1 00:00:00,000 --> 00:00:03,360 Welcome to Cosmos in a Pod, Space, and Astronomy series, 2 00:00:03,360 --> 00:00:04,760 episode seven. 3 00:00:04,760 --> 00:00:06,800 Get ready for a deep dive into the universe's 4 00:00:06,800 --> 00:00:09,000 most spectacular light shows. 5 00:00:09,000 --> 00:00:13,400 We're talking supernovae, the explosive death of stars. 6 00:00:13,400 --> 00:00:16,120 Events so bright they can outshine entire galaxies 7 00:00:16,120 --> 00:00:17,160 for a short time. 8 00:00:17,160 --> 00:00:19,960 It's really hard to grasp the sheer power of these events. 9 00:00:19,960 --> 00:00:22,880 We're talking about a sudden release of energy. 10 00:00:22,880 --> 00:00:25,920 It just dwarfs anything we can even imagine creating 11 00:00:25,920 --> 00:00:26,480 here on Earth. 12 00:00:26,480 --> 00:00:27,240 I can only imagine. 13 00:00:27,240 --> 00:00:28,160 That's mind blowing. 14 00:00:28,160 --> 00:00:30,280 It's like one firework outshining a whole city 15 00:00:30,280 --> 00:00:30,920 at night. 16 00:00:30,920 --> 00:00:33,080 So why should we down here on Earth 17 00:00:33,080 --> 00:00:37,040 care about something so far away, something seemingly 18 00:00:37,040 --> 00:00:38,720 unrelated to our lives? 19 00:00:38,720 --> 00:00:40,840 Well, that's where it gets really fascinating. 20 00:00:40,840 --> 00:00:42,880 Supernovae, as destructive as they seem, 21 00:00:42,880 --> 00:00:44,600 they're actually responsible for creating 22 00:00:44,600 --> 00:00:47,120 the elements that make up everything around us, 23 00:00:47,120 --> 00:00:48,000 including us. 24 00:00:48,000 --> 00:00:48,520 Think about it. 25 00:00:48,520 --> 00:00:51,000 The carbon in your cells, the oxygen you breathe, even 26 00:00:51,000 --> 00:00:52,840 the iron in your blood, it was all 27 00:00:52,840 --> 00:00:55,340 forged in the heart of a star and flown out 28 00:00:55,340 --> 00:00:57,000 into the cosmos by a supernova. 29 00:00:57,000 --> 00:00:58,520 So we're all made of stardust. 30 00:00:58,520 --> 00:00:59,160 So amazing. 31 00:00:59,160 --> 00:01:03,720 So how does a star go from congly burning 32 00:01:03,720 --> 00:01:07,200 for billions of years to suddenly exploding 33 00:01:07,200 --> 00:01:08,720 with such incredible force? 34 00:01:08,720 --> 00:01:10,200 Well, it's not exactly sudden. 35 00:01:10,200 --> 00:01:13,280 There's a buildup to this cosmic grand finale. 36 00:01:13,280 --> 00:01:16,080 And the path depends on the type of supernova. 37 00:01:16,080 --> 00:01:17,480 You mentioned different types. 38 00:01:17,480 --> 00:01:18,160 Walk me through them. 39 00:01:18,160 --> 00:01:19,040 What's the first one? 40 00:01:19,040 --> 00:01:21,760 The first type, known as a type I supernova, 41 00:01:21,760 --> 00:01:24,760 it typically happens in a binary star system, 42 00:01:24,760 --> 00:01:26,960 two stars orbiting each other. 43 00:01:26,960 --> 00:01:29,760 Now, one of these stars is a white dwarf, 44 00:01:29,760 --> 00:01:32,720 basically the dense leftover core of a star that's 45 00:01:32,720 --> 00:01:34,440 already run out of fuel. 46 00:01:34,440 --> 00:01:38,000 If this white dwarf is close enough to its companion star, 47 00:01:38,000 --> 00:01:40,040 it starts pulling material off its neighbor. 48 00:01:40,040 --> 00:01:41,280 Like a cosmic vampire star. 49 00:01:41,280 --> 00:01:42,040 Exactly. 50 00:01:42,040 --> 00:01:44,800 Imagine this white dwarf slowly siphoning away 51 00:01:44,800 --> 00:01:48,120 material from its companion, growing larger and denser 52 00:01:48,120 --> 00:01:48,840 over time. 53 00:01:48,840 --> 00:01:50,840 Eventually, it reaches a critical point. 54 00:01:50,840 --> 00:01:52,300 It's called the Chandrasekhar limit. 55 00:01:52,300 --> 00:01:53,260 The Chandrasekhar limit. 56 00:01:53,260 --> 00:01:54,260 What happens at that point? 57 00:01:54,260 --> 00:01:55,840 Is that what triggers the explosion? 58 00:01:55,840 --> 00:01:56,720 Exactly. 59 00:01:56,720 --> 00:01:58,920 You can think of this limit like a tipping point. 60 00:01:58,920 --> 00:02:02,200 Once the white dwarf exceeds this mass, it becomes unstable. 61 00:02:02,200 --> 00:02:04,680 The internal pressure and temperature skyrocket, 62 00:02:04,680 --> 00:02:07,200 and it ignites a runaway nuclear reaction 63 00:02:07,200 --> 00:02:09,440 that completely obliterates the white dwarf 64 00:02:09,440 --> 00:02:11,040 in a blinding flash of light. 65 00:02:11,040 --> 00:02:13,440 So it's like a stellar pressure cooker gone haywire. 66 00:02:13,440 --> 00:02:14,520 Yeah. 67 00:02:14,520 --> 00:02:18,360 You mentioned that astronomers use these type I supernovae 68 00:02:18,360 --> 00:02:21,120 for something else, like being a cosmic measuring stick. 69 00:02:21,120 --> 00:02:22,000 You're right. 70 00:02:22,000 --> 00:02:24,720 Here's why type I supernovae are so useful. 