Editorial: Ashoke Sen, string theory pioneer, does India proud

Indian theoretical physicist Ashoke Sen winning the prestigious Oskar Klein medal is a glorious testament to the country’s research achievements in quantum gravity and string theory. Awarded annually by Stockholm University and the Nobel Committee for Physics of the Royal Swedish Academy of Sciences, the medal commemorates the intellectual legacy of Swedish theoretical physicist Oskar Klein. Sen, a professor at the Bengaluru-based International Centre for Theoretical Sciences (ICTS), is the first Indian to receive the medal. It is an elite recognition for scientists who have made foundational contributions to theoretical physics. He is widely regarded as an architect of modern string theory, and his work has helped scientists understand the mysteries of black holes. Sen has previously received the Dirac Medal and the Breakthrough Prize in Fundamental Physics, both prestigious honours. String theory is one of the main efforts to bridge the inconsistencies between quantum theory and gravitation, in an attempt to find a new grand unified theory of physics that can explain the behaviour of all particles and forces at every scale, from tiny subatomic particles to large galaxies. In simple terms, string theory proposes that the fundamental building blocks of the universe are tiny, one-dimensional vibrating strings rather than point-like particles. Different vibration patterns of these strings produce particles with different properties, such as mass and charge. The main objective of string theory is to unite quantum mechanics with Einstein’s general theory of relativity. It aims to incorporate all four fundamental forces of nature — gravity, electromagnetism, strong force, and weak force— and all types of matter within a single framework.

Sen, who joins the ranks of past Oskar Klein Medal recipients such as Stephen Hawking, Peter Higgs and Kip Thorne, spent his life trying to make sense of the complex and chaotic universe and exploring the wild intersection of gravity, quantum mechanics and black holes. His work has reshaped string theory and given scientists fresh ways to understand black holes, fundamental forces, and the deep logic of nature itself. In 2012, Sen received the Breakthrough Prize in Fundamental Physics for work that contributed to the understanding that different string theories could represent different limits of a deeper, underlying theory. He was awarded the Padma Shri in 2001 and the Padma Bhushan in 2013 for his contributions to science. The Oskar Klein Medal is the latest in a series of top physics honours received by Indian scientists in recent years. Earlier this year, theoretical physicist Deepak Dhar was named a recipient of the Dirac Medal, making him the second Indian, after Sen, to receive the honour. A few years ago, Dhar was also awarded the Boltzmann Medal, another top prize in physics. He is the only Indian to win both the Dirac Medal and the Boltzmann Medal.