Geraint F. Lewis is a Professor of Astrophysics at the Sydney Institute for Astronomy, part of the School of Physics at the University of Sydney. Originally from Old South Wales, Geraint undertook degrees at the University of London and Cambridge, before postdoctoral positions in the USA and Canada. He joined the Anglo-Australian Telescope in 2000, before moving to the University of Sydney in 2002. His research focuses upon the dark side of the universe, with theoretical, observational and computational studies of the dark matter and dark energy which dominate the evolution of the cosmos.