Taking on a much more “classic” snowflake feel, I thought this one would be perfect for the holidays. :) There are still layers of interesting details here even though it’s a design we’re familiar with – read on!
Start by imagining the snowflake as a tiny hexagon – the region of the center of this crystal that’s a middle grey colour. It’s simple – very little detail, solid edges, no surface features. To say quintillions of snowflakes would be similar is plausible, so the statement “no two snowflakes are alike” breaks down at a certain point, like saying that no two people are alike, even though we are pretty much indistinguishable aside from genetics when we’re an egg in an ovary. Heck, even identical twins have different fingerprints!
Conditions in a cloud, no matter how stable, never stay constant for long. If the humidity was lower, the snowflake might have grown thicker. This means that the distance between the centers of the prism facets (the thin ones on all sides) and the outer edges grows bigger. The larger this delta, the more likely that the outer edges will grow faster than the center, creating cavities in the ice. This can end up splitting the entire snowflake into two new planes of growth, which we see here. That brighter hexagonal area? That’s two layers of ice, not one. More layers of ice allow for more reflectivity of the flash back through the camera lens! Just as things separate, however, things can recombine as conditions change.
Imagine now that the snowflake is growing so large that the corners will collect much more water vapour than the inner sides. Branches begin to form, but in such stable conditions they grow slowly and sometimes reconnect back together – forming a type of snowflake we call a “sectored plate”. We can see some vestigial side-branches near the center, inside the footprint of the larger hexagonal center. We see this same fusing behaviour with the larger side-branches as well – growing so close together that they recombine, forever holding hands as the snowflake continues to grow.
Every step of this journey is a physics lesson. It can all be figured out like a curious little puzzle and a few simple rules. This is one of the reasons why I never tire of snowflakes: they form by the trillions, each with their own story to tell from the same basic ingredients. Some are ugly, some beautiful, and my favourite ones are enigmatic. Look closely in the lower right and you’ll see a stowaway snowflake, formed originally by a center column that then grew into two competing plates! Everywhere you look, there is an infinitesimal story being written for those that care to read.
Even if you cannot see these stories with your own eyes, the simple understanding that they are all around us makes the world a more beautiful place.
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