WEBVTT 1 00:00:03.399 --> 00:00:07.719 Welcome to Bedtime Astronomy. Explore the wonders of the cosmos 2 00:00:07.759 --> 00:00:12.279 with our soothing Bedtime Astronomie podcast. Each episode offers a 3 00:00:12.359 --> 00:00:16.320 gentle journey through the stars, planets, and beyond, perfect for 4 00:00:16.399 --> 00:00:20.239 unwinding after a long day. Let's travel through the mysteries 5 00:00:20.239 --> 00:00:22.440 of the universe as you drift off into a peaceful 6 00:00:22.480 --> 00:00:23.800 slumber under the night sky. 7 00:00:26.879 --> 00:00:28.879 I want you to try a little thought experiment with me. 8 00:00:29.079 --> 00:00:32.520 It's a bit of a terrifying one, but just just bear. 9 00:00:32.320 --> 00:00:33.840 With me for a second, Okay, I'm with you. 10 00:00:34.119 --> 00:00:37.240 Imagine you're standing out in a field. It's a clear night, 11 00:00:37.640 --> 00:00:40.399 the air is cold and crisp, maybe it's winter, and 12 00:00:40.439 --> 00:00:43.280 you're looking up at the constellation Oriyan the Hunter, you know, 13 00:00:43.320 --> 00:00:46.439 the one, three stars for the belt, the sword hanging down, 14 00:00:46.560 --> 00:00:51.119 and that big angry red start to shoulder Beetlegeez. 15 00:00:51.280 --> 00:00:52.560 Can't miss it, exactly. 16 00:00:52.840 --> 00:00:54.799 It's a fixture. It's been in our story since we 17 00:00:54.840 --> 00:00:58.320 started writing things down. It's a cosmic landmark, an anchor 18 00:00:58.359 --> 00:01:01.159 for humanity. Really. Now, I want you to keep your 19 00:01:01.159 --> 00:01:04.040 eyes on that red dot. Don't blink, just watch it. 20 00:01:04.760 --> 00:01:10.680 And then suddenly the light just cuts out. No explosion, 21 00:01:11.239 --> 00:01:15.519 no beautiful expanding cloud of gas, none of that supernova 22 00:01:15.519 --> 00:01:17.840 stuff that turns night into day for a few weeks. 23 00:01:17.840 --> 00:01:20.359 It's just it's there, and then it's not a hole 24 00:01:20.400 --> 00:01:22.640 in the sky, a hole in I don't know. 25 00:01:22.760 --> 00:01:25.319 In reality, it gives you a physical reaction just thinking 26 00:01:25.359 --> 00:01:27.200 about it. Yeah, it's unnerving. 27 00:01:27.439 --> 00:01:30.079 It is, isn't it. It feels fundamentally wrong. Everything we 28 00:01:30.120 --> 00:01:33.000 know about physics tells us that energy doesn't just disappear, 29 00:01:33.359 --> 00:01:36.239 you know, massive objects don't just vanish into thin air. 30 00:01:36.879 --> 00:01:39.680 If beetle Jews winked out of existence tonight, the panic 31 00:01:39.680 --> 00:01:42.480 wouldn't just be among astronomers, it would be existential. We 32 00:01:42.519 --> 00:01:45.000 feel like the universe just glitched, like a pixel in 33 00:01:45.040 --> 00:01:46.719 the simulation just went dead. 34 00:01:46.959 --> 00:01:50.319 It would absolutely challenge our very deep seated comfort with 35 00:01:50.439 --> 00:01:53.400 the permanence of the cosmos. I mean, we rely on 36 00:01:53.480 --> 00:01:57.640 the violent deaths of stars on supernovae to explain so 37 00:01:57.760 --> 00:02:01.879 much about well, about us, where the elements came from. 38 00:02:02.319 --> 00:02:05.200 But silence, silence is just is spooky. 39 00:02:05.319 --> 00:02:07.239 And yet silence is exactly what we're here to talk 40 00:02:07.239 --> 00:02:12.400 about today. Because this whole scenario, this impossible, terrifying, vanishing act, 41 00:02:13.159 --> 00:02:15.840 it's not hypothetical anymore. It actually happened. 