Content about “
relativity

Article
hourglass with clock behind

What is time?

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?
Podcast

What is time: The podcast

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.
News story

Spacetime does ripple

Physicists have finally detected the gravitational waves they have been chasing for nearly 100 years.
Collection

Celebrating general relativity

A hundred years ago, on 25 November 1915, Einstein first presented his general theory of relativity. We explore this famous theory and what it says about the world we live in.
Podcast

What is a black hole – physically?

We asked cosmologist Pau Figueras everything we’ve ever wanted to know about black holes. In this podcast he explains what black holes are, physically, and how we hope to observe them.