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.

Meet a fascinating thought experiment close to the speed of light.

The impact of GPS on our lives is celebrated with the Queen Elizabeth Prize for Engineering.

Leslie Lamport explains how he used logical clocks to set history straight in distributed systems.

Leslie Lamport explains how an understanding of special relativity helped him realise how to order events in computer science, and enabled the development of distributed computing.

Our digital lives rely on distributed computer systems, such as the internet, but understanding the order of events in such systems is not always straightforward.

Read about the rocky road to one of Einstein's greatest achievements: the general theory of relativity, which celebrates its centenary this year.

How to catch those elusive gravitational waves.

Physicists at the University of California, Los Angeles set out to design a better transistor and ended up with a discovery that may lead to a new explanation of electron spin and possibly even the nature of space.

And what are gravitational waves?

Sonia Buckley travels through higher dimensions