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 Cambridge, spoke to Sky News to explain how the theory works and why it’s important.

“I don’t think it’s an exaggeration to say that Einstein’s general theory of relativity completely revolutionised our understanding of the universe. Nothing about modern cosmology can be understood without the context of Einstein’s theories,” Dr Bothwell added.

Thanks to the experiment 100 years ago today, space itself was no longer thought of as the geometric plane suggested by classical mechanics as formulated by Sir Isaac Newton, thought of like a table necessary to roll a ball over.

Instead, according to Einstein’s theory, space and time were the same thing – a single construct which could be called spacetime.