Professor Tamara Davis uses astrophysics to test our fundamental laws of physics, and study the nature of dark energy and dark matter. She is one of the most highly cited astrophysicists in the world. Her contributions include testing advanced theories of gravity, measuring time-dilation of distant supernovae, using galaxies to measure the mass of the lightest massive particle in nature (the neutrino) and discovering that active galaxies fuelled by black holes can be used as standard candles.