71 00:02:24,720 --> 00:02:28,240 They all explode with nearly the same intrinsic brightness. 72 00:02:28,240 --> 00:02:30,600 Think of them like light bulbs of a known wattage. 73 00:02:30,600 --> 00:02:33,360 If you have 100 watt bulb and you see it shining dimly, 74 00:02:33,360 --> 00:02:34,840 you know it's far away. 75 00:02:34,840 --> 00:02:36,720 If it's super bright, it must be close. 76 00:02:36,720 --> 00:02:39,160 So by comparing the actual brightness of a type I 77 00:02:39,160 --> 00:02:43,120 supernova to how bright it appears from Earth, 78 00:02:43,120 --> 00:02:44,960 astronomers can calculate its distance. 79 00:02:44,960 --> 00:02:45,680 Precisely. 80 00:02:45,680 --> 00:02:47,240 They're called standard candles. 81 00:02:47,240 --> 00:02:49,400 And they've been instrumental in helping us map out 82 00:02:49,400 --> 00:02:52,120 the distances to far away galaxies, 83 00:02:52,120 --> 00:02:55,280 and even understand how fast the universe is expanding. 84 00:02:55,280 --> 00:02:56,560 That's amazing. 85 00:02:56,560 --> 00:02:59,480 A single type of exploding star can tell us so much 86 00:02:59,480 --> 00:03:01,760 about the vastness of the universe. 87 00:03:01,760 --> 00:03:05,000 So that's type I. What about the other type of supernova, 88 00:03:05,000 --> 00:03:06,880 the one that comes from massive stars? 89 00:03:06,880 --> 00:03:08,080 Ah, yes. 90 00:03:08,080 --> 00:03:09,840 Tag two supernovae. 91 00:03:09,840 --> 00:03:12,720 This is the grand finale for stars, at least eight times 92 00:03:12,720 --> 00:03:14,640 more massive than our sun. 93 00:03:14,640 --> 00:03:17,040 Their story begins with fusion, the heart 94 00:03:17,040 --> 00:03:18,560 of what makes a star shine. 95 00:03:18,560 --> 00:03:19,440 Fusion, right. 96 00:03:19,440 --> 00:03:21,160 That's where stars combine lighter elements 97 00:03:21,160 --> 00:03:23,080 into heavier ones, like building blocks. 98 00:03:23,080 --> 00:03:23,880 Exactly. 99 00:03:23,880 --> 00:03:27,320 These massive stars are like giant furnaces, 100 00:03:27,320 --> 00:03:30,520 constantly fusing hydrogen into helium in their cores. 101 00:03:30,520 --> 00:03:33,120 But eventually, they run out of hydrogen fuel. 102 00:03:33,120 --> 00:03:35,040 Then they start fusing helium into carbon, 103 00:03:35,040 --> 00:03:37,680 then carbon into oxygen, oxygen into silicon. 104 00:03:37,680 --> 00:03:39,680 It's a step-by-step process, building up 105 00:03:39,680 --> 00:03:41,120 heavier and heavier elements. 106 00:03:41,120 --> 00:03:42,080 Until they reach iron. 107 00:03:42,080 --> 00:03:43,360 You mentioned iron was significant. 108 00:03:43,360 --> 00:03:43,960 Why is that? 109 00:03:43,960 --> 00:03:45,280 Iron is the end of the line. 110 00:03:45,280 --> 00:03:48,000 It's the most stable element, meaning fusing iron 111 00:03:48,000 --> 00:03:49,920 doesn't release energy like the other elements. 112 00:03:49,920 --> 00:03:51,520 In fact, it requires energy. 113 00:03:51,520 --> 00:03:54,520 So once a massive star's core is filled with iron, 114 00:03:54,520 --> 00:03:56,160 it's basically out of fuel. 115 00:03:56,160 --> 00:03:58,400 And it can no longer support its own weight. 116 00:03:58,400 --> 00:04:00,320 Against the crushing force of gravity. 117 00:04:00,320 --> 00:04:01,280 So what happens then? 118 00:04:01,280 --> 00:04:02,920 Does the whole thing just collapse? 119 00:04:02,920 --> 00:04:03,480 It does. 120 00:04:03,480 --> 00:04:05,040 And it happens incredibly fast. 121 00:04:05,040 --> 00:04:07,040 The core collapses in on itself. 122 00:04:07,040 --> 00:04:09,800 The result is an unimaginable shockwave 123 00:04:09,800 --> 00:04:13,160 that rips through the star, blasting its outer layers 124 00:04:13,160 --> 00:04:15,120 into space with incredible force. 125 00:04:15,120 --> 00:04:16,680 And that's the supernova we see. 126 00:04:16,680 --> 00:04:17,240 That's it. 127 00:04:17,240 --> 00:04:19,160 That spectacular explosion. 128 00:04:19,160 --> 00:04:22,240 That brilliant light that can outshine an entire galaxy. 129 00:04:22,240 --> 00:04:24,080 That's the type 2 supernova. 130 00:04:24,080 --> 00:04:24,580 OK. 131 00:04:24,580 --> 00:04:27,080 So the outer layers of the star are blasting into space. 132 00:04:27,080 --> 00:04:27,580 Yeah. 133 00:04:27,580 --> 00:04:30,840 What happens to the core itself after this dramatic collapse? 134 00:04:30,840 --> 00:04:32,200 Is it just gone? 135 00:04:32,200 --> 00:04:33,360 Not necessarily. 136 00:04:33,360 --> 00:04:36,400 The fate of the core depends on the original mass of the star. 137 00:04:36,400 --> 00:04:38,720 For smaller massive stars, the core 138 00:04:38,720 --> 00:04:41,760 gets squeezed into an incredibly dense object 139 00:04:41,760 --> 00:04:42,760 called a neutron star. 140 00:04:42,760 --> 00:04:44,080 We've talked about those before. 