When we think about designer things, we rarely think about snowflakes. But it turns out scientists can make designer snowflakes come to life. And snowflakes are way more complex and mysterious than they may seem at first. Just ask the scientist who helped create Frozen’s snow.
In the above video YouTuber Derek Muller, a scientist and educator, interviews Dr. Ken Libbrecht, a professor of physics at Caltech. (And snowflake consultant on Frozen.) Muller, a.k.a. Veritasium, interviews Libbrecht, clarifying his job as a “snowflake artist” of sorts.
As Libbrecht notes, he designs all of his snowflakes on the computer by hand. Subsequently, all of his designs are as unique as those of real snowflakes. The professor can then use a chilly contraption—a sort of freezer box with adjustable air pressure, water vapor, humidity, etc., that Librrecht can control—to “grow” the snowflakes.
Muller and Libbrecht go deep into the science behind snowflake construction. In essence, Muller notes that the icy flakes form when water evaporates into the air and individual H2O molecules begin bouncing around in the atmosphere. As the vapor rises, it cools and becomes supersaturated. This means more water molecules take to the air than otherwise would at an equilibrium temperature. The water molecules then condense on dust particles to form tiny droplets. The tiny droplets, in turn, form hexagonal seed crystals.
As for how those seed crystals take on their unique flake shapes, that comes down to quantum physics. Muller notes that the hexagonal structure the water molecules lock into results from their peculiar properties. Oxygen atoms attract electrons more than hydrogen atoms do. And since H2O molecules have a “bent shape,” they’re polar, with oxygen atoms being slightly negative and hydrogen ones, slightly positive.
These polarized molecular lattices then grow into visible hexagonal crystals. Depending on the shapes of the perimeters of the hexagonal crystals—that is, depending on which parts of their sides are rough or smooth—other water molecules will either cling onto, or bounce off of, them. Where its edges are rough, a seed crystal will sprout icy arms. Where they’re smooth, none will appear.
At around 11 minutes in the video, Libbrecht shows how he can make “almost identical” snowflakes in the lab. Using his cooling contraption, which uses a sapphire disk in lieu of dust particles, the professor reveals he’s able to make “identical twin” designer snowflakes. Libberecht says they’re just like identical human twins: “They’re not exactly the same,” the professor says, “but clearly more alike than you’d ever expect.”
This leaves us wondering if Elsa can make identical snowflakes with her powers. Guess we’ll have to take a magnifying glass to Frozen‘s snow.