## Articles

**Colva Roney-Dougal**takes us into their abstract world and puzzles over a game of Solitaire.

**Phil Wilson's**article, which explores the maths behind a cold war in slug world.

**Yutaka Nishiyama**explains why, and how beautiful mathematical oddities can inspire us to discover new mathematics.

**Gregory Chaitin**explains why he thinks that Gödel's incompleteness theorem is only the tip of the iceberg, and why mathematics is far too complex ever to be described by a single theory.

**Chris Budd**investigates.

**Christine Currie**explains how your airfare is calculated.