Proffessor Sir Roger Penrose OM FRS#
Roger Penrose has conducted outstanding research in pure mathematics and theoretical physics for more than 60 years. He is most widely acclaimed for his work on singularities, such as in black holes, which he proved can arise from the gravitational collapse of massive, dying stars. He has also made important contributions that explore possible connections between physics and consciousness, and set these out in best-selling books such as The Emperor's New Mind (1989).
Roger Penrose revolutionised the mathematical tools that we use to analyse the properties of spacetime. Previously, work on the curved geometry of general relativity had been confined to configurations with sufficiently high symmetry for Einstein's equations to be soluble explicitly, and by investigating small perturbations away from their symmetry. His more radical approach instead concentrated just on the topology of the space, or at most its conformal structure, since it is the latter — as determined by the lay of the lightcones — that determines the trajectories of lightlike geodesics, and hence their causal relationships. The importance of Penrose's epoch-making paper "Gravitational collapse and space-time singularities" was not only its result (roughly that if an object such as a dying star implodes beyond a certain point, then nothing can prevent the gravitational field getting so strong as to form some kind of singularity). It also showed a way to obtain similarly general conclusions in other contexts, notably that of the cosmological Big Bang, which he dealt with in collaboration with Stephen Hawking.
Roger invented twistor theory, a key tool in quantum theory. He proposed the cosmic censorship hypothesis — an idea of how the effects of the unpredictability of singularities are ‘hidden’ from us. Even his recreations have been creative: his discovery of a non-periodic form of tiling — Penrose tiling — has since been observed experimentally in quasicrystals.
In cosmology, he has proposed to replace conventional cosmology's initial inflationary phase by an entire previous universe aeon, whose exponentially expanding remote future conformally joins on to our own big bang. Recent analysis of the cosmic microwave background seems to give strong observational support to this unconventional idea.