Physics
Brownian Motion
Quick fact
The theory explaining Brownian motion was published by Albert Einstein in 1905—the same year he published his papers on special relativity and the photoelectric effect—and it helped convince the scientific world that atoms were real.
Why this is interesting
Ever noticed how a tiny speck of dust dances erratically in a sunbeam? That dance—unpredictable, ceaseless—is a direct glimpse into the hidden world of atoms and molecules. What causes this eternal jitter?