## Articles

Are the unchanging features of the Universe really unchanging?

**Oli Freke**has always been fascinated by sine waves, so much so that he's created a song based on them for the Geekpop festival, which is currently taking place on the Web. In this article he explores his song, touching on ancient Greek mythology, strange piano tunings and Johann Sebastian Bach.

**Jerry Gollub**tells

*Plus*about a new discovery which combines experiment with sophisticated maths.

**Carola Schönlieb**explores how mathematicians use the heat equation to fill in the gaps.

**David Spiegelhalter** and **Mike Pearson** explore how risk can be spun and there's an interactive animation for you to have a go yourself.

*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.

**Phil Wilson**looks at

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