Air Date: 03/05/2008
Air Time: 7:00 PM EST
Length: 1 Hours, 18 Minutes, 41 Seconds
The evidence that the universe emerged 14 billion years ago from an event called 'the big bang' is overwhelming. Yet the cause of this event remains deeply mysterious. In the conventional picture, the 'initial singularity' is unexplained. It is simply assumed that the universe somehow sprang into existence full of 'inflationary' energy, blowing up the universe into the large, smooth state we observe today. While this picture is in excellent agreement with current observations, it is both contrived and incomplete, leading us to suspect that it is not the final word. In this lecture, the standard inflationary picture will be contrasted with a new view of the initial singularity suggested by string and M-theory, in which the bang is a far more normal, albeit violent, event which occurred in a pre-existing universe. According to the new picture, a cyclical model of the universe becomes feasible in which one bang is followed by another, in a potentially endless series of cosmic cycles. The presentation will also review exciting recent theoretical developments and forthcoming observational tests which could distinguish between the rival inflationary and cyclical hypotheses.
Neil Turok currently holds the Chair of Mathematical Physics at Cambridge University, prior to which he was Professor of Physics at Princeton University. In 1992 he was awarded the James Clerk Maxwell medal of the UK Institute of Physics.
Turok has worked in a number of areas of mathematical and early-universe theory, focusing on observational tests of fundamental physics in cosmology. In the early 1990s, his group showed how the polarization and temperature anisotropies of the cosmic background radiation would be correlated, a prediction which has been confirmed in detail by recent precision measurements. The team also developed a key test for the presence of the cosmological constant, also recently confirmed.
With Stephen Hawking, he later developed the Hawking-Turok instanton solutions describing the birth of inflationary universes. Most recently, with Paul Steinhardt at Princeton, he has been developing a cyclic model for cosmology, according to which the big bang is explained as a collision between two "brane-worlds" in M-theory. In 2006, Steinhardt and Turok showed how the model could naturally incorporate a mechanism for relaxing the cosmological constant to very small values, consistent with current observations. Steinhardt and Turok cowrote the recent popular science book "Endless Universe."
In 2003, Turok, who was born in South Africa, founded the African Institute for Mathematical Sciences (AIMS) in Cape Town, a postgraduate educational center supporting the development of mathematics and science across the African continent. In 2007, he was appointed Director of the Centre for Theoretical Cosmology (CTC) in Cambridge.
Turok has been recently awarded a TED prize (http://www.ted.com/) for his contributions to theoretical cosmology, and for his work in Africa.