The universe began over 13 billion years ago with the Big Bang and is expanding. Surprisingly, the expansion rate is accelerating. This has been explained by the idea of dark energy - energy that is otherwise not detected except for its gravitational effects. Claims of a large under density or void in the matter distribution on scales out to 300 million parsecs have recently been made using samples of galaxies. These results could have profound implications for the Big Bang providing an alternative explanation for the acceleration of the universe without the need for dark energy. In this talk Professor Chris Collins will discuss the results of an alternative test of the matter distribution on these large scales using clusters of galaxies, which provide an independent and powerful probe of large-scale structure.