William Paul Thurston (1946-2012), US mathematician. Thurston received his doctorate in 1972 from the University of California, Berkeley. His work on 3-manifolds pioneered low-dimensional topology. Several theorems and conjectures are named for him, and he later worked on hyperbolic 3-manifolds. He worked at a number of institutions, including Cornell University and Princeton University. His awards included the Fields Medal (1982). Elected to the National Academy of Sciences (1983), he was director of the Mathematical Sciences Research Institute from 1992 to 1997. Photographed in June 2010.