“No two snowflakes are alike.” This is a statement nearly every schoolchild has heard at least once, either while crafting unique snowflakes with a sheet of folded paper and some scissors or while learning a lesson on the science of snow. While even most scientists don’t quite understand what causes a snowflake to form such complex and beautiful columns and points and branches, one thing is for certain, the composition of snowflakes guarantees that no two will ever be identical. However, it is possible for two snowflakes to appear to be nearly exactly alike.
A snowflake begins to form when a piece of dust catches water vapor out of the air. Water is created when two hydrogen molecules attach to an oxygen molecule. The two hydrogen molecules are angled from one another in such a way that they form a hexagonal shape when they come together during the freezing process; thus, a snowflake begins as a simple hexagonal shape or as layers of hexagons called diamond dust. The emergent properties that follow from the original hexagon are what differentiate one snowflake from another, as the humidity, the temperature in the air, and many other factors (some of which remain unclear to scientists) allow each snowflake to form in an entirely unique way with a seemingly endless variety of shapes.
However, in 1988, a scientist named Nancy Knight claimed to have located two that were the same while studying snowflakes as part of an atmospheric research project. And it appeared to be so; when put under a microscope, the emergent properties looked nearly identical. But while it is feasible that two snowflakes can appear to be exactly alike on the outside, they are never identical on an atomic level. Deuterium is an atom that appears attached to about one in every 3000 hydrogen molecules in the air. Because there are millions of atoms that make up a snowflake, the random assortment of deuterium in any two snowflakes—even in two that so very closely resemble one another—simply cannot be the same.
Here at Climate Masters, we’d like to remind you to grab a cup of cocoa and relax with your family this holiday, perhaps by crafting some unique snowflake creations of your own. We wish you a very happy holiday season, from our family to yours!