Dan Brown in his book, 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?
It isn't often that a mathematical equation makes the national press, far less popular radio, or most astonishingly of all, is the subject of a debate in the UK parliament. However, as 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.