Today at lunch I was asked one of the questions that nonsense theorists are often asked: so what does this have to do with the real world?
Of course, one could always launch into a (now fashionable) tirade about protocols for quantum information, or two dimensional systems and topological quantum field theories. However, since the conversation was set more in the context of quantum gravity, and the asker was mostly looking for a very simple, one line answer (after having already suffered a five minute introduction to category theory), I was at a loss to find the right words.
So here is the challenge: can you summarize categorical quantum gravity
in 20 catchy words or less? We assume that our readers will not
be captivated by statements along the lines of Everything is made of Strings
or, more pertinently, the speed of light varies
(although that is, of course, true). Rather, the phrase should capture the potential of quantum gravity to describe aspects of the world completely outside the domain of established physical theory.