## Articles

**Phil Wilson**looks at

*constructivist mathematics*, which holds that some things are neither true, nor false, nor anything in between.

**Angus Brown**looks at one of these, a simple model for option pricing, and explains how it takes us on the road to the famous Black-Scholes equation of financial mathematics, which won its discoverers the 1997 Nobel Prize in Economics.

**Colva Roney-Dougal**explores the maths, from chaos to group theory.

*A disappearing number*, a work by Complicite, inspired by the mathematical collaboration of Hardy and Ramanujan.

**Rachel Thomas**went to see the play, and explains some of the maths. You can also read her interview with Victoria Gould about how the show was created.

**John Billingham**investigates and saves the national grid in the process.

**Lewis Dartnell**looks at some stunning examples.

**Peter Markowich**is a mathematician who likes to take pictures. At first his two interests seemed completely separate to him, but then he realised that behind every picture there is a mathematical story to tell.

*Plus*went to see him to find out more, and ended up with a pictorial introduction to partial differential equations.