What a stunning example of the beauty found in ice crystal growth. The exotic needles in this video are seeded on a wire with an applied voltage (the voltage helps align the water molecules into even crystal patterns).
Ice crystals grow by a sort of rule of “least resistance”. Supercooled water vapor will solidify on a surface as ice, that we all know. But tiny, random bumps on that frozen surface mean some water molecules won’t have to travel as far before settling onto the ice. So on and so on, the bump grows into a branch.
As this process is repeated, branches grow upon branches in a chaotic and semi-random pattern called dendritic growth. There are infinite ways for these imperfections, bumps and branches to form, and so no two crystals (or snowflakes) are identical.
Fantastic piece of work.