Roger Penrose is a mathematician best known for his popular books on physics and the mind, and for his fundamental work in general relativity theory, while his fascination with geometry has led to some curious but important discoveries.
Like Stephen Hawking, Penrose has contributed a great deal to the understanding of black holes. His discovery in 1964 that a collapsing star must, after a certain point, continue its collapse to infinite density (irrespective of symmetry assumptions) showed that black holes are a clear implication of Einstein's general relativity. His cosmic censorship hypothesis of 1969 suggested that such infinite density regions are always hidden from an outside observer.
Penrose has developed twistor geometry, a system which places the two fundamental theories of twentieth-century physics on the same mathematical basis and thereby provides a new language for a description of the universe. He has also proposed a scheme whereby the limits of quantum theory may be experimentally probed.
Professor Penrose has frequently applied his imagination to inventing unusual geometrical figures. Most importantly, he discovered the intriguing Penrose tiles whose unexpected properties are still being investigated.