“The universe isn’t mysterious – there are just things about it that we don’t (yet) understand.” – Jim Al-Khalili

Why does physics matter? What can the study of energy and force, of matter and its motion and behaviour through space and time teach us about the universe and the nature of reality itself? According to Jim Al-Khalili, the renowned physics professor and host of BBC Radio 4’s The Life Scientific, we all need to understand the three pillars of modern physics — quantum theory, relativity and thermodynamics — if we are ever to have a full grasp of reality and our place in this universe.

For over two thousand years we have tried to understand how and why our world is the way it is: Where did it come from? What is it made of? How does it work? According to Al-Khalili, physics is a quest to answer these questions. And like the transformative discoveries in physics that the birth of quantum mechanics and relativity brought us a century ago — discoveries which altered the course of human history — Al-Khalili believes that we may soon be on the verge of another revolution in physics.

But there’s still so much that we don’t understand — we know very little about the nature of the dark energy that is ripping the universe apart, and we have no answers to fundamental questions like why there is more matter than antimatter, why the properties of the universe are so finely tuned to allow for stars, planets and life to exist, whether there are multiple universes or whether there was anything before the big bang.

These are all questions that Al-Khalili addresses in his new book The World According to Physics. He joined us in January 2021, in conversation with fellow physicist and science communicator Helen Czerski, to discuss how physics both humbles and empowers us.