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.

What is time? What is space? Are there parallel universes? Join Plus and FQXi on a journey exploring these and many more questions on the frontiers of physics. What do you think is science fiction and what do you think we close to proving are science facts? Find out more about scientific developments in these areas, ask your own questions and debate the answers!

More than you think! In this episode of our podcast we talk to theoretical physicist David Berman to find out more...

Is the Universe finite or infinite? Is there infinity inside a black hole? Is space infinitely divisible or is there a shortest length? Can infinity occur at all in the cosmos or is it a mathematical construct? Find out more in our podcast with Anthony Aguirre, John D. Barrow and George Ellis.

Cutting the threads of the spacetime fabric and reinstating the aether could lead to a theory of quantum gravity.

To understand how spacetime might have emerged in the early cosmos we need to heat up the equations, and thaw the space and time dimensions.

Space is the stage on which physics happens. It's unaffected by what happens in it and it would still be there if everything in it disappeared. This is how we learn to think about space at school. But the idea is as novel as it is out-dated.

Space is the stage on which physics happens. It's unaffected by what happens inside it and it would still be there if everything in it disappeared. This is how we learn to think about space at school. But the idea is as novel as it is out-dated.

Would you stake your fortune on a 100 to 1 outsider? Probably not. But what if, somewhere in a parallel universe, the straggling nag does come in first? Would the pleasure you feel in that universe outweigh the pain you feel in the one in which you've lost? Questions not dissimilar to this one occupy physicists and for entirely respectable reasons.

Are there parallel universes? Universes in which, rather than reading this article, you are still asleep; in which you are happier, unhappier, richer, poorer, or even dead? The answer is "possibly". It's a controversial claim but one that has won more and more followers over the last few decades.

In the previous article we explored how a clever argument involving gambling makes the idea that there are parallel universes more credible. But does it really?