pi

A two-minute animation of an Alan Watts talk arguing that life is like music: it is meant to be danced to in the moment, not rushed toward a final goal. It is a short, accessible take on living in the present.

A short clip from Carl Sagan's Cosmos in which he explains how Eratosthenes measured the circumference of the Earth using shadows in two Egyptian cities. It is a clear, visual account of an ancient scientific feat.

Ward Cunningham explains the history and intent of the debt metaphor, which he coined while refactoring the WyCash product. He says debt means code reflecting an incomplete understanding of the problem, not sloppy programming.

The first video in potholer54's climate series, giving a basic look at how climate scientists infer that man-made carbon gases are changing the climate. It is a short explainer meant to present the scientific evidence plainly.

A Hitachi promotional cartoon in the style of Schoolhouse Rock explaining perpendicular magnetic recording for hard drives.

A three-minute excerpt from Milton Friedman's Free to Choose in which he uses a pencil to show that no single person knows how to make it. He argues that the free market coordinates countless strangers peacefully.

Michael Wesch's five-minute video about Web 2.0, showing how the read/write web, XML and user-generated content change how people create and share information.

David Spiegelhalter, Professor of the Public Understanding of Risk, uses statistics to weigh everyday risks such as bacon sandwiches and cycling. The six-minute piece introduces micromorts as a way to compare the risk of dying.