42 00:02:15.879 --> 00:02:18.080 It did in a galaxy not so far away. 43 00:02:18.199 --> 00:02:20.479 It didn't happen to Beatlecheos, thank goodness for the sake 44 00:02:20.520 --> 00:02:22.479 of our night sky. But it happened to our next 45 00:02:22.520 --> 00:02:25.479 door neighbor. We're looking at a report that was released 46 00:02:25.840 --> 00:02:28.759 just yesterday, February twelfth, twenty twenty six. It was published 47 00:02:28.759 --> 00:02:31.919 in Science magazine with support from the Simonce Foundation, and 48 00:02:32.000 --> 00:02:35.759 it details the life and the very very sudden death 49 00:02:36.280 --> 00:02:41.159 of a star with well the distinctly unromantic name of 50 00:02:41.599 --> 00:02:44.120 M thirty one twenty fourteen DS. 51 00:02:43.719 --> 00:02:46.840 One, a name only a cataloger could love, for sure exactly. 52 00:02:47.000 --> 00:02:49.360 But you shouldn't let that barcode of a name fool you. 53 00:02:49.960 --> 00:02:52.240 This star is at the very center of a mystery 54 00:02:52.319 --> 00:02:55.360 that's been I mean, it's been nagging astrophysicists for decades. 55 00:02:55.560 --> 00:02:55.919 It is. 56 00:02:56.199 --> 00:02:59.439 We are talking about the case of the failed super nova. 57 00:02:58.919 --> 00:03:01.000 Which is a term that I think for most people 58 00:03:01.120 --> 00:03:04.759 just sounds like a complete oxy moron, a contradiction in term. 59 00:03:04.840 --> 00:03:07.560 It really does. When I hear supernova, my brain immediately 60 00:03:07.599 --> 00:03:11.120 goes to the most violent, explosive, ridiculously over the top 61 00:03:11.159 --> 00:03:14.319 event imaginable so how does one fail? Did it just 62 00:03:14.439 --> 00:03:16.759 trip over its own shoelaces on the way to the 63 00:03:16.840 --> 00:03:17.879 explosion in a. 64 00:03:17.800 --> 00:03:20.599 Way that's not a bad analogy. Kind of did, But 65 00:03:20.680 --> 00:03:24.080 the consequences of that trip are, well, they're just fascinating. 66 00:03:25.039 --> 00:03:29.039 What we're really discussing today is the clearest, most unambiguous 67 00:03:29.080 --> 00:03:33.080 observation humanity has ever made of a massive star collapsing 68 00:03:33.159 --> 00:03:36.479 directly into a black hole with no bang, no bang, 69 00:03:36.560 --> 00:03:39.800 no fireworks, just a star that got too heavy, gave 70 00:03:39.879 --> 00:03:43.159 up the ghosts, and crushed itself completely out of existence. 71 00:03:43.360 --> 00:03:46.280 So this report is essentially the autopsy of a silent death. 72 00:03:46.520 --> 00:03:49.240 And what's really incredible to me is the detective work 73 00:03:49.280 --> 00:03:52.000 involved here. I mean, we're talking about spotting a single 74 00:03:52.039 --> 00:03:56.680 star blinking out in a galaxy that contains a trillion stars, Yeah, 75 00:03:56.719 --> 00:03:58.319 located millions of light years away. 76 00:03:58.360 --> 00:04:01.080 It's the ultimate neil in a haystack. Yeah, except in 77 00:04:01.080 --> 00:04:03.560 this case, the needle suddenly decides to become invisible. 78 00:04:03.639 --> 00:04:06.599 Right, So today let's just walk through this whole investigation. 79 00:04:06.639 --> 00:04:09.719 We're gonna look at the victim, this star M thirty 80 00:04:09.719 --> 00:04:11.879 one twenty fourteen DS one. We're gonna look at the 81 00:04:11.960 --> 00:04:14.199 murder weapon, gravity, and then we have to look at 82 00:04:14.199 --> 00:04:18.040 the alibi, this new idea of stellar convection that explains 83 00:04:18.120 --> 00:04:20.920 why the star didn't just vanish instantly, but actually left 84 00:04:20.959 --> 00:04:23.519 behind this this ghostly fingerprint, and. 85 00:04:23.360 --> 00:04:26.160 That fingerprint, that a little bit of leftover glow. That's 86 00:04:26.199 --> 00:04:28.519 the key to the whole thing. It challenges a lot 87 00:04:28.519 --> 00:04:31.120 of our basic assumptions about how black holes are even born. 88 00:04:31.360 --> 00:04:33.480 Okay, so before we get into the you know, the 89 00:04:33.600 --> 00:04:36.759 nitty gritty physics at the collapse, let's just set the scene. 