This lecture was recorded at the Ri on 24 November 2025.

For the last century, physics has been following the paths set out by the same two theories—quantum mechanics and general relativity—and, let’s face it, it’s getting pretty boring. Despite these great theories being fundamentally in conflict, most scientists are simply chasing decimal points in laboratories. To give the deeper explanation of reality we seek, we need new ways to explore and critique our best ideas of the universe on the smallest and largest scales.

In this talk, physicist Vlatko Vedral presents a number of key thought experiments that test the foundations of physics, namely the interface between quantum physics and general relativity. General relativity is our best theory of gravity, and it remains a completely classical theory despite many attempts to quantize it. Some of the thought experiments are aimed at testing how quantum physics changes the concepts of space and time that are key to understanding general relativity, while others explore how the key principle of general relativity, the so-called equivalence principle, could affect quantum physics and lead to its modification.

Join Vlatko to discover how the realisation of these theories could transform our understanding of quantum physics.