## Fibonacci

Anything involving bunny rabbits has to be good.

*The Da Vinci Code*, talks about the "divine proportion" as having a "fundamental role in nature". Brown's ideas are not completely without foundation, as the proportion crops up in the mathematics used to describe the formation of natural structures like snail's shells and plants, and even in Alan Turing's work on animal coats. But Dan Brown does not talk about mathematics, he talks about a number. What is so special about this number?

**Chris Budd**and

**Chris Sangwin**tell us, in 2003 the good old quadratic equation, which we all learned about in school, reached these dizzy pinnacles of fame.

**Kevin Jones**investigates the links between music and mathematics, throwing in limericks, Fibonacci and Scott Joplin along the way.

*Plus*is proud to present an extended version of his winning entry for the THES/OUP 1999 Science Writing Prize.