# Emeritus trio scoops the 2013 Dirac Medal

08 Aug 2013 James Dacey

The 2013 Dirac Medal has been awarded to three scientists whose wide-ranging work has brought profound advances in cosmology, astrophysics and fundamental physics. Thomas W B Kibble, Philip James E Peebles and Martin Rees all receive the honour, which is bestowed annually by the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy. The three scientists will also each receive a prize of $5000. ### Spontaneous symmetries Thomas Kibble, emeritus professor at Imperial College London, has made major contributions to our understanding of spontaneous symmetry breaking – the process at the heart of the Higgs mechanism. Indeed, in an interview last year with Physics World, Peter Higgs named Kibble as one of at least five other theorists who deserve credit for predicting the existence of the Higgs boson. Kibble also explored the importance of symmetry breaking in a cosmological context – investigating what happens when a symmetry “disappears” as the universe evolves from the Big Bang. “It is always very gratifying to have one’s work recognized by other physicists,” says Kibble. “This award is particularly special for me because of its association with my former colleague and inspiration, Abdus Salam, who founded the ICTP, and also because the other medallists this year are two astronomers for whose work I have the greatest respect – James Peebles and Martin Rees.” ### Across the universe Philip Peebles, a theoretical cosmologist who holds two emeritus-professor positions at Princeton University in the US, has worked on problems ranging from light-element synthesis to the nature of the dark universe. In the 1960s Peebles predicted some of the most important properties of the cosmic microwave background (CMB). He also quantified how galaxies cluster together to form large-scale structures over time and played a leading role in developing theories of “cold dark matter”. ### At the heart of darkness The third recipient, Martin Rees, is an emeritus professor at the University of Cambridge in the UK, where he has spent most of his research career. Like Peebles, Rees has also done pioneering work of the CMB and in 2005 the pair shared the$500,000 Crafoord Prize with James Gunn for their work on understanding the large-scale structure of the universe. Rees has a string of other achievements in astrophysics, including his work on the origin of quasars and the prediction that supermassive black holes lurk at the heart of galaxies.

In addition to his research achievements, Rees has also been instrumental in science policy and the democratization of scientific ideas, having authored several popular-science books. In 2011 Rees was awarded the £1m Templeton Prize for his “profound insights” into the nature of the cosmos that have “provoked vital questions that address mankind’s deepest hopes and fears”. He was also president of the Royal Society between 2005 and 2010, during which time he spoke to Physics World in this video interview about space, politics and scientific advice.

All three scientists received the prize today. Since 1985, the prize has been awarded annually on 8 August – the day on which the British Nobel-prize-winning theorist Paul Dirac was born in 1902. Dirac was a close friend of the ICTP, which was founded in 1964 by the Nobel laureate Abdus Salam as an international research centre to promote scientific excellence in the developing world.