21st International Symposium on Very High Energy Cosmic Ray Interactions - ISVHECRI 2022 (Virtual)

On behalf of the International Advisory Committee (IAC), it is my privilege and honour to extend a warm welcome to the participants of the 21st International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI-2022). This symposium is being organised at the Tata Institute of Fundamental Research (TIFR) Mumbai after the original plan to host it in April 2020 at Ooty had to be postponed due to the Covid-19 pandemic. This multi-disciplinary symposium spans three areas of research which include cosmic ray physics, nuclear physics and high-energy physics the areas that TIFR also engages in. In this context, it is satisfying to learn that TIFR would accord greater autonomy to the Cosmic Ray Laboratory (CRL) in Ooty by transforming it into a National Cosmic Ray Centre. This should significantly enhance the physics impact of its flagship GRAPES-3 experiment. The GRAPES-3 is a growing collaboration of Indian and Japanese groups which in addition to the development and large-scale production of particle detectors has also made important contributions in the emerging areas of space weather and atmospheric sciences. Another landmark event occurred on 31 March 2022, when Prof. T. Kajita, Director of the Institute for Cosmic Ray Research in Japan and Prof. S. Ramakrishnan, Director, TIFR signed a Memorandum of Cooperation to further enhance scientific exchange and cooperation between Japan and India in the areas of cosmic rays and astroparticle physics.

 

TIFR has a tradition of inviting eminent scientists to serve as Honorary Fellows, and from time-to-time to seek their counsel on the areas and direction of research to be pursued. It is a source of great pleasure that two of the Honorary Fellows, namely, Prof. T. Kajita and Prof. S.C.C. Ting are delivering invited talks during ISVHECRI-2022. I once again extend a warm welcome to all of the participants who are physically present as well as those joining remotely.

 

Unfortunately, 20 February 2022 witnessed the passing away of one of the pioneers of our field, a dear friend and colleague Professor Thomas Korff Gaisser, Martin Pomerantz Professor Emeritus of Physics at the University of Delaware, USA. I have so many wonderful memories of interactions with Tom, spanning the past 34 years that I can not help but share at least some of them with the participants of this symposium. I first met Tom in 1988 at ICTP in Trieste, Italy when I attended a summer school where he lectured. I used to ask a lot of questions to improve my understanding of the subject. Sometimes, he would reply that “let me think it over and I would discuss it tomorrow”. A few days before he left, Tom asked if I would spend a few months with his group in the USA. Due to several constraints I had to decline his generous offer. In hindsight, I can safely state that that was certainly not a smart decision as the people who worked with him all became leaders in our field! Of course, the ever gracious Tom remained a warm and trusted friend.

 

Tom served our community for 12 long years through the IUPAP by being a member, Secretary, Vice-Chair and the Chair of Commission C4 on Cosmic Rays (now Astroparticle Physics). He was recognized by his peers for his outstanding scientific contribution with the award of the O’Ceallaigh medal and finally during the 34th ICRC in Busan, South Koreal by the Homi Bhabha medal and prize. A condition for this award is that the winner is invited to visit the TIFR, Mumbai and CRL, Ooty to deliver a public lecture at each venue. Tom’s lectures were massively popular attracting 1000 and 600 participants in Mumbai and Ooty, respectively. Major Indian national newspapers (circulation in millions) interviewed him and prominently reported.

 

His monograph on Cosmic Rays is a masterpiece and remains an indispensable tool in the armoury of every aspiring and seasoned cosmic ray physicist. He along with late Prof Martin Pomerantz was the prime mover behind the creation of the Shakti P. Duggal prize in 1983 to recognize young scientists which became the first international award in our field. I had highly rewarding and memorable interactions with Tom especially during my work as the Chair, C4. He selflessly served as a member of the International Scientific Program Committee (SPC) for the past several ICRCs. He had absolutely no qualms about working in the committees chaired by people far less experienced and/or accomplished than him. He was among the founding members of ISVHECRI series of symposia where he was a constant presence. As a member of the IAC, he handsomely contributed to the present edition as well. Sadly his untimely passing has robbed us of his future counsel, a view shared by the members of IAC and SPC. The inaugural session of this symposium provided the perfect venue to pay respects to this great yet humble physicist, teacher, mentor and colleague. Several of Tom’s colleagues including Ralph Engel, Takaaki Kajita, Paolo Lipari, Subir Sarkar, Alan Watson, and several others shared their recollections of this outstanding colleague. It was especially poignant that Tom’s wife and one of his collaborator Julia Gaisser joined online. Tom Gaisser will not be forgotten.