Taken from the 25th anniversary issue of Physics World, this article examines one of the five biggest unanswered questions in physics as selected by the magazine’s editors Scientists and philosophers ...

Few ideas in modern science have reshaped our understanding of reality more profoundly than space-time—the interwoven fabric ...

What is time? If you're a practising physicist, it's a quantity in your equations, t. This is the variable that you use for one of the four dimensions of the manifold of space-time, the term ...

But it is boring in comparison to the larger questions about space and time. Discussing what space and time are and where they came from is now within the realm of particle physics.

What Is The Time? The concept of time feels so natural that we often forget just how peculiar it is. What actually is time? Figuring it out remains one of the trickiest problems in physics.

The ability to jump forward and backwards in time has long fascinated science fiction writers and physicists alike. So is it really possible to travel into the past and the future?

What existed before the big bang? What is the nature of time? Is our universe one of many? On the big questions science cannot (yet?) answer, a new crop of philosophers are trying to provide answers.

A billion billion attoseconds just passed while you read this. Why is such a tiny timeframe crucial to this year's Nobel physics prize winners?

Neils Bohr once said “Physics concerns what we can say about Nature." Neils Bohr said, “It is wrong to think that the task of physics is to find out how Nature is. Physics concerns what we can ...