The Science of Snowflakes

We know that snowflakes are ice crystals that form in the atmosphere from water vapor. We've also heard that no two snowflakes are alike, but how would we ever prove that? Only a miniscule percentage of the world's snowflakes will ever be examined, and if they don't melt immediately, they are mashed up with all those other flakes that we shovel from our driveways. Another thing we know is that snowflake crystals form in six-sided shapes, hexagons to be exact, but why is that? Johannes Kepler thought snowflakes had something in common with the hexagons of a beehive, which is an intriguing idea. Physicist Brian Cox explains exactly why snowflakes form in a hexagon, and why we find them beautiful in this pleasantly charming video from the Royal Society. (via Kottke)