1 00:00:02,040 --> 00:00:07,120 Speaker 1: Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff, 2 00:00:07,160 --> 00:00:10,039 Speaker 1: Lauren Vogel bomb Here. Our Sun may look like an 3 00:00:10,039 --> 00:00:13,880 Speaker 1: eternal miasma of incandescent plasma, but one day it will die. 4 00:00:14,480 --> 00:00:17,400 Speaker 1: This may sound like a bummer, especially for anything that's 5 00:00:17,440 --> 00:00:19,599 Speaker 1: living on Earth in a few billion years, but there 6 00:00:19,680 --> 00:00:22,680 Speaker 1: is a bright side to the solar doom. According to 7 00:00:22,760 --> 00:00:25,560 Speaker 1: research published in the journal Nature, this very month, our 8 00:00:25,640 --> 00:00:29,400 Speaker 1: dead star will leave behind a shimmering legacy. It'll turn 9 00:00:29,560 --> 00:00:34,159 Speaker 1: into a massive crystal. Before we start talking about supersized 10 00:00:34,159 --> 00:00:37,400 Speaker 1: stellar crystals, we first need to understand how stars like 11 00:00:37,479 --> 00:00:40,960 Speaker 1: our Sun live and die. The Sun is fueled by 12 00:00:41,080 --> 00:00:45,760 Speaker 1: nuclear fusion. It's massive gravity crushes hydrogen atoms together in 13 00:00:45,800 --> 00:00:48,920 Speaker 1: its core to create helium, and the vast quantities of 14 00:00:49,040 --> 00:00:53,040 Speaker 1: energy released by these fusion processes push outward, maintaining a 15 00:00:53,040 --> 00:00:56,800 Speaker 1: happy equilibrium. So long as there's plenty of hydrogen fuel 16 00:00:56,920 --> 00:01:00,000 Speaker 1: feeding this process, the core remains about the same side 17 00:01:00,000 --> 00:01:03,640 Speaker 1: as in temperature around fifteen million kelvin, producing energy that 18 00:01:03,760 --> 00:01:07,319 Speaker 1: radiates throughout the Solar system, ultimately nurturing the evolution of 19 00:01:07,360 --> 00:01:11,440 Speaker 1: life on a certain habitable planet. This hydrogen burning phase 20 00:01:11,480 --> 00:01:14,399 Speaker 1: of a star's life will last of the lifetime of 21 00:01:14,400 --> 00:01:16,920 Speaker 1: our Sun. The period of stellar life is known as 22 00:01:16,959 --> 00:01:20,959 Speaker 1: the main sequence. We're currently about four point five billion 23 00:01:21,040 --> 00:01:24,760 Speaker 1: years into our Sun's main sequence days, or approximately halfway 24 00:01:24,760 --> 00:01:28,440 Speaker 1: through its life. So what happens when that hydrogen is 25 00:01:28,480 --> 00:01:31,640 Speaker 1: all used up? Things start to get a little wild, 26 00:01:31,720 --> 00:01:34,840 Speaker 1: to put it mildly. Without the outward pressure of the 27 00:01:34,920 --> 00:01:38,800 Speaker 1: energy created by fusing hydrogen, the Sun's gravity overwhelms the core, 28 00:01:39,160 --> 00:01:42,880 Speaker 1: crushing it into a smaller space and boosting its temperature tenfold. 29 00:01:43,400 --> 00:01:46,440 Speaker 1: That's okay, though, the heavier helium nuclei will begin to 30 00:01:46,480 --> 00:01:51,520 Speaker 1: fuse together, creating the outward pressure once again to maintain equilibrium. 