Sue Lawley's castaway this week is the mathematician Sir Roger Penrose. His prize-winning work with Stephen Hawking on the nature of black holes brought his name to public attention in the 1960s. Since then he has made a controversial contribution to the debate over human consciousness and whether or not computers will ever be able to mimic the workings of the human mind.

[Taken from the original programme material for this archive edition of Desert Island Discs]

Favourite track: Crucifixion from B Minor by Johann Sebastian Bach