Stephen William Hawking, CH, CBE, FRS (born 8 January 1942) is a theoretical physicist. Hawking is the Lucasian Professor of Mathematics at the University of Cambridge, and a Fellow of Gonville and Caius College, Cambridge. He is known for his contributions to the fields of cosmology and quantum gravity, especially in the context of black holes, and his popular works in which he discusses his own theories and cosmology in general. These include the runaway popular science bestseller A Brief History of Time, which stayed on the London Sunday Times bestseller list for a record-breaking 237 weeks.