The SKA will look deeper into the Universe and further back in time than any other telescope before it. I hold a SKA Research Chair, and my research aims to use the power of the SKA pathfinders and the SKA to map the distribution of galaxies in the Universe. With these maps, we will be able to find out more about one of the biggest puzzles in modern physics – what is the nature of the Dark Energy that is forcing the Universe to expand faster and faster? Our model of the Universe is based on Einstein’s 1915 theory of General Relativity. This theory has been very successful in unlocking the secrets of the vast and ancient Universe. But perhaps Dark Energy does not exist – and instead, the acceleration of the Universe signals a breakdown of Einstein’s theory on very large scales? The SKA will give us the accuracy to test this possibility.