90 00:04:36.800 --> 00:04:39.319 We need to go to the Andromeda galaxy M. 91 00:04:39.160 --> 00:04:41.240 Thirty one, our big sister galaxy. 92 00:04:41.319 --> 00:04:44.279 Right, It's about two and a half million light years away, 93 00:04:45.040 --> 00:04:47.399 And I feel like we just gloss over that number 94 00:04:47.759 --> 00:04:51.160 way too often. When we say this star vanished in 95 00:04:51.240 --> 00:04:52.319 twenty sixteen, we. 96 00:04:52.279 --> 00:04:54.360 I mean the lights stopped arriving here in twenty. 97 00:04:54.160 --> 00:04:57.879 Sixteen, exactly. The actual event, the death of the star 98 00:04:57.959 --> 00:04:59.519 happened two and a half million years ago. 99 00:04:59.680 --> 00:05:02.079 Yeah, and Homo habilist was just sort of figuring out 100 00:05:02.120 --> 00:05:05.079 the whole stone tools thing on Earth. This star was 101 00:05:05.120 --> 00:05:09.439 already dying. We were watching a very very old cosmic rerun. 102 00:05:09.560 --> 00:05:11.879 That time delay always messes with my head okay, but 103 00:05:11.920 --> 00:05:14.439 let's talk about the star itself. M thirty one twenty 104 00:05:14.439 --> 00:05:17.240 fourteen DS one. This wasn't some minor player, was it. 105 00:05:17.240 --> 00:05:18.000 This was a big deal. 106 00:05:18.079 --> 00:05:21.079 Oh no, this was an absolute heavyweight. The paper categorizes 107 00:05:21.120 --> 00:05:24.199 it as a massive star, but more specifically, we're looking 108 00:05:24.279 --> 00:05:26.680 at something in the neighborhood of twenty solar. 109 00:05:26.399 --> 00:05:28.600 Masses twenty times the mass of our. 110 00:05:28.480 --> 00:05:33.480 Sun, twenty times, And in astrophysics, mass is destiny. There's 111 00:05:33.480 --> 00:05:34.240 no escaping it. 112 00:05:34.240 --> 00:05:34.839 It's everything. 113 00:05:34.920 --> 00:05:37.639 It is entirely destiny. A star like our Sun. It'll 114 00:05:37.639 --> 00:05:40.480 die pretty gently, it'll puff off its outer layers, it'll 115 00:05:40.519 --> 00:05:43.800 become a white dwarf. It's a quiet retirement. But when 116 00:05:43.839 --> 00:05:47.079 you get above say, eight, maybe ten times the mass 117 00:05:47.120 --> 00:05:49.959 of the Sun, you enter a totally different realm, the 118 00:05:50.000 --> 00:05:51.240 realm of violent deaths. 119 00:05:51.560 --> 00:05:53.199 These are the rock stars at the galaxy. 120 00:05:53.240 --> 00:05:55.959 They absolutely are. They live fast, they burn incredibly bright, 121 00:05:56.240 --> 00:05:58.040 and they die young and spectacular, and. 122 00:05:58.160 --> 00:06:00.439 Usually they die loud, very very loud. 123 00:06:00.600 --> 00:06:03.920 Usually, and M thirty one twenty fourteen DS one was 124 00:06:03.959 --> 00:06:07.319 one of the most luminous stars in the entire Andromeda Galaxy. 125 00:06:07.319 --> 00:06:09.639 If you were an astronomer observing M thirty one this 126 00:06:09.720 --> 00:06:12.519 star was it was basically shouting its presence at you. 127 00:06:12.519 --> 00:06:15.120 It was shining with the intensity of tens of thousands 128 00:06:15.120 --> 00:06:16.680 of our suns a real beacon. 129 00:06:16.800 --> 00:06:19.959 Okay, so it's a cosmic lighthouse, and it's twenty fourteen. 130 00:06:20.319 --> 00:06:23.199 The light from the star is hitting our telescopes. But 131 00:06:23.240 --> 00:06:25.439 it wasn't just any telescope watching it, was it. This 132 00:06:25.519 --> 00:06:27.920 is where the detective story gets really interesting. The main 133 00:06:28.000 --> 00:06:29.839 data came from a project called NEOWISE. 