You've been told that "no two snowflakes are alike" more times
than you can count. But is that actually the case? And if
so—why? Fortunately, Joe Hanson of It's Okay to Be Smart has
done us the favor of breaking down the science of snowflakes,
how they become so intricate, and why, even though some may
appear similar, looks can be deceiving.  As it turns out,
snowflakes are complicated little buggers. Take a few hexagons
of water molecules, throw in randomness, and you've got a
seemingly infinite number of snowflake shapes at your
fingertips. All further proof that, if you know where to look,
physics can be absolutely beautiful. [YouTube]