1 00:00:01,800 --> 00:00:06,920 Speaker 1: Welcome to brain Stuff, a production of iHeart Radio, Hey 2 00:00:07,000 --> 00:00:11,280 Speaker 1: brain Stuff, Lauren vogel Bomb. Here consider the long and 3 00:00:11,440 --> 00:00:16,360 Speaker 1: arduous plight of the snowflake. Those delicate, intricate crystals have 4 00:00:16,440 --> 00:00:19,880 Speaker 1: traveled many miles before they plummet to the ground alongside 5 00:00:19,880 --> 00:00:23,920 Speaker 1: their trillions of cousins, And although they fly in multitudes, 6 00:00:24,239 --> 00:00:26,479 Speaker 1: the word on the snow slipped street is that no 7 00:00:26,640 --> 00:00:31,200 Speaker 1: two are exactly alike. But can every snowflake really be different? 8 00:00:32,280 --> 00:00:35,400 Speaker 1: The short answer is yes, every snowflake really is unique, 9 00:00:35,640 --> 00:00:39,000 Speaker 1: but you might find some that are exceedingly similar, particularly 10 00:00:39,040 --> 00:00:41,920 Speaker 1: at the beginning of a flake's development. But fully formed 11 00:00:41,920 --> 00:00:46,000 Speaker 1: snowflakes are indeed structurally different, if only by the tiniest 12 00:00:46,040 --> 00:00:52,600 Speaker 1: of degrees. Understanding why snowflakes take unique forms means understanding 13 00:00:52,640 --> 00:00:55,520 Speaker 1: how they're formed in the first place. It all starts 14 00:00:55,520 --> 00:00:59,040 Speaker 1: at Earth's surface, as water evaporates from oceans, rivers, and 15 00:00:59,120 --> 00:01:01,680 Speaker 1: lakes and rise into the atmosphere in the form of 16 00:01:01,720 --> 00:01:05,720 Speaker 1: gaseous water vapor, which we sometimes see as clouds. In 17 00:01:05,760 --> 00:01:09,120 Speaker 1: the summertime, those clouds drift around the skies, providing shade 18 00:01:09,120 --> 00:01:13,319 Speaker 1: and breaking up the blue horizon. But in winter things change. 19 00:01:13,480 --> 00:01:17,120 Speaker 1: The cold air forces molecules of water vapor into little 20 00:01:17,120 --> 00:01:21,480 Speaker 1: liquid droplets that condensed onto any nearby particulate matter such 21 00:01:21,480 --> 00:01:25,560 Speaker 1: as pollen or dust. These tiny ice crystals are the 22 00:01:25,600 --> 00:01:29,720 Speaker 1: baby virgins of what soon may become full grown snowflakes. 23 00:01:31,200 --> 00:01:34,080 Speaker 1: The crystals float through the sky and collide with molecules 24 00:01:34,080 --> 00:01:37,760 Speaker 1: of water vapor. As vapor contacts the crystals, the water 25 00:01:37,840 --> 00:01:40,760 Speaker 1: vapor skips from its state as a gas straight to 26 00:01:40,800 --> 00:01:44,400 Speaker 1: a solid crystal, adding to the original nucleus of the snowflake. 27 00:01:45,080 --> 00:01:48,960 Speaker 1: This process happens over and over again, building the snowflake 28 00:01:49,040 --> 00:01:52,800 Speaker 1: from a nearly imperceptible crystal into a larger flake that, 29 00:01:53,040 --> 00:01:56,760 Speaker 1: given the right conditions, falls to the ground. And knowing 30 00:01:56,800 --> 00:01:59,160 Speaker 1: all of this, it may still be difficult to believe 31 00:01:59,240 --> 00:02:02,080 Speaker 1: that in a sky full of snowflakes, no two are alike, 32 00:02:02,760 --> 00:02:06,559 Speaker 1: but the flake making process practically ensures that these tiny 33 00:02:06,600 --> 00:02:09,800 Speaker 1: crystals are all unique, even when they fall by the billions. 