Physics professors

This is Professor Jim Al-Khalili introducing world-renowned physicist Professor Sir Roger Penrose, guest speaker at the inaugural Lewis Elton Lecture at the University of Surrey on the 16 February 2012.

Profs Jim Al-Khalili and Sir Roger Penrose

A Penrose space-time diagram on the overhead projector during the lecture

Abstract: 

According to currently standard cosmology, the universe started with a Big Bang, immediately followed by a fleeting moment of exponential expansion, called “inflation”. Following this it settled down to a more sedate expansion, but due to what is called “dark energy," it is currently commencing a second period of exponential expansion that is expected to continue indefinitely. In this talk I describe an alternative idea, which argues that this picture provides merely one aeon of a continual succession of such aeons. The Universe never collapses in this model, but the remote future of each aeon becomes, when infinitely scaled down, the big bang of the next. Collisions between supermassive black holes in the aeon previous to ours would, according to my model, provide disturbances that should be just about observable in the cosmic microwave background of our own aeon. In this talk I shall describe evidence indicating that these disturbances may actually be present, and possibly providing us with some hint of what the aeon prior to ours may actually have been like. The talk will be largely free of equations, depending mostly on pictures, but a brief summary of the equations needed for the theory will be provided at the end.