IUCAA - Khagol # 129 - Oct 2022 - English

| KHAG L | No. 129 - OCTOBER 2022 | 05 Paddy :My friend It was a great shock when I heard that Paddy passed away. We had so much of shared history, in the early days, from the time we joined together for Phd at TIFR. Memories of time spent together in our youth, in movies, restaurants, discussing Physics and philosophy or being partners in a carrom tournament at TIFR. We went together to submit his PhD thesis to the Bombay University, simultaneously picking upmy guitar at VT station andwe joked that his thesis submission was being serenaded! Paddy was not only smart but also extra- ordinarily hard working. The legend was that he had worked through and solved the whole book on Gravitation by "Misner, Thorne and Wheeler", a 1000 page mammoth of a book, in his undergraduate days! This made his knowledge of GR unparalleled and a preoccupation with Gravity in all aspects a lifelong activity. It was this ability to work very hard and with a great self-discipline which enabled such a high level of productivity throughout his life. His clarity of thinking right from student dayswas such that he couldwrite a paper fromscratch almost overnight! He was to land in the UK one winter for his post doc and I was already there, and was Kandaswamy Subramanian to get him a winter coat. My mother was having heart surgery in Bombay and I received a telegram from Paddy, "Operation successful, meet me at airport". It was fortunate that the telegram did not fall into wrong hands! When he was at Cambridge, we made a pact that almost every weekend we would meet. His original idea was that he will only eat salad during that year, which I quickly dissuaded him from doing and so we cooked our crude versions of everything and survived while working on our first paper together. We also started learning all about structure formation together which finally resulted in a joint 150 page review few years later, on galaxy formation published in the Bulletin of the Astronomical society of India. We ended up writing several papers together on Structure formation. Author order was usually decided by tossing a coin. Then one of our papers submitted to Nature was rejected. We decided that we write a paper together only if it was of a quality deserving a Nobel prize, and of course, we never wrote another paper together! When joining IUCAA it was Paddy who first explained to me that it is important to interact with the University sector unlike when working in other institutes. Little did I then realize that later I was to end up with this being one of my prime duties! The one joint activity we did was to establish IUCAA pathways for reaching goals. It was delivered very powerfully and there was a stunned silence at the end of the talk. I believe the audience was fully convinced of the intellectual power in IUCAA, even though they had not quite understoodwhat had been said. I did not see much of Paddy in later years, since he mostly worked from home and came to the office only for short periods and for the occasional seminar or colloquium. He of course remained extremely active, speaking, teaching and working mostly on emergent gravity. During the pandemic I did not get to see him at all, and he passed away so suddenly before that cloud had lifted, at least partially. I miss him very much. But much of his passion lives in his daughter Hamsa, I greatly enjoy talking to her whenever I am able tomeet her. academic link with the JNU for the benefit of our Ph.D. students; often our wavelength would match perfectly to sort out teething issues. Paddy leaves behind a large legacy, of papers, books, reviews. My favorites are his masterful exposition on the vast range of Physics in Theoretical Astrophysics Volume I and his more recent book on Gravitation. He was excited in recent years about his work on emergent nature of gravity and it was clear, hewas on the verge of amajor breakthrough. Our most recent long chat was on a problem he was sorting out to do with dealing with random trajectories and taking derivatives. After our chat I sent him some sections from a book with Anvar Shukurov, where I had reworked related maths in context of magnetic fields transport and some related old papers. His response was typical; he said "Thanks! Meanwhile I am trying to do it all from first principles, reinventing several wheels! But as we both know that is sometimes the best route........". That was paddy. Although in recent years, we did not interact much, nor agree on many issues, sometimes vehemently, I was looking forward to years after both our retirement, where we would be able to get together as before. Farewell my friend.