Is cold the new hot?

Why temperatures below absolute zero don't break thermodynamics: a primer on entropy, negative temperature, and what 'hot' really means.

Gravitational Slingshots

An intuitive explanation of gravitational slingshots: how space probes gain speed from a planet's motion without violating energy conservation.

A case study in choosing algorithms

A lesson from parallelizing terabytes of dark matter simulation data: why a dynamic work pool beat a bin-packing pre-partitioning scheme.