The universe is expanding at an accelerating rate but Einstein’s theory of General Relativity and our knowledge of particle physics predict that this shouldn’t be happening. Most cosmologists pin their hopes on Dark Energy to solve the problem. But, as Claudia de Rham argues, Einstein’s theory of gravity is incorrect over cosmic scales, her new theory of Massive Gravity limits gravity’s force in this regime, explains why acceleration is happening, and eliminates the need for Dark Energy.

You can see Claudia de Rham live, debating in ‘Dark Energy and The Universe’ alongside Priya Natarajan and Chris Lintott and ‘Faster Than Light’ with Tim Maudlin and João Magueijo at the upcoming HowTheLightGetsIn Festival on May 24th-27th in Hay-on-Wye.

This article is presented in association with Closer To Truth, an esteemed partner for the 2024 HowTheLightGetsIn Festival.

The beauty of cosmology is that it often connects the infinitely small with the infinitely big – but within this beauty lies the biggest embarrassment in the history of physics.

According to Einstein’s theory of General Relativity and our knowledge of particle physics, the accumulated effect of all infinitely small quantum fluctuations in the cosmos should be so dramatic that the Universe itself should be smaller than the distance between the Earth and the Moon. But as we all know, our Universe spans over tens of billions of light years: it clearly stretches well beyond the moon.

This is the “Cosmological Constant Problem”. Far from being only a small technical annoyance, this problem is the biggest discrepancy in the whole history of physics. The theory of Massive Gravity, developed by my colleagues and I, seeks to address this problem.