comma.ai

A two-minute Rouxbe cooking-school demo of how to heat a pan properly before cooking. It uses the Leidenfrost effect, where water beads and skates across a hot pan, to show when a stainless steel pan is ready.

A 1930s Chevrolet training film explaining the principles and development of the differential gear. It builds the idea step by step from first principles to the finished mechanism.

A short video of stretching and hand exercises for preventing and easing tendinitis and carpal tunnel syndrome, from a percussion teacher. The exercises were shown to him by a doctor.

A motorcycle safety video on the SMIDSY (sorry mate, I didn't see you) accident, explaining the perception and optical illusion that makes drivers fail to see riders, and how riders can spot the signs and avoid it.