Question: what is string theory?

Euan Allen answered on 18 Jun 2016:

Hi Lolaf – wow, tough question!

Lots of people are currently trying to come up with a theory of everything. What I mean by this is an equation or set of equations (a theory) that we can use to make predictions about anything in the world, from the interaction of single particles like electrons, right up to black holes and the universe as a whole.

So far nobody has been able to produce such a theory that can describe everything. String theory is an attempt to have such a theory, and its basic principal is that everything in the world is made up of tiny strings that twist and knot. The theory did appear to work well for a while, but has recently had a few results where people now think it might not be true, and we maybe need a different theory.