134 00:06:30.240 --> 00:06:33.319 Right, and Neo WISE is a fascinating instrument in and 135 00:06:33.360 --> 00:06:36.920 of itself. It's a space telescope from NASA. Originally its 136 00:06:37.000 --> 00:06:40.560 name was just WISE, the Wide Field Infrared Survey Explorer, 137 00:06:41.079 --> 00:06:43.639 and its whole job was to map the entire sky 138 00:06:43.800 --> 00:06:44.759 in infrared. 139 00:06:44.480 --> 00:06:45.920 Light, so in heat radiation. 140 00:06:46.040 --> 00:06:48.959 Basically exactly, it's seeing what our eyes can't. It's seeing 141 00:06:49.040 --> 00:06:52.040 the thermal glow of the universe. YE Now WISE ran 142 00:06:52.079 --> 00:06:54.639 out of its primary coolant years ago, which normally is 143 00:06:54.680 --> 00:06:57.879 a death sentence for an infrared telescope, but NASA very 144 00:06:57.920 --> 00:07:01.319 cleverly repurposed it realize it could still be used to 145 00:07:01.439 --> 00:07:05.480 hunt for near Earth objects, asteroids, comments that sort of thing. 146 00:07:05.560 --> 00:07:07.000 Hence the new name NEOWISE. 147 00:07:07.319 --> 00:07:09.720 So Its main job is hunting for asteroids that might 148 00:07:09.759 --> 00:07:11.360 be on a collision course with Earth. 149 00:07:11.480 --> 00:07:14.360 Primarily. Yes, it sweeps the sky over and over and 150 00:07:14.399 --> 00:07:16.839 over again, and it's looking for things that move or 151 00:07:16.839 --> 00:07:19.759 things that change brightness against the static background of stars. 152 00:07:20.199 --> 00:07:24.519 But here's the beautiful unintended consequence. Because it scans the 153 00:07:24.680 --> 00:07:29.680 entire sky repeatedly, it advertently created this massive time lapse 154 00:07:29.720 --> 00:07:33.000 movie of the universe. Wow, it wasn't specifically looking for 155 00:07:33.000 --> 00:07:35.519 a dying star in Andromeda. It just happened to be 156 00:07:35.560 --> 00:07:37.079 looking everywhere all the time. 157 00:07:37.240 --> 00:07:39.000 That's the real beauty of big data, isn't it. You 158 00:07:39.120 --> 00:07:41.639 end up catching things you weren't even fishing for. So 159 00:07:41.720 --> 00:07:44.240 this team, led by a researcher named Kishal A d 160 00:07:44.759 --> 00:07:49.040 they're digging through all this archival neowise data. What did 161 00:07:49.040 --> 00:07:50.360 they find? What's the timeline? 162 00:07:50.399 --> 00:07:52.319 So think construct what's called a light curve, which is 163 00:07:52.360 --> 00:07:55.800 really just a graph of the star's brightness over time. 164 00:07:56.360 --> 00:07:59.519 And from about twenty five to twenty thirteen, the star's 165 00:07:59.600 --> 00:08:02.839 pretty I mean, it's a massive bright object just doing 166 00:08:02.879 --> 00:08:05.560 its thing. But in twenty fourteen, its behavior. 167 00:08:05.240 --> 00:08:07.000 Starts to change, It starts to get brighter. 168 00:08:07.079 --> 00:08:09.680 It does specifically in the mid in for read bands, 169 00:08:09.720 --> 00:08:13.240 the star starts to glow more intensely. It's a definite uptick. 170 00:08:13.240 --> 00:08:15.279 You can think of it like a fever. The star 171 00:08:15.360 --> 00:08:16.920 is becoming unstable. It's sick. 172 00:08:17.160 --> 00:08:19.120 Is that unusual for a star that big? I thought 173 00:08:19.160 --> 00:08:20.759 they were kind of all little anyway. 174 00:08:20.439 --> 00:08:23.639 They are. That's a great point. Massive stars are notoriously cranky. 