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The SIGGRAPH 2005 demo of dual photography from Stanford, which swaps the roles of projector and camera to render a scene from the light's point of view. It includes the reveal of a hidden playing card.

Psychologist Philip Zimbardo explains how ordinary people can be pushed into doing evil by situations and systems. He draws on the Stanford prison experiment and unseen Abu Ghraib photos, then turns to the opposite case: how ordinary people can become heroes.

Historian Doron Swade tells the story of Charles Babbage's quest to build the Difference Engine and the construction of Difference Engine No. 2 at the Science Museum. The talk covers Babbage's motivation, his machines and Ada Lovelace's insight into the Analytical Engine.

A short BBC clip narrated by David Attenborough showing crows in Japan using city traffic to crack nuts, dropping them at intersections and retrieving them when the light changes.