String theory is often considered to be one of the most difficult branches of modern physics. However, it is far from an impenetrable subject and the basic ideas can be understood by anyone.

String theory is the result of a long-time trend in physics to attempt to arrive at unified theories of seemingly distinct phenomena. The great successes of twentieth century physics have been general relativity – which explains how gravity behaves at large scales – and the standard model – which explains the subatomic world.

However, it has been difficult to see how these two theories work together – for example, we do not know how gravity works for subatomic particles. String theory was created to describe subatomic particles called mesons – however it was also found to naturally ‘predict’ gravity. It is therefore hoped that it can be the missing ‘Theory of Everything’.

Even if it is not correct as a fundamental theory in and of itself, the mathematics of string theory is very interesting. The so-called AdS/CFT correspondence is a trick that uses this new mathematics to simplify complicated calculations in areas such as high energy physics and solid state physics.