175 00:08:23.680 --> 00:08:26.759 They burp, they flare, they pulsate, So a little brightening 176 00:08:26.759 --> 00:08:28.839 on its own wouldn't be a huge red flag. But 177 00:08:28.920 --> 00:08:33.000 this brightening, it continued and it intensified until about twenty sixteen, 178 00:08:33.440 --> 00:08:36.600 and that is when the event happened, the vanishing act, 179 00:08:36.840 --> 00:08:40.960 the collapse. Between twenty sixteen and about twenty nineteen, the 180 00:08:41.080 --> 00:08:45.559 light from this star didn't just fade, It plummeted. I mean, 181 00:08:45.600 --> 00:08:48.279 we're talking about a drop in luminosity that is just 182 00:08:48.519 --> 00:08:52.200 catastrophic invisible light and in near and for red light, 183 00:08:52.519 --> 00:08:54.840 it effectively went to zero. It was gone. 184 00:08:54.960 --> 00:08:56.840 Okay. I want to clarify the terms here because the 185 00:08:56.879 --> 00:08:59.840 report makes a big deal about distinguishing between near and 186 00:09:00.200 --> 00:09:03.360 red and mid infrared. Why does that distinction matter so much? 187 00:09:03.480 --> 00:09:07.039 It's absolutely crucial to understanding the mystery. So near for red, 188 00:09:07.120 --> 00:09:09.480 is a wavelength that's very close to the visible red 189 00:09:09.559 --> 00:09:11.919 light our eyes can see. It's the kind of light 190 00:09:11.960 --> 00:09:13.799 that a very hot object like the surface of a 191 00:09:13.840 --> 00:09:16.720 star emits. Meat Infrared, on the other hand, is a 192 00:09:16.759 --> 00:09:21.399 much longer wavelength. It represents cooler temperatures. Think warm dust. Essentially, 193 00:09:21.519 --> 00:09:21.879 got it. 194 00:09:21.960 --> 00:09:26.039 So near infrared equals hot star. Mid infrared equals warm dust. 195 00:09:26.159 --> 00:09:29.039 That's the perfect mental shorthand. So in twenty sixteen, the 196 00:09:29.080 --> 00:09:31.600 hot star signal that's the visible light in the nearer infrared, 197 00:09:31.759 --> 00:09:34.720 it just switches off. It drops by a factor of ten. 198 00:09:34.600 --> 00:09:37.399 Thousand, ten thousand. That's not dimming, that's just it's gone. 199 00:09:37.840 --> 00:09:40.200 It went from being a stadium flood light to a 200 00:09:40.240 --> 00:09:43.840 single candle flame in the middle of a hurricane. By 201 00:09:43.879 --> 00:09:47.759 twenty twenty two, twenty twenty three, for all intents and purposes, 202 00:09:48.360 --> 00:09:49.679 the star was no more. 203 00:09:50.200 --> 00:09:52.120 You know, if I were an astronomer looking at that 204 00:09:52.240 --> 00:09:55.080 data for the first time, my first thought wouldn't be, oh, 205 00:09:55.120 --> 00:09:57.519 a black hole formed. My first thought would be did 206 00:09:57.559 --> 00:09:59.000 my telescope break. 207 00:09:59.320 --> 00:10:01.919 Or did satellite fly in front of the lens right? 208 00:10:02.240 --> 00:10:05.200 Or did a big cloud of space dust just drift 209 00:10:05.240 --> 00:10:05.919 in front of it? 210 00:10:06.080 --> 00:10:08.519 And the team had to rule out every single one 211 00:10:08.519 --> 00:10:12.600 of those possibilities. They checked for instrumental errors. They checked 212 00:10:12.600 --> 00:10:15.639 for what they call dust obscuration fins, where maybe the 213 00:10:15.679 --> 00:10:17.440 star just had a mass of boop and threw out 214 00:10:17.440 --> 00:10:19.600 a cloud a soot that temporarily hid it from view. 215 00:10:19.679 --> 00:10:20.879 But those would look different. 216 00:10:21.000 --> 00:10:23.480 They look very different. Doff clouds tend to dim the 217 00:10:23.519 --> 00:10:25.399 star in a particular way. They red in the light. 218 00:10:25.480 --> 00:10:28.480 They don't typically make the star disappear completely, and so 219 00:10:28.480 --> 00:10:31.240 so quickly this was different. This looked terminal. 220 00:10:31.360 --> 00:10:34.080 So to recap the timeline, we have a star that 221 00:10:34.080 --> 00:10:36.879 gets a fever. It brightens up in twenty fourteen, then 222 00:10:36.919 --> 00:10:40.240 in twenty sixteen it pulls the plug. By twenty twenty three, 223 00:10:40.279 --> 00:10:44.200 there's almost nothing left of it except this faint, ghostly 224 00:10:44.320 --> 00:10:48.000 glow in the mid infrared, the warm dust signal. 