31 00:01:51,560 --> 00:01:53,840 Speaker 1: It's predicted that this will start happening in about five 32 00:01:53,920 --> 00:01:57,240 Speaker 1: billion years, marked with a sudden outbrush of energy known 33 00:01:57,280 --> 00:02:00,640 Speaker 1: as a helium flash. As the helium fuses, carbon and 34 00:02:00,680 --> 00:02:03,640 Speaker 1: oxygen are formed and the temperature of the core rises 35 00:02:03,800 --> 00:02:08,360 Speaker 1: yet again. Soon after, even heavier elements also begin to fuse, 36 00:02:08,760 --> 00:02:10,920 Speaker 1: and the Sun on the whole will start looking a 37 00:02:10,960 --> 00:02:13,400 Speaker 1: bit worse for the wear. It will begin to swell, 38 00:02:13,680 --> 00:02:17,000 Speaker 1: blasting into planetary space with savage solar winds that will 39 00:02:17,160 --> 00:02:20,480 Speaker 1: begin to strip away its upper layers. Though our Sun 40 00:02:20,600 --> 00:02:23,519 Speaker 1: isn't massive enough to explode as a supernova, it will 41 00:02:23,520 --> 00:02:27,320 Speaker 1: turn into a red giant star, possibly expanding beyond the 42 00:02:27,440 --> 00:02:31,640 Speaker 1: orbit of Earth. Our planet will be toast. After the 43 00:02:31,720 --> 00:02:34,640 Speaker 1: death of our star, it will leave behind whispy remains 44 00:02:34,680 --> 00:02:38,640 Speaker 1: of solar plasma, creating a beautiful planetary nebula, enriched with 45 00:02:38,720 --> 00:02:41,400 Speaker 1: newly formed heavy elements that will go on to create 46 00:02:41,440 --> 00:02:44,160 Speaker 1: the next generation of stars and planets, And in its 47 00:02:44,160 --> 00:02:46,480 Speaker 1: core will be a hot stellar remnant known as a 48 00:02:46,520 --> 00:02:50,600 Speaker 1: white dwarf, a tiny dense star shimmering brightly, a testament 49 00:02:50,639 --> 00:02:52,400 Speaker 1: to the Sun that used to be in its place. 50 00:02:53,880 --> 00:02:56,720 Speaker 1: White dwarfs can sustain themselves for billions of years before 51 00:02:56,919 --> 00:03:00,160 Speaker 1: fizzing out in dimming forever. But this isn't the end 52 00:03:00,160 --> 00:03:04,120 Speaker 1: of the story. Using observations by the European GUIA mission, 53 00:03:04,280 --> 00:03:07,519 Speaker 1: which is currently making precision measurements of stars throughout our galaxy, 54 00:03:07,960 --> 00:03:10,760 Speaker 1: researchers at the University of Warwick in the UK have 55 00:03:10,880 --> 00:03:13,600 Speaker 1: stumbled on a white dwarf secret that has remained hidden 56 00:03:14,200 --> 00:03:19,360 Speaker 1: until now. Soon after forming, white dwarfs are extremely hot, 57 00:03:19,800 --> 00:03:22,280 Speaker 1: radiating the intense energy that was once held in the 58 00:03:22,320 --> 00:03:25,280 Speaker 1: core of the main sequence star that came before them. 59 00:03:25,320 --> 00:03:28,959 Speaker 1: Over billions of years. After forming, white dwarves slowly cool 60 00:03:29,280 --> 00:03:31,960 Speaker 1: and at a certain point the oxygen and carbon they 61 00:03:31,960 --> 00:03:35,440 Speaker 1: contain will go through a phase transition akin to liquid 62 00:03:35,440 --> 00:03:38,440 Speaker 1: water freezing and turning into solid ice, only at much 63 00:03:38,480 --> 00:03:42,080 Speaker 1: more extreme temperatures and pressures, and they'll solidify to form 64 00:03:42,280 --> 00:03:46,520 Speaker 1: a huge crystal. Pierre Emmanuel Tremblay, from the University of 65 00:03:46,520 --> 00:03:49,320 Speaker 1: Warwick's Department of Physics and leader of the study, said 66 00:03:49,320 --> 00:03:52,480 Speaker 1: in a press release. All white dwarves will crystallize at 67 