141 00:04:44,080 --> 00:04:46,800 They're like giant atomic nuclei just a few miles across. 142 00:04:46,800 --> 00:04:49,280 But with the mass of an entire star packed 143 00:04:49,280 --> 00:04:50,440 into that tiny space. 144 00:04:50,440 --> 00:04:50,940 Right. 145 00:04:50,940 --> 00:04:51,800 Neutron stars. 146 00:04:51,800 --> 00:04:54,240 Those mind-bogglingly dense objects. 147 00:04:54,240 --> 00:04:56,120 But you said it depends on the original mass. 148 00:04:56,120 --> 00:04:59,080 What happens to the cores of the really massive stars? 149 00:04:59,080 --> 00:05:02,080 For those truly massive stars, the core's collapse 150 00:05:02,080 --> 00:05:03,680 doesn't stop at a neutron star. 151 00:05:03,680 --> 00:05:06,680 It keeps collapsing, becoming denser and denser, 152 00:05:06,680 --> 00:05:09,480 until it essentially disappears from our universe, 153 00:05:09,480 --> 00:05:11,160 forming a black hole. 154 00:05:11,160 --> 00:05:11,920 A black hole. 155 00:05:11,920 --> 00:05:17,120 So depending on its size, the star gets a dramatic exit. 156 00:05:17,120 --> 00:05:21,600 As either a super dense neutron star or a mysterious black 157 00:05:21,600 --> 00:05:22,760 hole. 158 00:05:22,760 --> 00:05:24,000 Talk about going out with a bang. 159 00:05:24,000 --> 00:05:24,720 But wait. 160 00:05:24,720 --> 00:05:26,880 I thought we were talking about how supernovae create things. 161 00:05:26,880 --> 00:05:28,440 This all sounds pretty destructive. 162 00:05:28,440 --> 00:05:28,960 You're right. 163 00:05:28,960 --> 00:05:32,240 Supernovae are incredibly powerful and destructive events. 164 00:05:32,240 --> 00:05:34,240 But they're also creators in a sense. 165 00:05:34,240 --> 00:05:35,560 Think about all those elements that 166 00:05:35,560 --> 00:05:38,040 were forged in the star's core over its lifetime. 167 00:05:38,040 --> 00:05:41,000 They get blasted out into space by the supernova. 168 00:05:41,000 --> 00:05:43,440 That material enriches the surrounding interstellar 169 00:05:43,440 --> 00:05:46,720 medium, seeding it with the building blocks for new stars, 170 00:05:46,720 --> 00:05:48,800 new planets, even life itself. 171 00:05:48,800 --> 00:05:52,200 So in a way, these supernovae were like cosmic gardeners, 172 00:05:52,200 --> 00:05:54,520 scattering the seeds for new life and new worlds. 173 00:05:54,520 --> 00:05:55,720 That's a great way to put it. 174 00:05:55,720 --> 00:05:58,360 Supernovae are essential to the cycle of cosmic evolution, 175 00:05:58,360 --> 00:06:00,520 a fundamental part of how the universe works. 176 00:06:00,520 --> 00:06:01,320 Wow. 177 00:06:01,320 --> 00:06:02,840 This is fascinating. 178 00:06:02,840 --> 00:06:05,120 Are there any specific supernovae 179 00:06:05,120 --> 00:06:08,720 that we've actually observed and learned from, like famous ones? 180 00:06:08,720 --> 00:06:09,320 Absolutely. 181 00:06:09,320 --> 00:06:11,560 There are quite a few famous supernovae. 182 00:06:11,560 --> 00:06:13,480 Take the Crab Nebula, for example, 183 00:06:13,480 --> 00:06:16,040 this stunning cloud of gas and dust. 184 00:06:16,040 --> 00:06:18,600 That formed from a supernova observed 185 00:06:18,600 --> 00:06:22,120 by Chinese and Arab astronomers way back in the year 1054. 186 00:06:22,120 --> 00:06:24,360 Wait, they saw a supernova almost 1,000 years ago. 187 00:06:24,360 --> 00:06:24,800 They did. 188 00:06:24,800 --> 00:06:27,920 It was so bright, it was visible during the daytime for weeks. 189 00:06:27,920 --> 00:06:30,600 The Crab Nebula is what's left of that explosion. 190 00:06:30,600 --> 00:06:34,400 And it's still expanding today, a beautiful and eerie reminder 191 00:06:34,400 --> 00:06:36,560 of the power of these cosmic events. 192 00:06:36,560 --> 00:06:37,320 That's incredible. 193 00:06:37,320 --> 00:06:38,880 What other supernovae have astronomers 194 00:06:38,880 --> 00:06:40,040 been able to study? 195 00:06:40,040 --> 00:06:44,600 A more recent one, SN 1987A, which happened in 1987, 196 00:06:44,600 --> 00:06:45,960 as the name suggests. 197 00:06:45,960 --> 00:06:49,520 It occurred in the Large Magellanic Cloud, a nearby galaxy 198 00:06:49,520 --> 00:06:51,160 that orbits our own Milky Way. 199 00:06:51,160 --> 00:06:54,320 So it was relatively close to us, astronomically speaking. 200 00:06:54,320 --> 00:06:54,800 Yes. 201 00:06:54,800 --> 00:06:56,440 It was the closest supernova observed 202 00:06:56,440 --> 00:06:59,280 in modern times, which allowed astronomers to study it 203 00:06:59,280 --> 00:07:00,480 in incredible detail. 204 00:07:00,480 --> 00:07:03,520 We learned a lot about the physics of supernova explosions 205 00:07:03,520 --> 00:07:06,040 and the formation of neutron stars from that event. 206 00:07:06,040 --> 00:07:07,280 I can imagine. 207 00:07:07,280 --> 00:07:09,840 But if these supernovae are so rare, 208 00:07:09,840 --> 00:07:13,240 how do astronomers even find them in the vastness of space? 