225 00:10:47.720 --> 00:10:50.679 Which tells us that something is still there. Yeah, but 226 00:10:50.759 --> 00:10:52.519 whatever it is, it's not a star anymore. 227 00:10:52.600 --> 00:10:55.639 Okay, So we have the body, well the lack of 228 00:10:55.679 --> 00:10:58.679 a body, the crime scene. But to really understand why 229 00:10:58.720 --> 00:11:00.840 this is such a big deal, why this got published 230 00:11:00.879 --> 00:11:03.759 in a major journal like Science, we have to talk 231 00:11:03.799 --> 00:11:06.519 about how a star of twenty solar mass is supposed 232 00:11:06.559 --> 00:11:09.840 to die because going out quietly is not usually on 233 00:11:09.919 --> 00:11:10.320 the menu. 234 00:11:10.440 --> 00:11:12.840 No, not at all. If you pick up any standard 235 00:11:12.879 --> 00:11:15.399 astrophysics textbook, you flip to the chapter on twenty solar 236 00:11:15.399 --> 00:11:17.559 mass stars, and that chapter ends with one word in 237 00:11:17.600 --> 00:11:19.399 big bold letters, supernova. 238 00:11:19.519 --> 00:11:21.600 Let's break down that mechanism, because I think most people 239 00:11:21.600 --> 00:11:23.799 have the general idea of star runs out of fuel, 240 00:11:23.840 --> 00:11:26.360 goes boom, but the actual mechanics of why it goes boom, 241 00:11:26.360 --> 00:11:27.519 that's the part that failed. 242 00:11:27.279 --> 00:11:29.639 Here, right, That's exactly where it feeled. So a star 243 00:11:30.759 --> 00:11:36.720 is this beautiful, delicate balancing act. We call it hydrostatic equilibrium. 244 00:11:37.120 --> 00:11:41.039 On one side, you have the relentless crushing force of gravity. 245 00:11:41.080 --> 00:11:44.440 It's pulling every single particle inward. It wants to crush 246 00:11:44.440 --> 00:11:47.519 the star into an infinitesimly small point. And on the 247 00:11:47.559 --> 00:11:49.279 other side, on the other side, you have the fusion 248 00:11:49.360 --> 00:11:53.320 engine in the core, the nuclear fire. It's generating a 249 00:11:53.360 --> 00:11:56.799 tremendous amount of outward pressure radiation pressure that holds up 250 00:11:56.840 --> 00:11:59.440 the ceiling. It's constantly pushing everything out, so it's like. 251 00:11:59.440 --> 00:12:02.279 A permanently inflated balloon, but the air inside is a 252 00:12:02.320 --> 00:12:04.320 continuous nuclear explosion. 253 00:12:03.919 --> 00:12:06.720 Precisely for millions of years. Those two forces are in 254 00:12:06.759 --> 00:12:09.799 a perfect tug of war. They're balanced. Now, massive stars 255 00:12:09.840 --> 00:12:13.279 are like they're like onions. In the core, they burn 256 00:12:13.399 --> 00:12:16.159 hydrogen to helium. When that runs out, the core shrinks 257 00:12:16.159 --> 00:12:18.559 and heats up and starts burning helium into carbon, then 258 00:12:18.600 --> 00:12:22.360 carbon into neon, neon into oxygen, oxygen into silicon. You 259 00:12:22.480 --> 00:12:25.919 get these layers upon layers of heavier and heavier element 260 00:12:26.039 --> 00:12:29.600 until you get to iron, until you hit the iron catastrophe. 261 00:12:29.759 --> 00:12:31.879 Iron is the end of the line. It's nuclear ash. 262 00:12:32.399 --> 00:12:35.360 You cannot fuse iron atoms together and get energy out 263 00:12:35.399 --> 00:12:38.480 of the process. In fact, it actually costs energy to 264 00:12:38.519 --> 00:12:41.000 fuse them. So the moment the core of the star 265 00:12:41.080 --> 00:12:45.039 turns to iron, the engine stops, the fusion furnace just 266 00:12:45.759 --> 00:12:46.399 turns off. 267 00:12:46.519 --> 00:12:47.919 The outward pressure vanishes. 