Sir Thomas Walter Bannerman Kibble (; 23 December 1932 – 2 June 2016) was a British theoretical physicist, senior research investigator at the Blackett Laboratory and Emeritus Professor of Theoretical Physics at Imperial College London. His research interests were in quantum field theory, especially the interface between high-energy particle physics and cosmology. He is best known as one of the first to describe the Higgs mechanism, and for his research on topological defects. From the 1950s he was concerned about the nuclear arms race and from 1970 took leading roles in promoting the social responsibility of the scientist. Early life and education Kibble was born in Madras, in the Madras Presidency of British India, on 23 December 1932. He was the son of the statistician Walter F. Kibble, and the grandson of William Bannerman, an officer in the Indian Medical Service, and the author Helen Bannerman. His father was a mathematics professor at Madras Christian College, and Kibble grew up playing on the grounds of the college and solving mathematics puzzles his father gave him. He was educated at Doveton Corrie School in Madras and then in Edinburgh, Scotland, at Melville College and at the University of Edinburgh. He graduated from the University of Edinburgh with a BSc in 1955, MA in 1956 and a PhD in 1958. Career Kibble worked on mechanisms of symmetry breaking, phase transitions and the topological defects (monopoles, cosmic strings or domain walls) that can be formed. He is most noted for his co-discovery of the Higgs mechanism and Higgs boson with Gerald Guralnik and C. R. Hagen. As part of Physical Review Letters 50th anniversary celebration, the journal recognised this discovery as one of the milestone papers in PRL history. He was awarded the American Physical Society's 2010 J. J. Sakurai Prize for Theoretical Particle Physics. While Guralnik, Hagen, and Kibble are widely considered to have authored the most complete of the early papers on the Higgs theory, they were controversially not included in the 2013 Nobel Prize in Physics. In 2014, Nobel Laureate Peter Higgs expressed disappointment that Kibble had not been chosen to share the Nobel Prize with François Englert and himself. Kibble pioneered the study of topological defect generation in the early universe. The paradigmatic mechanism of defect formation across a second-order phase transition is known as the Kibble-Zurek mechanism. His paper on cosmic strings introduced the phenomenon into modern cosmology.