general relativity

Everyone knows what time is. We can practically feel it ticking away, marching on in the same direction with horrifying regularity. Time has enslaved the Western world and become our most precious commodity. Turn it over to the physicists however, and it begins to morph, twist and even crumble away. So what is time exactly?

This podcast featuring Paul Davies, a theoretical physicist and cosmologist at Arizona State University and Director of BEYOND: Centre for Fundamental Concepts in Science, explores this difficult question and accompanies our What is time article.

Find out about the heroic effort that led to the detection of gravitational waves and the excitement of their discovery.

A quick introduction to one of the greatest discoveries of the century.

A quick introduction to the monsters that lurk at the centre of each galaxy.

David Tong explains one of the most important equations in science.

The newly observed ripple in spacetime will help us unlock some of the secrets of the Universe.

Time and space form the stage on which events unfold. But what if the stage itself becomes part of the action? We take a brief tour through the history of space and time and see how ideas have changed since the time of Isaac Newton.

Has the future already already been written? Is time just an illusion? Take a step outside of spacetime with cosmologist Marina Cortês to discover the block universe.

Fundamental physics says time is symmetric - so why does time move forwards for us in a block universe?