Who invented zero? Why are there 60 seconds in a minute? Can a Butterfly's wings really cause a storm on the far side of the world? In 50 concise essays, professor Tony Crilly Explains the mathematical concepts that allo...Who invented zero? Why are there 60 seconds in a minute? Can a Butterfly's wings really cause a storm on the far side of the world? In 50 concise essays, professor Tony Crilly Explains the mathematical concepts that allow use to understand and shape the world around us.