What gives an equation the right to call itself a law?
What makes a number a constant of nature?
Why cosmologists worry about isolated brains that randomly fluctuate into existence.
Why game theory is a serious business.
George Ellis explains why the study of the cosmos poses some very deep questions.
The winner of the 2014 Chern medal tells us about beauty in maths, the twists and turns of mathematical history, and his work for the maths community.