Can we always find order in systems that are disordered? Imre Leader says yes.

Meet the number that's bigger than the observable Universe!

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?

Suppose you have an infinitely large sheet of paper (mathematicians refer to this hypothetical object as the plane). You also have a number of different colours - pots of paint, perhaps. Your aim is to colour every point on the plane using the colours available. That is, each point must be assigned one colour.

Sometimes a mathematical object can be so big that, however disorderly we make the object, areas of order are bound to emerge. Imre Leader looks at the colourful world of Ramsey Theory.