## graph theory

How many possible genetic relationships are there between a collection of different species? The answer is mind-bogglingly large.

A famous question involving networks appears to have come closer to an answer.

Asking good questions is an important part of doing maths. But what makes a good question?

Sometimes a piece of maths can be so neat and elegant, it makes you want to shout "eureka!" even if you haven't produced it yourself. One of our favourite examples is the art gallery problem.

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?

How a cute 18th century puzzle laid the foundations for one of the most modern areas of maths: network theory.

We've read the book. We've bought the T-shirt. And now, finally, here it is: the movie of one of our favourite maths problems

How to make a hard problem easy by changing the way you look at it.

The London Underground turns 150 today! It's probably the most famous rail network in the world and much of that fame is due to the iconic London Underground map. But what makes this map so special?

Mathematicians and psychologists don't cross paths that often and when they do you wouldn't expect it to involve an (apparently) unassuming puzzle like the Tower of Hanoi. Yet, the puzzle holds fascination in both fields.