View full lesson: http://ed.ted.com/lessons/sunlight-is-way-older-than-you-think-sten-odenwald

It takes light a zippy 8 minutes to reach Earth from the surface of the Sun. But how long does it take that same light to travel from the Sun’s core to its surface? Oddly enough, the answer is many thousands of years. Sten Odenwald explains why by illustrating the random walk problem.

Lesson by Sten Odenwald, animation by TOTEM Studio.