209 00:07:13,240 --> 00:07:15,240 Do they just happen to look in the right direction 210 00:07:15,240 --> 00:07:16,240 at the right time? 211 00:07:16,240 --> 00:07:18,000 That would be incredibly lucky. 212 00:07:18,000 --> 00:07:19,080 No. 213 00:07:19,080 --> 00:07:22,440 We have much more sophisticated methods these days. 214 00:07:22,440 --> 00:07:25,520 Modern telescopes and dedicated sky surveys 215 00:07:25,520 --> 00:07:28,560 are key to finding these cosmic explosions, 216 00:07:28,560 --> 00:07:30,320 even in distant galaxies. 217 00:07:30,320 --> 00:07:32,360 So what kind of technology are we talking about here? 218 00:07:32,360 --> 00:07:34,720 Well, there's a Hubble Space Telescope, of course, 219 00:07:34,720 --> 00:07:37,520 which has captured some incredible images of supernova 220 00:07:37,520 --> 00:07:38,480 remnants. 221 00:07:38,480 --> 00:07:41,120 And then there are ground-based observatories, 222 00:07:41,120 --> 00:07:42,640 like the Vera Rubin Observatory. 223 00:07:42,640 --> 00:07:43,840 It'll be coming online soon. 224 00:07:43,840 --> 00:07:46,320 What's special about the Vera Rubin Observatory? 225 00:07:46,320 --> 00:07:49,360 It's designed to scan the entire sky every few nights, 226 00:07:49,360 --> 00:07:52,400 looking for any changes, including new supernovae. 227 00:07:52,400 --> 00:07:54,920 It's going to revolutionize our understanding of these events. 228 00:07:54,920 --> 00:07:55,600 That's exciting. 229 00:07:55,600 --> 00:07:57,600 So it sounds like we have these incredible tools 230 00:07:57,600 --> 00:07:58,840 for finding supernovae. 231 00:07:58,840 --> 00:08:00,720 But what about studying them? 232 00:08:00,720 --> 00:08:02,680 How do astronomers actually learn about what's 233 00:08:02,680 --> 00:08:04,320 happening in these explosions? 234 00:08:04,320 --> 00:08:06,920 It all comes down to analyzing the light. 235 00:08:06,920 --> 00:08:09,840 When a supernova explodes, it emits light 236 00:08:09,840 --> 00:08:12,440 across the entire electromagnetic spectrum, 237 00:08:12,440 --> 00:08:14,640 from radio waves to gamma rays. 238 00:08:14,640 --> 00:08:17,160 Astronomers use different types of telescopes 239 00:08:17,160 --> 00:08:20,080 to capture this light and then break it down 240 00:08:20,080 --> 00:08:22,360 into its component wavelengths. 241 00:08:22,360 --> 00:08:25,040 Like a prism splitting sunlight into a rainbow. 242 00:08:25,040 --> 00:08:26,240 Exactly. 243 00:08:26,240 --> 00:08:28,020 By studying the patterns in this light, 244 00:08:28,020 --> 00:08:30,960 we can learn about the chemical composition of the supernova, 245 00:08:30,960 --> 00:08:33,640 its temperature, its speed, even how 246 00:08:33,640 --> 00:08:35,760 the explosion itself unfolds. 247 00:08:35,760 --> 00:08:36,600 Wow. 248 00:08:36,600 --> 00:08:39,320 It's like they're piecing together a cosmic crime scene, 249 00:08:39,320 --> 00:08:40,800 using light as their clues. 250 00:08:40,800 --> 00:08:42,160 That's a great analogy. 251 00:08:42,160 --> 00:08:44,560 And with each new supernova we observe, 252 00:08:44,560 --> 00:08:47,000 we gain a deeper understanding of these events 253 00:08:47,000 --> 00:08:49,520 and their role in the evolution of the universe. 254 00:08:49,520 --> 00:08:51,000 It's truly remarkable what we can 255 00:08:51,000 --> 00:08:53,720 learn from these distant, fleeting flashes of light. 256 00:08:53,720 --> 00:08:55,640 This has been absolutely fascinating. 257 00:08:55,640 --> 00:08:57,360 So glad we're not too close to any 258 00:08:57,360 --> 00:08:58,680 of these potential supernovae. 259 00:08:58,680 --> 00:09:00,160 It sounds like it'd be a pretty rough day on Earth 260 00:09:00,160 --> 00:09:01,400 if one went off nearby. 261 00:09:01,400 --> 00:09:02,520 You're telling me. 262 00:09:02,520 --> 00:09:03,720 But don't worry. 263 00:09:03,720 --> 00:09:07,280 While supernovae are essential to the universe's evolution, 264 00:09:07,280 --> 00:09:10,040 we're at a safe distance from any potential candidates 265 00:09:10,040 --> 00:09:11,840 in our galactic neighborhood. 266 00:09:11,840 --> 00:09:15,560 So we can appreciate their beauty and power from afar. 267 00:09:15,560 --> 00:09:16,560 Glad to hear it. 268 00:09:16,560 --> 00:09:18,040 I think it's time for a quick break. 269 00:09:18,040 --> 00:09:20,840 But when we come back, we'll continue our supernova 270 00:09:20,840 --> 00:09:24,160 exploration with even more cosmic insights. 271 00:09:24,160 --> 00:09:25,200 Stay tuned. 272 00:09:25,200 --> 00:09:27,480 Welcome back to Cosmos CinePod. 273 00:09:27,480 --> 00:09:29,680 I hope you're ready for more supernova talk, 274 00:09:29,680 --> 00:09:31,400 because we've only just scratched the surface. 275 00:09:31,400 --> 00:09:32,680 I am so ready. 