# Quantum Gravity Lecture

18 July 2018

Nick Evans, Professor of Theoretical High Energy Physics at the University of Southampton, gave a lecture on quantum gravity at the inaugural joint lecture between the Institute of Physics South Central Branch and Bournemouth Natural Science Society on 10 July 2018.

Quantum gravity is perhaps the thorniest subject in modern theoretical physics.

Nick explained how electromagnetism has led to a consistent quantum theory which is the best tested theory in science. Gravity, which at first sight appears very similar to electromagnetism, leads to very strong interactions at high energy and everything breaks down.

Latest observations of gravitational waves confirm Einstein's general relativity theory which describes gravity as a "double copy" of electromagnetism.

Nick then went on to discuss string theory as one possibility for how to make such a double copy and provides a quantum theory of gravity but implies there are 10 space-time dimensions. This throws up many strange ideas such as ‘brane-world’ but we have yet to be able to experimentally probe gravity at quantum distance scales.

This was a very interesting lecture on a subject which we know next to nothing about.

Nick has written a crime adventure novel as part of a particle physics outreach project from the University of Southampton called The Newtonian Legacy, which can be read online or downloaded. He also recently appeared on In Our Time talking about Carl Friedrich Gauss.