00:03:52,520 --> 00:03:55,560 Speaker 1: some point in their evolution, although more massive white dwarfs 68 00:03:55,560 --> 00:03:58,560 Speaker 1: go through the process sooner. This means that billions of 69 00:03:58,560 --> 00:04:01,640 Speaker 1: white dwarfs in our galaxy have already completed the process 70 00:04:01,680 --> 00:04:04,880 Speaker 1: and are essentially crystal spheres in the sky. The sum 71 00:04:04,960 --> 00:04:07,360 Speaker 1: itself will become a crystal white dwarf in about ten 72 00:04:07,520 --> 00:04:13,040 Speaker 1: billion years. Tremblay's team analyzed the Gaia observations to measure 73 00:04:13,040 --> 00:04:16,479 Speaker 1: the luminosities and colors of fifteen thousand white dwarves within 74 00:04:16,560 --> 00:04:19,320 Speaker 1: three d light years of Earth. What they found was 75 00:04:19,360 --> 00:04:22,520 Speaker 1: an excess in the population of stars of specific colors 76 00:04:22,520 --> 00:04:25,960 Speaker 1: and brightness. They realized that this group of stars represented 77 00:04:26,000 --> 00:04:29,560 Speaker 1: a similar phase instellar evolution where the conditions are right 78 00:04:29,640 --> 00:04:33,200 Speaker 1: for this phase transition to occur, causing a delay in cooling, 79 00:04:33,360 --> 00:04:37,320 Speaker 1: thus slowing down the aging process. The researchers found that 80 00:04:37,360 --> 00:04:39,560 Speaker 1: some of these stars had extended their lifespan by up 81 00:04:39,560 --> 00:04:43,920 Speaker 1: to two billion years. Tremblay said in the statement, this 82 00:04:44,000 --> 00:04:47,000 Speaker 1: is the first direct evidence that white dwarfs crystallize or 83 00:04:47,080 --> 00:04:50,200 Speaker 1: transition from liquid to solid. It was predicted fifty years 84 00:04:50,200 --> 00:04:52,120 Speaker 1: ago that we should observe a pile up in the 85 00:04:52,200 --> 00:04:55,159 Speaker 1: number of white dwarves at certain luminosities and colors due 86 00:04:55,160 --> 00:05:00,440 Speaker 1: to crystallization, and only now has this been observed. Stalized 87 00:05:00,440 --> 00:05:03,760 Speaker 1: white dwarfs aren't just a stellar curiosity. Their quantum makeup 88 00:05:03,800 --> 00:05:06,920 Speaker 1: is unlike anything we can recreate in the laboratory. As 89 00:05:06,960 --> 00:05:10,719 Speaker 1: the white star material crystallizes, its material becomes ordered on 90 00:05:10,760 --> 00:05:14,440 Speaker 1: a quantum level nuclei aligning themselves in a complex lattice 91 00:05:14,560 --> 00:05:17,640 Speaker 1: with a metallic oxygen core and an outer layer enriched 92 00:05:17,680 --> 00:05:21,800 Speaker 1: with carbon. So it turns out that after stars like 93 00:05:21,839 --> 00:05:25,120 Speaker 1: our sun die, their stories aren't over all. White dwarfs 94 00:05:25,160 --> 00:05:28,520 Speaker 1: will go through this crystallization process, littering the galaxy with 95 00:05:28,640 --> 00:05:37,320 Speaker 1: massive diamond like stellar remnants. Today's episode was written by 96 00:05:37,320 --> 00:05:39,919 Speaker 1: Ian O'Neil and produced by Tyler Claying for iHeart Media 97 00:05:39,960 --> 00:05:42,080 Speaker 1: and How Stuff Works. For more on this and lots 98 00:05:42,120 --> 00:05:44,719 Speaker 1: of other shining topics, visit our home planet, how stuff 99 00:05:44,720 --> 00:05:56,760 Speaker 1: Works dot com