34 00:02:11,440 --> 00:02:14,360 Speaker 1: As the very first ice crystals come together in a 35 00:02:14,400 --> 00:02:18,560 Speaker 1: group of fledgling snowflakes, the new flakes often look strikingly similar. 36 00:02:19,200 --> 00:02:21,960 Speaker 1: That's largely due to the fact that ice crystals typically 37 00:02:21,960 --> 00:02:25,160 Speaker 1: take a hexagonal or six sided lattice shape because of 38 00:02:25,160 --> 00:02:28,120 Speaker 1: the way that hydrogen atoms bond with oxygen to make water, 39 00:02:29,560 --> 00:02:32,320 Speaker 1: but certain edges of the ice crystals will be jagged. 40 00:02:32,919 --> 00:02:36,600 Speaker 1: These uneven areas attract more water molecules than the smoother 41 00:02:36,720 --> 00:02:40,320 Speaker 1: parts of the hexagon. Each little arm will sprout more 42 00:02:40,360 --> 00:02:44,080 Speaker 1: of the same, growing into an intricate and uniform snowflake. 43 00:02:45,919 --> 00:02:49,280 Speaker 1: If snowflake development stopped within the first few moments of birth, 44 00:02:49,480 --> 00:02:51,960 Speaker 1: we'd wind up with a lot more flakes that look alike. 45 00:02:52,480 --> 00:02:56,160 Speaker 1: But snowflakes keep gathering more and more crystals, which clustered 46 00:02:56,200 --> 00:03:00,320 Speaker 1: together on top of one another indistinct patterns. As those 47 00:03:00,320 --> 00:03:04,720 Speaker 1: clusters of crystals continue their snowflake fiesta, other guests visit 48 00:03:04,760 --> 00:03:09,800 Speaker 1: the flake making party. Notably, humidity and temperature both play 49 00:03:09,880 --> 00:03:12,480 Speaker 1: major roles and whether the snowflake gets bigger and bigger 50 00:03:12,680 --> 00:03:17,200 Speaker 1: or fizzles out. As you can probably imagine, temperature is 51 00:03:17,400 --> 00:03:22,200 Speaker 1: critical to ice crystal formation and structure. Between temperatures of 52 00:03:22,240 --> 00:03:25,560 Speaker 1: twenty seven and thirty two degrees fahrenheit that's negative two 53 00:03:25,600 --> 00:03:28,760 Speaker 1: point eight and zero celsius a, crystals take on a 54 00:03:28,880 --> 00:03:32,880 Speaker 1: plate like or prism like appearance. These are your prototypical 55 00:03:33,080 --> 00:03:36,360 Speaker 1: six armed snowflakes that don't have a lot of extra pizzas. 56 00:03:37,680 --> 00:03:40,200 Speaker 1: Drop the temperature a few degrees though, and you'll see 57 00:03:40,400 --> 00:03:44,160 Speaker 1: needle like structures starting to form a little lower and 58 00:03:44,280 --> 00:03:49,520 Speaker 1: hollow columns develop, and even colder, you'll see stars sprouting 59 00:03:49,560 --> 00:03:55,240 Speaker 1: fern like arms. Meanwhile, lower humidity tends to result in 60 00:03:55,400 --> 00:03:59,840 Speaker 1: flatter flakes. Higher humidity means more crystal development in edges 61 00:04:00,120 --> 00:04:04,280 Speaker 1: on corners. So add some extra moisture at those really 62 00:04:04,320 --> 00:04:09,600 Speaker 1: frigid temperatures, and suddenly snowflakes may become mesmerizingly beautiful. They 63 00:04:09,600 --> 00:04:12,920 Speaker 1: can contain a multitude of intersecting plates and needles and 64 00:04:13,000 --> 00:04:19,160 Speaker 1: spaces a minute masterpieces falling from the heavens. Okay, So, 65 00:04:19,320 --> 00:04:23,479 Speaker 1: physics and weather conditions determine snowflakes shape and size, but 66 00:04:23,880 --> 00:04:28,440 Speaker 1: math determines that those flakes are unique. Consider that each 67 00:04:28,440 --> 00:04:31,800 Speaker 1: snowflake is made up of a huge number of water molecules. 