276 00:09:32,680 --> 00:09:35,120 You've got me totally hooked on these cosmic fireworks. 277 00:09:35,120 --> 00:09:36,480 Before the break, we were talking 278 00:09:36,480 --> 00:09:39,880 about how astronomers actually find and study supernovae. 279 00:09:39,880 --> 00:09:42,720 It's amazing what they can learn just by analyzing the light. 280 00:09:42,720 --> 00:09:44,360 But you also mentioned that supernovae 281 00:09:44,360 --> 00:09:47,240 are responsible for creating some of the heavier elements 282 00:09:47,240 --> 00:09:48,160 in the universe. 283 00:09:48,160 --> 00:09:49,320 Can you elaborate on that? 284 00:09:49,320 --> 00:09:49,880 Absolutely. 285 00:09:49,880 --> 00:09:52,360 We talked about how stars fuse lighter elements 286 00:09:52,360 --> 00:09:54,600 into heavier ones in their cores, right? 287 00:09:54,600 --> 00:09:56,520 Our sun, for example, can produce elements 288 00:09:56,520 --> 00:09:58,200 up to carbon and oxygen. 289 00:09:58,200 --> 00:10:00,080 But the really heavy elements, think 290 00:10:00,080 --> 00:10:01,840 of gold, platinum, uranium, those 291 00:10:01,840 --> 00:10:04,800 are forged in the intense heat and pressure of supernova 292 00:10:04,800 --> 00:10:05,840 explosions. 293 00:10:05,840 --> 00:10:07,560 So that gold necklace I'm wearing, 294 00:10:07,560 --> 00:10:09,560 it's actually made of supernova remnants. 295 00:10:09,560 --> 00:10:10,720 That's kind of mind blowing. 296 00:10:10,720 --> 00:10:11,560 You could say that. 297 00:10:11,560 --> 00:10:15,720 Every atom of gold on Earth and everywhere else in the universe 298 00:10:15,720 --> 00:10:19,360 was created in a supernova explosion billions of years ago. 299 00:10:19,360 --> 00:10:22,000 We literally carry pieces of stars within us. 300 00:10:22,000 --> 00:10:24,040 Wow, that's a powerful thought. 301 00:10:24,040 --> 00:10:27,040 So these supernovae are not only responsible for creating 302 00:10:27,040 --> 00:10:29,560 the elements we need for life, but also 303 00:10:29,560 --> 00:10:33,040 some of the most precious and valuable materials we have. 304 00:10:33,040 --> 00:10:36,640 They're like cosmic alchemists turning stars into gold. 305 00:10:36,640 --> 00:10:37,960 That's a great analogy. 306 00:10:37,960 --> 00:10:40,760 And it reminds us that even the most violent and destructive 307 00:10:40,760 --> 00:10:44,840 events in the universe can have creative consequences, 308 00:10:44,840 --> 00:10:46,760 shaping the world we know. 309 00:10:46,760 --> 00:10:48,120 Speaking of those violent events, 310 00:10:48,120 --> 00:10:49,240 I have a question for you. 311 00:10:49,240 --> 00:10:51,200 Earlier you said that a supernova can briefly 312 00:10:51,200 --> 00:10:52,960 outshine an entire galaxy. 313 00:10:52,960 --> 00:10:54,480 Just how bright are we talking here? 314 00:10:54,480 --> 00:10:56,080 Yeah, I'm still trying to wrap my head around that. 315 00:10:56,080 --> 00:10:59,160 It's hard to imagine something outshining billions of stars. 316 00:10:59,160 --> 00:11:01,360 Well, to put it into perspective, 317 00:11:01,360 --> 00:11:04,480 the energy released by a typical supernova 318 00:11:04,480 --> 00:11:07,160 is equivalent to the total energy output of our sun 319 00:11:07,160 --> 00:11:08,880 over its entire lifetime. 320 00:11:08,880 --> 00:11:11,080 Imagine all the energy our sun will produce 321 00:11:11,080 --> 00:11:14,560 over billions of years, released in just a few weeks or months. 322 00:11:14,560 --> 00:11:17,080 Whoa, that's an incredible amount of energy. 323 00:11:17,080 --> 00:11:19,360 No wonder they're so bright. 324 00:11:19,360 --> 00:11:21,560 But what happens after a supernova fades away? 325 00:11:21,560 --> 00:11:22,880 What's left behind? 326 00:11:22,880 --> 00:11:23,800 It depends. 327 00:11:23,800 --> 00:11:26,400 As we discussed, a type 2 supernova, 328 00:11:26,400 --> 00:11:29,640 the death of a massive star, can leave behind either a neutron 329 00:11:29,640 --> 00:11:30,840 star or a black hole. 330 00:11:30,840 --> 00:11:34,960 Right, the super dense leftovers, or a cosmic vacuum cleaner. 331 00:11:34,960 --> 00:11:38,320 What about type I supernovae, those white dwarf explosions? 332 00:11:38,320 --> 00:11:40,960 In those cases, there's often nothing left behind. 333 00:11:40,960 --> 00:11:44,000 The white dwarf is completely obliterated in the explosion, 334 00:11:44,000 --> 00:11:46,960 leaving behind only an expanding cloud of gas and dust. 335 00:11:46,960 --> 00:11:49,480 So it's like the ultimate disappearing act, poof, gone. 336 00:11:49,480 --> 00:11:50,560 You could say that. 337 00:11:50,560 --> 00:11:52,480 But even though the star itself is gone, 338 00:11:52,480 --> 00:11:54,240 the material it blasts out into space 339 00:11:54,240 --> 00:11:56,000 continues to interact with its surroundings. 