Claudia de Rham has rather an unusual relationship with gravity.

While she has spent her career exploring its fundamental nature, much of her free time has involved trying to defy it - from scuba diving in the Indian Ocean to piloting small aircraft over the Canadian waterfalls. Her ultimate ambition was to escape gravity’s clutches altogether and become an astronaut, a dream that was snatched away by an unlikely twist of fate.

However, Claudia has no regrets - and says defying gravity for much of her life has helped her to truly understand it.

As Professor of theoretical physics at Imperial College London, she now grapples with deep mathematics, where the fields of particle physics, gravity and cosmology intersect, on a quest to understand how the universe really works. She is a pioneer of the theory of massive gravity, a theory which could take us beyond even Einstein’s theory of relativity and shed light on why the universe is expanding at an ever-increasing rate.

Presented by Jim Al-Khalili
Produced for BBC Studios by Beth Eastwood
Reversion for World Service by Minnie Harrop