## Articles

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

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

**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.

**Yutaka Nishiyama**illuminates the connection between light bulbs, logic and binary arithmetic.