340 00:11:56,000 --> 00:11:58,160 It can influence the evolution of galaxies, 341 00:11:58,160 --> 00:12:00,200 even trigger the formation of new stars. 342 00:12:00,200 --> 00:12:03,240 So even in their death, supernovae 343 00:12:03,240 --> 00:12:06,240 contribute to the ongoing cycle of creation and destruction 344 00:12:06,240 --> 00:12:07,520 in the universe. 345 00:12:07,520 --> 00:12:09,080 It's like a never ending story. 346 00:12:09,080 --> 00:12:10,200 Exactly. 347 00:12:10,200 --> 00:12:13,400 Each supernova leaves behind a unique fingerprint, 348 00:12:13,400 --> 00:12:16,360 a story written in the patterns of gas and dust, 349 00:12:16,360 --> 00:12:18,280 that we can study and learn from. 350 00:12:18,280 --> 00:12:21,520 It's like a cosmic echo of a star's life and death. 351 00:12:21,520 --> 00:12:23,520 This is all so fascinating. 352 00:12:23,520 --> 00:12:26,200 It makes you appreciate the interconnectedness of everything 353 00:12:26,200 --> 00:12:27,440 in the universe. 354 00:12:27,440 --> 00:12:29,680 But I have to admit, I still have a lot of questions 355 00:12:29,680 --> 00:12:31,040 about supernovae. 356 00:12:31,040 --> 00:12:33,760 For example, how often do they actually occur? 357 00:12:33,760 --> 00:12:36,000 I mean, are we likely to see one in our lifetime? 358 00:12:36,000 --> 00:12:38,320 Well, supernovae are relatively rare events, 359 00:12:38,320 --> 00:12:39,720 at least in our own galaxy. 360 00:12:39,720 --> 00:12:41,600 Astronomers estimate that a supernova 361 00:12:41,600 --> 00:12:45,080 occurs in the Milky Way about once every 50 to 100 years. 362 00:12:45,080 --> 00:12:46,240 So we're due for one soon? 363 00:12:46,240 --> 00:12:48,960 Well, soon is a relative term in astronomy. 364 00:12:48,960 --> 00:12:51,040 But it's certainly possible that we could witness 365 00:12:51,040 --> 00:12:52,560 a supernova in our lifetime. 366 00:12:52,560 --> 00:12:53,480 Wow. 367 00:12:53,480 --> 00:12:55,440 I can only imagine what a sight that would be. 368 00:12:55,440 --> 00:12:57,160 But you mentioned that we can observe supernovae 369 00:12:57,160 --> 00:12:58,080 in other galaxies, right? 370 00:12:58,080 --> 00:12:59,960 So even if we don't see one in our own galaxy, 371 00:12:59,960 --> 00:13:01,080 we can still study them. 372 00:13:01,080 --> 00:13:01,920 Yes. 373 00:13:01,920 --> 00:13:04,560 And thanks to modern telescopes and surveys, 374 00:13:04,560 --> 00:13:07,960 we're detecting supernovae in other galaxies all the time. 375 00:13:07,960 --> 00:13:10,160 In fact, astronomers discover thousands 376 00:13:10,160 --> 00:13:11,800 of supernovae each year. 377 00:13:11,800 --> 00:13:13,000 Thousands. 378 00:13:13,000 --> 00:13:13,840 That's incredible. 379 00:13:13,840 --> 00:13:16,160 So while they're rare in our own galaxy, 380 00:13:16,160 --> 00:13:18,800 they're actually quite common across the universe as a whole. 381 00:13:18,800 --> 00:13:19,760 Exactly. 382 00:13:19,760 --> 00:13:22,680 And by studying these distant supernovae, 383 00:13:22,680 --> 00:13:24,800 we can learn a great deal about the evolution of stars 384 00:13:24,800 --> 00:13:27,880 in galaxies and even about the fundamental properties 385 00:13:27,880 --> 00:13:29,320 of the universe itself. 386 00:13:29,320 --> 00:13:32,240 So each supernova is like a unique window 387 00:13:32,240 --> 00:13:34,840 into the distant past, offering clues 388 00:13:34,840 --> 00:13:36,760 about the history of the cosmos. 389 00:13:36,760 --> 00:13:38,280 It's almost like reading a history book written 390 00:13:38,280 --> 00:13:39,320 in starlight. 391 00:13:39,320 --> 00:13:40,600 That's a beautiful way to put it. 392 00:13:40,600 --> 00:13:42,160 They're like cosmic time capsules, 393 00:13:42,160 --> 00:13:44,440 carrying information about the conditions of the universe 394 00:13:44,440 --> 00:13:45,840 billions of years ago. 395 00:13:45,840 --> 00:13:49,040 It's amazing to think that we can access that information 396 00:13:49,040 --> 00:13:51,040 from our little planet here on Earth. 397 00:13:51,040 --> 00:13:53,120 But we've talked a lot about the scientific aspects 398 00:13:53,120 --> 00:13:54,440 of supernovae. 399 00:13:54,440 --> 00:13:56,240 What about the cultural impact? 400 00:13:56,240 --> 00:13:57,880 Have these events had any influence 401 00:13:57,880 --> 00:13:59,880 on human history or mythology? 402 00:13:59,880 --> 00:14:01,000 That's a great question. 403 00:14:01,000 --> 00:14:03,440 And the answer is definitely yes. 404 00:14:03,440 --> 00:14:05,600 Throughout history, people have been awestruck 405 00:14:05,600 --> 00:14:09,760 by the sudden appearance of bright new stars in the sky. 406 00:14:09,760 --> 00:14:13,800 Imagine seeing a new brilliant point of light appear. 407 00:14:13,800 --> 00:14:16,560 Where none was before, long before we understood 408 00:14:16,560 --> 00:14:19,480 what was happening, it must have been a truly awe-inspiring 409 00:14:19,480 --> 00:14:21,080 and perhaps even frightening sight. 