Thanu Padmanabhan

Thanu Padmanabhan was a distinguished professor at the Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune, India. He was one of the leading experts in the fields of general relativity, cosmology and quantum gravity. He made significant contributions to the understanding of dark energy, the origin of cosmic structures, and the emergence of gravity from thermodynamics. He also wrote several popular books and articles on physics and astronomy, aimed at both students and general public. Padmanabhan was born on 10 March 1957 in Thiruvananthapuram, Kerala, India. His father, Thanu Iyer, was a mathematician who worked in the forest department, and his mother, Lakshmi Iyer, was a homemaker. He had a passion for mathematics and geometry from an early age, and published his first research paper on general relativity when he was still a B.Sc. student at the age of 20. He completed his B.Sc. and M.Sc. in physics from the University College Thiruvananthapuram, part of Kerala University, winning gold medals in both. He then joined the Tata Institute of Fundamental Research (TIFR) in Mumbai for his Ph.D., which he completed in 1983 under the supervision of Jayant Narlikar. He became a faculty member at TIFR in 1980 and held various positions there until 1992. He also spent a year at the Institute of Astronomy, Cambridge, as a visiting scientist in 1986-87. In 1992, he moved to Pune to join the IUCAA as a senior professor. He served as the Dean of Core Academic Programmes from 1997 to 2015, and became a distinguished professor in 2016. He was also an adjunct faculty at several other institutions, such as TIFR, Harish-Chandra Research Institute, Raman Research Institute, Indian Institute of Science Education and Research (IISER) Pune and IISER Mohali. He was actively involved in teaching and mentoring students and postdoctoral fellows at IUCAA and other places. He supervised nearly 30 Ph.D. students and published nearly 300 papers and reviews in international journals. Padmanabhan's research covered a wide range of topics in theoretical physics and cosmology, such as gravitational lensing, cosmic microwave background radiation, large-scale structure formation, dark matter, dark energy, inflation, quantum cosmology, black holes, holography and emergent gravity. He developed several original ideas and models to explain various phenomena in the universe, such as the Padmanabhan-Narlikar theory of gravity , the structure formation scenario based on lognormal distribution , the holographic equipartition principle , the emergent perspective on gravity , and the thermodynamic interpretation of gravity . He also proposed several observational tests to distinguish between different models of dark energy and quantum gravity . Padmanabhan was also a prolific writer and communicator of science. He wrote ten books on physics and cosmology, including six graduate-level textbooks published by Cambridge University Press . His books covered topics such as structure formation in the universe , gravitation [^10^], quantum field theory ¹¹, thermodynamics ¹², quantum mechanics ¹³ and cosmology ¹⁴. His books were widely used by students and researchers around the world and received high praise from experts. He also wrote several popular books and articles on science for general audiences, such as After the First Three Minutes ¹⁵, Sleeping Beauties in Theoretical Physics ¹⁶, and The Story of Physics ¹⁷. He was a regular contributor to the Resonance journal of science education ¹⁸ and the Science Age magazine . He gave numerous public lectures and interviews on various aspects of physics and cosmology, and participated in several outreach activities to promote science awareness and education. Padmanabhan received several national and international awards and honors for his scientific achievements and contributions. Some of them are: - Kerala Shastra Puraskaram, 2021 - M. P. Birla Memorial Award, 2019 - Homi Bhabha Lecturer at UK (IoP-IPA award), 2014 - TWAS Prize in Physics, 2011 - Infosys Science Foundation Prize for Physical Sciences, 2009 - J. C. Bose National Fellowship, 2008 - INSA Vainu Bappu Gold Medal, 2007 - Padma Shri, the fourth highest civilian award of India, 2007 - Al-Khwarizmi International Award, 2005 - Miegunah Fellowship from the University of Melbourne, 2003 - Millennium Medal of the CSIR, India, 2000 - Shanti Swarup Bhatnagar Award for Physical Sciences, 1996 Padmanabhan was also a fellow of several prestigious academies and societies, such as: - The World Academy of Sciences (TWAS) - Indian National Science Academy (INSA) - Indian Academy of Sciences (IASc) - National Academy of Sciences, India (NASI) - Indian Physics Association (IPA) Padmanabhan was married to Vasanthi Padmanabhan, who has a Ph.D. in astrophysics from TIFR, Mumbai. She is now a professor and dean at B.S.Abdur Rahman Institute, Chennai. They have one daughter, Hamsa Padmanabhan, who also has a Ph.D. in astrophysics from IUCAA, Pune. She is currently a postdoctoral researcher at the University of Geneva, Switzerland. Padmanabhan died on 17 September 2021 at the age of 64 after a heart attack at his residence in Pune. His sudden demise has shocked and saddened his family, friends, colleagues and students. He will be remembered as a brilliant scientist, a passionate teacher, a prolific writer and a humble human being.