268 00:12:48.039 --> 00:12:50.679 Instantly, the tug of war is over, and gravity wins, 269 00:12:50.679 --> 00:12:53.759 and it wins catastrophically. The core, which is about the 270 00:12:53.799 --> 00:12:55.639 size of the Earth but contains the mass of more 271 00:12:55.679 --> 00:12:58.480 than our Sun, collapses into something the size of a 272 00:12:58.519 --> 00:13:02.679 city action of a second. This is the core collapse. 273 00:13:02.799 --> 00:13:04.679 And this is where the neutrinos come in, right, Because 274 00:13:04.679 --> 00:13:07.120 I've read that the neutrinos are actually the real drivers 275 00:13:07.120 --> 00:13:09.039 of the explosion, not the collapse itself. 276 00:13:09.120 --> 00:13:12.320 They absolutely are. Yeah, they're the secret ingredient. When that 277 00:13:12.399 --> 00:13:15.159 core crushes down from a white dwarf density to a 278 00:13:15.200 --> 00:13:20.519 neutron star density, it releases an almost unimaginable flood of neutrinos. 279 00:13:20.600 --> 00:13:23.080 These are the little ghost particles that pass through everything. 280 00:13:23.279 --> 00:13:26.600 Normally, yes, a neutrino from the Sun can pass through 281 00:13:26.679 --> 00:13:30.279 light years of lead without interacting. But the density in 282 00:13:30.320 --> 00:13:33.600 this collapsing core is so beyond anything we can comprehend 283 00:13:34.240 --> 00:13:36.960 that even the neutrinos get trapped for just a moment, 284 00:13:37.720 --> 00:13:40.360 and in that moment they dump a massive amount of 285 00:13:40.399 --> 00:13:42.759 their energy into the layers of gas that are still 286 00:13:42.799 --> 00:13:43.480 falling inward. 287 00:13:43.759 --> 00:13:46.559 So the core collapses, it kind of bounces, it releases 288 00:13:46.639 --> 00:13:49.679 this wave of neutrinos, and that neutrino energy is what 289 00:13:49.759 --> 00:13:52.240 creates the shockwave that blows the rest of the star 290 00:13:52.360 --> 00:13:53.080 to Smotherenes. 291 00:13:53.600 --> 00:13:57.480 That is the successful supernova mechanism. That's the script. The 292 00:13:57.519 --> 00:14:00.799 shockwave rips through the star's outer layers, it energizes them. 293 00:14:00.840 --> 00:14:03.080 We see a brilliant flash of light that can outshine 294 00:14:03.120 --> 00:14:06.200 its entire galaxy and we get a beautiful expanding nebula 295 00:14:06.320 --> 00:14:06.840 left behind. 296 00:14:07.159 --> 00:14:10.600 But thirty one twenty fourteen DS one, it didn't do that. 297 00:14:10.840 --> 00:14:13.200 The shockwave apparently didn't make it out of the locker room. 298 00:14:13.559 --> 00:14:15.960 This is the heart of the failed supernova scenario. Yeah, 299 00:14:16.039 --> 00:14:18.120 imagine that shockwave is starting to move outward. It's got 300 00:14:18.120 --> 00:14:19.799 all this energy is trying to push its way out, 301 00:14:19.879 --> 00:14:22.559 but it's pushing against twenty sons worth of heavy gas 302 00:14:22.799 --> 00:14:25.720 that is falling inward at thousands of kilometers per second. 303 00:14:25.879 --> 00:14:27.840 It's like trying to stop a freight train with a 304 00:14:27.919 --> 00:14:28.519 leaf blower. 305 00:14:28.720 --> 00:14:32.960 That is a perfect analogy. The shockwave stalls. The ram 306 00:14:32.960 --> 00:14:35.759 pressure as we call it, of the infalling matter is 307 00:14:36.240 --> 00:14:39.519 just two immens. The shockwave creates a bit of a fizzle, 308 00:14:39.919 --> 00:14:42.440 maybe bubbles for a little bit, but ultimately it just 309 00:14:42.440 --> 00:14:45.000 gets overwhelmed. Gravity crushes it back down. 310 00:14:45.240 --> 00:14:49.039 So the explosion is it's suffocated before it's even born. 311 00:14:49.279 --> 00:14:51.679 Exactly. It's an engine that stalls on the launch pad, 312 00:14:52.080 --> 00:14:54.120 and all that material that was supposed to be ejected 313 00:14:54.120 --> 00:14:57.440 into space to form a nebula, it just keeps falling. 