Plenty of room at the bottom

On this day in 1959, the physicist Richard Feynman gave a talk to other scientists in California about building things very, very small. He asked whether a whole encyclopedia could be written on the head of a pin, and he offered prizes to anyone who could build a tiny motor or shrink a page of writing.

Why it mattered

His talk is often remembered as the start of nanotechnology, the science of building things almost as small as atoms.