Speaker 1: Welcome to brain Stuff, a production of iHeart Radio, Hey
Speaker 1: brain Stuff, Lauren vogel Bomb. Here consider the long and
Speaker 1: arduous plight of the snowflake. Those delicate, intricate crystals have
Speaker 1: traveled many miles before they plummet to the ground alongside
Speaker 1: their trillions of cousins, And although they fly in multitudes,
Speaker 1: the word on the snow slipped street is that no
Speaker 1: two are exactly alike. But can every snowflake really be different?
Speaker 1: The short answer is yes, every snowflake really is unique,
Speaker 1: but you might find some that are exceedingly similar, particularly
Speaker 1: at the beginning of a flake's development. But fully formed
Speaker 1: snowflakes are indeed structurally different, if only by the tiniest
Speaker 1: of degrees. Understanding why snowflakes take unique forms means understanding
Speaker 1: how they're formed in the first place. It all starts
Speaker 1: at Earth's surface, as water evaporates from oceans, rivers, and
Speaker 1: lakes and rise into the atmosphere in the form of
Speaker 1: gaseous water vapor, which we sometimes see as clouds. In
Speaker 1: the summertime, those clouds drift around the skies, providing shade
Speaker 1: and breaking up the blue horizon. But in winter things change.
Speaker 1: The cold air forces molecules of water vapor into little
Speaker 1: liquid droplets that condensed onto any nearby particulate matter such
Speaker 1: as pollen or dust. These tiny ice crystals are the
Speaker 1: baby virgins of what soon may become full grown snowflakes.
Speaker 1: The crystals float through the sky and collide with molecules
Speaker 1: of water vapor. As vapor contacts the crystals, the water
Speaker 1: vapor skips from its state as a gas straight to
Speaker 1: a solid crystal, adding to the original nucleus of the snowflake.
Speaker 1: This process happens over and over again, building the snowflake
Speaker 1: from a nearly imperceptible crystal into a larger flake that,
Speaker 1: given the right conditions, falls to the ground. And knowing
Speaker 1: all of this, it may still be difficult to believe
Speaker 1: that in a sky full of snowflakes, no two are alike,
Speaker 1: but the flake making process practically ensures that these tiny
Speaker 1: crystals are all unique, even when they fall by the billions.
Speaker 1: As the very first ice crystals come together in a
Speaker 1: group of fledgling snowflakes, the new flakes often look strikingly similar.
Speaker 1: That's largely due to the fact that ice crystals typically
Speaker 1: take a hexagonal or six sided lattice shape because of
Speaker 1: the way that hydrogen atoms bond with oxygen to make water,
Speaker 1: but certain edges of the ice crystals will be jagged.
Speaker 1: These uneven areas attract more water molecules than the smoother
Speaker 1: parts of the hexagon. Each little arm will sprout more
Speaker 1: of the same, growing into an intricate and uniform snowflake.
Speaker 1: If snowflake development stopped within the first few moments of birth,
Speaker 1: we'd wind up with a lot more flakes that look alike.
Speaker 1: But snowflakes keep gathering more and more crystals, which clustered
Speaker 1: together on top of one another indistinct patterns. As those
Speaker 1: clusters of crystals continue their snowflake fiesta, other guests visit
Speaker 1: the flake making party. Notably, humidity and temperature both play
Speaker 1: major roles and whether the snowflake gets bigger and bigger
Speaker 1: or fizzles out. As you can probably imagine, temperature is
Speaker 1: critical to ice crystal formation and structure. Between temperatures of
Speaker 1: twenty seven and thirty two degrees fahrenheit that's negative two
Speaker 1: point eight and zero celsius a, crystals take on a
Speaker 1: plate like or prism like appearance. These are your prototypical
Speaker 1: six armed snowflakes that don't have a lot of extra pizzas.
Speaker 1: Drop the temperature a few degrees though, and you'll see
Speaker 1: needle like structures starting to form a little lower and
Speaker 1: hollow columns develop, and even colder, you'll see stars sprouting
Speaker 1: fern like arms. Meanwhile, lower humidity tends to result in
Speaker 1: flatter flakes. Higher humidity means more crystal development in edges
Speaker 1: on corners. So add some extra moisture at those really
Speaker 1: frigid temperatures, and suddenly snowflakes may become mesmerizingly beautiful. They
Speaker 1: can contain a multitude of intersecting plates and needles and
Speaker 1: spaces a minute masterpieces falling from the heavens. Okay, So,
Speaker 1: physics and weather conditions determine snowflakes shape and size, but
Speaker 1: math determines that those flakes are unique. Consider that each
Speaker 1: snowflake is made up of a huge number of water molecules.
Speaker 1: By one estimate, as many as a quintillion molecules per flake.
Speaker 1: Because each little branch of a snowflake can spawn many others,
Speaker 1: there are dozens and dozens of ways for various crystalline
Speaker 1: features to join. There are so many possible arrangements that
Speaker 1: some scientists say there are twice as many possible crystal
Speaker 1: combinations as there are atoms in the whole universe. Those
Speaker 1: kinds of numbers are so large that we can't really
Speaker 1: even comprehend them. But if the math holds, those numbers
Speaker 1: mean that it is awfully unlikely that any two snowflakes
Speaker 1: have ever been, or ever will be exactly alike. Furthermore,
Speaker 1: there are all kinds of other factors at play in
Speaker 1: snowflake formation. At any given instance. Even the tiniest fluctuation
Speaker 1: and temperature and humidity alters crystal construction a miniature. Impurities
Speaker 1: like flux of dust change the crystals too. The angles
Speaker 1: with which water molecules collide with existing crystals matter as well,
Speaker 1: and snowflakes smash into each other as they zoom and
Speaker 1: swoop through the air, where their branches shatter new one's form,
Speaker 1: adding to the uniqueness of every translucent little flake in
Speaker 1: the swirling atmosphere miles above Earth's surface. All of these
Speaker 1: variables ceaselessly change. Conditions that hold in one small space
Speaker 1: are just a tiny bit different than those inches away
Speaker 1: in any direction, and all of it transforms crystals and
Speaker 1: their subsequent snowflakes in infinite ways, so snowflakes really are
Speaker 1: nearly unlimited in their specialness. They're tiny and ephemeral testaments
Speaker 1: of the strange and constant change in the world and
Speaker 1: universe all around us. Today's episode is based on the
Speaker 1: article is every snowflake Actually Unique? On how stuff works
Speaker 1: dot com? Written by Nathan Chandler. Brainstuff is production by
Speaker 1: Heart Radio in partnership with how stuff works dot Com,
Speaker 1: and it's produced by Tyler Clang. For more podcasts for
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