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.

Come on a fantastic journey from some of our oldest ideas about physics to the biggest mystery of the modern age!

Over the last few decades physicists have been developing a curious idea. Perhaps the world we inhabit is a hologram, lacking a crucial feature of the world as we perceive it: the third dimension.

We discuss new and fascinating observations of gravitational waves with three of our favourite cosmologists.

We may be a little closer to a direct detection of dark energy thanks to a new result that came about, in a sense, by accident.

Could there be more than three?

A possible way of resolving the greatest problem of physics.

Explore the biggest problem in modern physics.

As we are well over half way through advent, we thought today we'd look towards the future of the Universe

On the ninth day of advent we find out about the maths of black holes.

Behind door #8 we answer all the questions you've ever wanted to ask about the physical reality of black holes!