Today marks the centenary of an experiment which proved Albert Einstein's theory of general relativity - but what exactly is that theory? Dr Matthew Bothwell, an astronomer at the University of ...

The accelerating expansion of the universe could be explained by modifying general relativity so that gravity has mass – or so thinks a small group of physicists. Matthew Francis reports What lies ...

It was the discovery that changed the universe - or rather our understanding of the universe. One hundred years ago today, Albert Einstein presented his theory of general relativity. So for the next ...