68 00:04:32,120 --> 00:04:36,520 Speaker 1: By one estimate, as many as a quintillion molecules per flake. 69 00:04:37,640 --> 00:04:41,440 Speaker 1: Because each little branch of a snowflake can spawn many others, 70 00:04:41,480 --> 00:04:44,640 Speaker 1: there are dozens and dozens of ways for various crystalline 71 00:04:44,680 --> 00:04:48,440 Speaker 1: features to join. There are so many possible arrangements that 72 00:04:48,520 --> 00:04:51,679 Speaker 1: some scientists say there are twice as many possible crystal 73 00:04:51,720 --> 00:04:56,320 Speaker 1: combinations as there are atoms in the whole universe. Those 74 00:04:56,400 --> 00:04:59,080 Speaker 1: kinds of numbers are so large that we can't really 75 00:04:59,120 --> 00:05:03,039 Speaker 1: even comprehend them. But if the math holds, those numbers 76 00:05:03,080 --> 00:05:06,640 Speaker 1: mean that it is awfully unlikely that any two snowflakes 77 00:05:06,640 --> 00:05:12,080 Speaker 1: have ever been, or ever will be exactly alike. Furthermore, 78 00:05:12,200 --> 00:05:14,400 Speaker 1: there are all kinds of other factors at play in 79 00:05:14,440 --> 00:05:18,760 Speaker 1: snowflake formation. At any given instance. Even the tiniest fluctuation 80 00:05:18,760 --> 00:05:23,560 Speaker 1: and temperature and humidity alters crystal construction a miniature. Impurities 81 00:05:23,720 --> 00:05:27,359 Speaker 1: like flux of dust change the crystals too. The angles 82 00:05:27,360 --> 00:05:31,040 Speaker 1: with which water molecules collide with existing crystals matter as well, 83 00:05:31,640 --> 00:05:34,800 Speaker 1: and snowflakes smash into each other as they zoom and 84 00:05:34,880 --> 00:05:39,120 Speaker 1: swoop through the air, where their branches shatter new one's form, 85 00:05:39,160 --> 00:05:44,080 Speaker 1: adding to the uniqueness of every translucent little flake in 86 00:05:44,120 --> 00:05:47,640 Speaker 1: the swirling atmosphere miles above Earth's surface. All of these 87 00:05:47,720 --> 00:05:52,520 Speaker 1: variables ceaselessly change. Conditions that hold in one small space 88 00:05:52,640 --> 00:05:55,520 Speaker 1: are just a tiny bit different than those inches away 89 00:05:55,560 --> 00:05:59,280 Speaker 1: in any direction, and all of it transforms crystals and 90 00:05:59,320 --> 00:06:04,719 Speaker 1: their subsequent snowflakes in infinite ways, so snowflakes really are 91 00:06:04,920 --> 00:06:09,640 Speaker 1: nearly unlimited in their specialness. They're tiny and ephemeral testaments 92 00:06:09,720 --> 00:06:12,560 Speaker 1: of the strange and constant change in the world and 93 00:06:12,839 --> 00:06:20,560 Speaker 1: universe all around us. Today's episode is based on the 94 00:06:20,640 --> 00:06:23,960 Speaker 1: article is every snowflake Actually Unique? On how stuff works 95 00:06:23,960 --> 00:06:27,080 Speaker 1: dot com? Written by Nathan Chandler. Brainstuff is production by 96 00:06:27,120 --> 00:06:29,320 Speaker 1: Heart Radio in partnership with how stuff works dot Com, 97 00:06:29,400 --> 00:06:32,400 Speaker 1: and it's produced by Tyler Clang. For more podcasts for 98 00:06:32,480 --> 00:06:35,560 Speaker 1: my heart Radio, visit the heart Radio app, Apple Podcasts, 99 00:06:35,640 --> 00:06:37,479 Speaker 1: or wherever you listen to your favorite shows.