410 00:14:21,080 --> 00:14:22,160 I can imagine. 411 00:14:22,160 --> 00:14:23,960 It makes sense that cultures would incorporate 412 00:14:23,960 --> 00:14:27,520 these selectual events into their myths and legends. 413 00:14:27,520 --> 00:14:28,720 Exactly, and they did. 414 00:14:28,720 --> 00:14:31,480 Many cultures incorporated supernovae into their stories. 415 00:14:31,480 --> 00:14:33,400 For example, in some ancient cultures, 416 00:14:33,400 --> 00:14:36,080 supernovae were seen as omens, portending 417 00:14:36,080 --> 00:14:37,600 either good or bad fortune. 418 00:14:37,600 --> 00:14:40,120 Oh, like celestial messengers from the gods. 419 00:14:40,120 --> 00:14:41,600 In a way, yes. 420 00:14:41,600 --> 00:14:43,280 They were seen as signs from the gods 421 00:14:43,280 --> 00:14:45,040 or as messages from the universe itself. 422 00:14:45,040 --> 00:14:47,320 It's a testament to the power of these events 423 00:14:47,320 --> 00:14:49,200 to capture the human imagination. 424 00:14:49,200 --> 00:14:51,000 It seems like supernovae have always 425 00:14:51,000 --> 00:14:54,800 had a way of making us look up and wonder about our place 426 00:14:54,800 --> 00:14:57,160 in the cosmos, even when we didn't fully 427 00:14:57,160 --> 00:14:58,240 understand what they were. 428 00:14:58,240 --> 00:15:00,640 Absolutely, and even today. 429 00:15:00,640 --> 00:15:02,200 With all our scientific knowledge, 430 00:15:02,200 --> 00:15:05,160 there's still a sense of wonder and awe 431 00:15:05,160 --> 00:15:07,520 when we witness the death of a star 432 00:15:07,520 --> 00:15:09,320 and the birth of something new in the universe. 433 00:15:09,320 --> 00:15:11,360 It really makes you think about the grand scheme of things. 434 00:15:11,360 --> 00:15:12,320 I couldn't agree more. 435 00:15:12,320 --> 00:15:15,160 There's something truly poetic about the cycle of life 436 00:15:15,160 --> 00:15:18,760 and death playing out on such a grand scale. 437 00:15:18,760 --> 00:15:21,960 It's a reminder that we are all part of something much larger 438 00:15:21,960 --> 00:15:22,720 than ourselves. 439 00:15:22,720 --> 00:15:23,800 Well said. 440 00:15:23,800 --> 00:15:27,160 And on that note, I think we've covered a lot of ground today, 441 00:15:27,160 --> 00:15:30,320 from the science of supernovae to their cultural impact. 442 00:15:30,320 --> 00:15:32,400 But before we wrap things up completely, 443 00:15:32,400 --> 00:15:36,000 we have one more exciting aspect of supernovae to explore. 444 00:15:36,000 --> 00:15:37,120 You've got my attention. 445 00:15:37,120 --> 00:15:37,920 What else is there? 446 00:15:37,920 --> 00:15:40,640 We're going to delve into how these stellar explosions can 447 00:15:40,640 --> 00:15:43,560 actually help us understand the universe on an even grander 448 00:15:43,560 --> 00:15:44,520 scale. 449 00:15:44,520 --> 00:15:46,800 We're talking about cosmology, the study 450 00:15:46,800 --> 00:15:49,560 of the origin and evolution of the universe itself. 451 00:15:49,560 --> 00:15:50,880 Oh, this sounds good. 452 00:15:50,880 --> 00:15:52,520 I'm ready to dive even deeper. 453 00:15:52,520 --> 00:15:54,560 Welcome back to Cosmos CinePod. 454 00:15:54,560 --> 00:15:57,720 We're wrapping up our deep dive into the fascinating world 455 00:15:57,720 --> 00:15:59,120 of supernovae. 456 00:15:59,120 --> 00:16:02,200 And I'm ready to hear how these stellar explosions can 457 00:16:02,200 --> 00:16:04,680 shed light on the entire universe. 458 00:16:04,680 --> 00:16:06,720 You were about to explain how supernovae connect 459 00:16:06,720 --> 00:16:08,040 to cosmology, right? 460 00:16:08,040 --> 00:16:08,760 Exactly. 461 00:16:08,760 --> 00:16:10,480 It might sound surprising. 462 00:16:10,480 --> 00:16:12,280 But these distant fleeting events 463 00:16:12,280 --> 00:16:15,040 can help us understand the universe's biggest secrets. 464 00:16:15,040 --> 00:16:17,880 Specifically, type Ia supernovae, 465 00:16:17,880 --> 00:16:20,120 those white dwarf explosions we talked about. 466 00:16:20,120 --> 00:16:23,080 They're incredibly valuable tools for cosmologists. 467 00:16:23,080 --> 00:16:26,240 OK, remind me again, why are type Ia supernovae so special? 468 00:16:26,240 --> 00:16:27,640 You said there were standard candles. 469 00:16:27,640 --> 00:16:29,920 Right, because they all explode with nearly 470 00:16:29,920 --> 00:16:31,840 the same intrinsic brightness. 471 00:16:31,840 --> 00:16:33,600 We can use them to measure distances 472 00:16:33,600 --> 00:16:35,640 across the vastness of space. 473 00:16:35,640 --> 00:16:36,640 Think about it this way. 474 00:16:36,640 --> 00:16:40,960 If you have two identical light bulbs, but one appears dimmer, 475 00:16:40,960 --> 00:16:42,280 you know it must be farther away. 476 00:16:42,280 --> 00:16:42,760 Right. 