosophy, history, and the philosophy and the history of science.

Narasimha guided several generations of scientists. Many of his students are now incredible researchers in their own right. Nature gave him a Lifetime Achievement Award last year as part of its Mentoring in Science awards. While the recognition underscores the exceptional nature of his mentorship, it belies the sheer volume of scientists contained in Narasimha’s academic footprint. You would be hard-pressed to find a department in India that carries out research in fluid mechanics or aerospace engineering and has remained untouched by the spread of his academic genealogy.

My encounter with RN

I have only spoken to Narasimha once. I had been commissioned to write a piece on unsolved problems in science and wanted a quote on the treacherous nature of turbulence from him. While I was in his office, he got a phone call and excused himself. This happened a couple of times. Narasimha apologised and promised I wouldn’t leave without a quote. And then, in one fell swoop, he uttered a paragraph that was perfectly concise and cogent. It was as if he had been constructing it in his head all along.

Roddam Narasimha remained eminently approachable and humble despite his elevated stature, somewhat of a rarity in Indian science. There are a lot of things young scientists can learn from how Narasimha conducted himself. I looked up to his endless thirst for knowledge and deeply admired his ability to be a renaissance man.

I’ve reached the end of this piece without mentioning that Narasimha was a recipient of the Padma Vibhushan, India’s second-highest civilian honor. It completely slipped my mind, until now. But, somehow, I think if RN were reading this, he wouldn’t mind.

Ronak Gupta is a graduate student at the University of British Columbia. He did a masters in fluid mechanics from the Jawaharlal Nehru Centre for Advanced Scientific Research.