Roger Penrose (born 1931), British mathematician, with the Penrose tiling system named after him. Penrose, renowned for his work in mathematical physics, studied this tiling system in the 1970s. Using only two tiles of a particular shape, complex, non-repeating patterns can be generated. Penrose has also worked on black holes, cosmology, quantum mechanics and human consciousness. His awards include the Eddington Medal, the Royal Medal, the Wolf Prize, and the Albert Einstein Medal. Penrose was knighted in 1994. Photographed in 1989 – CORBIN O’GRADY/SCIENCE PHOTO LIBRARY