477 00:16:42,760 --> 00:16:45,200 So by knowing the actual brightness of a type Ia 478 00:16:45,200 --> 00:16:48,040 supernova and comparing it to how bright it appears to us, 479 00:16:48,040 --> 00:16:49,680 we can figure out how far away it is. 480 00:16:49,680 --> 00:16:51,160 But how does that help us understand 481 00:16:51,160 --> 00:16:52,440 the universe as a whole? 482 00:16:52,440 --> 00:16:54,800 It's all about the expansion of the universe. 483 00:16:54,800 --> 00:16:57,240 Remember, we live in an expanding universe 484 00:16:57,240 --> 00:17:00,280 where galaxies are constantly moving away from each other. 485 00:17:00,280 --> 00:17:03,740 By observing type Ia supernovae in distant galaxies, 486 00:17:03,740 --> 00:17:05,960 we can not only determine their distances, 487 00:17:05,960 --> 00:17:08,320 but also how fast they're moving away from us. 488 00:17:08,320 --> 00:17:10,520 So it's like, we have these cosmic mile 489 00:17:10,520 --> 00:17:12,680 markers scattered throughout the universe. 490 00:17:12,680 --> 00:17:15,720 And by watching how they move, we 491 00:17:15,720 --> 00:17:18,240 can trace the history of the universe's expansion. 492 00:17:18,240 --> 00:17:18,960 Exactly. 493 00:17:18,960 --> 00:17:22,200 And what's even more amazing is that these observations 494 00:17:22,200 --> 00:17:24,440 led to a groundbreaking discovery. 495 00:17:24,440 --> 00:17:26,440 The universe's expansion isn't constant. 496 00:17:26,440 --> 00:17:27,920 It's actually accelerating. 497 00:17:27,920 --> 00:17:29,200 Wait, accelerating? 498 00:17:29,200 --> 00:17:31,400 You mean the galaxies are moving away from each other 499 00:17:31,400 --> 00:17:32,880 faster and faster over time? 500 00:17:32,880 --> 00:17:33,680 That's wild. 501 00:17:33,680 --> 00:17:34,680 What's causing that? 502 00:17:34,680 --> 00:17:36,320 That's the million dollar question. 503 00:17:36,320 --> 00:17:38,260 It leads us to one of the biggest mysteries 504 00:17:38,260 --> 00:17:41,080 in modern cosmology, dark energy. 505 00:17:41,080 --> 00:17:42,320 Dark energy? 506 00:17:42,320 --> 00:17:43,280 What is that exactly? 507 00:17:43,280 --> 00:17:45,500 It's this hypothetical form of energy 508 00:17:45,500 --> 00:17:47,760 that seems to permeate all of space, 509 00:17:47,760 --> 00:17:49,760 acting like a sort of anti-gravity, 510 00:17:49,760 --> 00:17:50,960 pushing everything apart. 511 00:17:50,960 --> 00:17:53,880 We don't know exactly what it is or where it comes from. 512 00:17:53,880 --> 00:17:56,200 But it's thought to be responsible for the accelerated 513 00:17:56,200 --> 00:17:57,360 expansion of the universe. 514 00:17:57,360 --> 00:18:01,160 So it's like an invisible force counteracting gravity 515 00:18:01,160 --> 00:18:02,720 on a cosmic scale. 516 00:18:02,720 --> 00:18:03,680 That's mind-boggling. 517 00:18:03,680 --> 00:18:04,780 It really is. 518 00:18:04,780 --> 00:18:07,240 And while we still have a lot to learn about dark energy, 519 00:18:07,240 --> 00:18:10,040 its discovery wouldn't have been possible without those distant 520 00:18:10,040 --> 00:18:12,300 type Ia supernovae. 521 00:18:12,300 --> 00:18:14,600 Acting as our cosmic guides, they've 522 00:18:14,600 --> 00:18:18,560 opened up a whole new realm of exploration in cosmology. 523 00:18:18,560 --> 00:18:20,960 It's incredible how much we've learned about the universe. 524 00:18:20,960 --> 00:18:23,320 Just by studying these exploding stars, 525 00:18:23,320 --> 00:18:26,160 we've gone from understanding the elements they create 526 00:18:26,160 --> 00:18:28,680 to mapping the expansion of the universe. 527 00:18:28,680 --> 00:18:30,640 It really highlights the interconnectedness 528 00:18:30,640 --> 00:18:32,400 of everything in the cosmos, doesn't it? 529 00:18:32,400 --> 00:18:33,420 It absolutely does. 530 00:18:33,420 --> 00:18:34,800 And it underscores the importance 531 00:18:34,800 --> 00:18:37,620 of continued scientific exploration and discovery. 532 00:18:37,620 --> 00:18:40,480 Who knows what other secrets these cosmic explosions hold, 533 00:18:40,480 --> 00:18:42,280 just waiting to be uncovered. 534 00:18:42,280 --> 00:18:43,560 That's a great point. 535 00:18:43,560 --> 00:18:45,000 Well, I think that's all the time we have for today. 536 00:18:45,000 --> 00:18:47,760 Thank you so much for joining us on this cosmic journey. 537 00:18:47,760 --> 00:18:50,400 I hope you learned something new about these incredible events. 538 00:18:50,400 --> 00:18:53,160 If you enjoyed this episode, be sure to follow and subscribe 539 00:18:53,160 --> 00:18:56,140 to Cosmos in a Pod for more deep dives into the wonders 540 00:18:56,140 --> 00:18:56,880 of the universe. 541 00:18:56,880 --> 00:19:11,080 Until next time, keep looking up.