Can we always find order in systems that are disordered? If so, just how large does a system have to be to contain a certain amount of order? In this video Imre Leader of the Department of Pure Mathematics and Mathematical Statistics at the University of Cambridge gives an equation free introduction to a fascinating area of maths called *Ramsey theory*.

This talk was originally given to an audience of Year 12 A-level maths students (aged 16-17) in June this year and formed part of a mathematics enrichment day organised by the Millennium Mathematics Project with a special focus on encouraging the development of mathematical thinking.

Intrigued? You can read a brief description of Ramsey theory or find out more in our more detailed article. And you can also find out how Ramsey theory gives us one of our favourite numbers.