Early in his career, the University of Oxford mathematician Roger Penrose inspired the artist M. C. Escher to create Ascending and Descending, the visual illusion of a loop of staircase that seems to be eternally rising. It remains a fitting metaphor for Penrose's ever enquiring mind.

During his long career, he has collaborated with Stephen Hawking to uncover the secrets of the big bang, developed a quantum theory of consciousness with anaesthesiologist Stuart Hameroff and won the Nobel prize in physics for his prediction of regions where the gravitational field would be so intense that space-time itself would break down, the so-called singularity at the heart of a black hole.

Undeterred by the march of time - Penrose turned 91 this year - he is continuing to innovate, and even planning communications with future universes.

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