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**Anna Faherty**takes us on a tour of his work.

**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.

**Julian Havil**looks at a little-known algorithm that sieves out all primes up to a given number, and which is astonishing in its simplicity.

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