314 00:14:57.519 --> 00:15:00.399 It falls back onto the newly formed neutrons star in 315 00:15:00.440 --> 00:15:03.440 the center and that's too much mass, way too much mass. Yeah, 316 00:15:03.480 --> 00:15:07.240 the neutron star crosses its stability limit it's called the 317 00:15:07.279 --> 00:15:09.879 Tolmann Oppenheimer volkof limit if you want to get technical, 318 00:15:10.080 --> 00:15:12.399 and it can no longer support itself against its own gravity. 319 00:15:12.440 --> 00:15:15.279 It collapses further a black hole. The event horizon forms, 320 00:15:15.759 --> 00:15:17.279 the star swallows itself whole. 321 00:15:17.440 --> 00:15:20.879 Wow, that is that's a grim way to go. It's 322 00:15:20.919 --> 00:15:22.600 a cosmic suffocation. 323 00:15:22.399 --> 00:15:24.799 It really is. And for a very long time this 324 00:15:24.919 --> 00:15:26.600 was just a theory. It was something we saw in 325 00:15:26.639 --> 00:15:30.120 computer simulations. The math would sometimes say, hey, for a 326 00:15:30.159 --> 00:15:33.200 star of this particular mass and this rotation rate, the 327 00:15:33.200 --> 00:15:36.480 shockwave shouldn't make it out, But we had never definitively 328 00:15:36.519 --> 00:15:37.200 seen it happen. 329 00:15:37.320 --> 00:15:39.240 We see the black holes that are leftover, and we 330 00:15:39.240 --> 00:15:43.480 see the supernovae, but capturing the moment of transition. 331 00:15:43.120 --> 00:15:45.200 That's the holy grail of this field and. 332 00:15:45.879 --> 00:15:49.279 One fourteen DS one is that holy grail. It's the 333 00:15:49.279 --> 00:15:52.039 missing link. It's the footage of the crime as it happened. 334 00:15:52.279 --> 00:15:56.039 It connects the dots. It proves observationally that you do 335 00:15:56.080 --> 00:16:00.279 not need a spectacular visible explosion to create a dollar 336 00:16:00.360 --> 00:16:01.159 mass black hole. 337 00:16:01.240 --> 00:16:03.000 But Hold on a second. This brings us to the 338 00:16:03.000 --> 00:16:04.679 twist in the plot. And this is the part of 339 00:16:04.720 --> 00:16:08.159 the Simons Foundation report that really gets into the new physics. 340 00:16:07.720 --> 00:16:09.440 Right, the problem of the lingering light. 341 00:16:09.759 --> 00:16:13.360 Yes, if the star just collapsed directly into a black hole, 342 00:16:14.120 --> 00:16:17.480 if the shockwave failed, why did we see anything at all? 343 00:16:17.519 --> 00:16:20.799 Why did it brighten back in twenty fourteen? And more importantly, 344 00:16:20.960 --> 00:16:23.600 why is there still an infrared glow there right now? 345 00:16:23.960 --> 00:16:26.679 If it's a black hole, shouldn't it just be dark? 346 00:16:26.960 --> 00:16:29.360 It's a fantastic question. That's the one that stumped people 347 00:16:29.360 --> 00:16:33.879 for a while. If the collapse were perfectly spherical, if 348 00:16:33.919 --> 00:16:37.559 the star were just a perfectly still, non rotating ball 349 00:16:37.600 --> 00:16:41.200 of gas, it would have just blinked out, gone in milliseconds, 350 00:16:41.919 --> 00:16:46.679 end of story. But stars aren't motionless. They spin, They spin, 351 00:16:46.759 --> 00:16:49.320 and they churn. The report puts a huge emphasis on 352 00:16:49.360 --> 00:16:50.240 the roll of convection. 353 00:16:50.720 --> 00:16:53.480 Okay, so let's unpack convection in this context. I know 354 00:16:53.559 --> 00:16:55.879 convection from you know, boiling a pot of water on 355 00:16:55.879 --> 00:16:58.320 the stove. Hot stuff rises, cool stuff sinks, it creates 356 00:16:58.360 --> 00:16:58.720 a current. 357 00:16:58.799 --> 00:17:02.559 It's the exact same principle, just on a nuclear egalactic scale. 358 00:17:02.639 --> 00:17:05.640 The eider. Layers of a massive star like this a 359 00:17:05.680 --> 00:17:10.079 red supergin, are very loosely bound. They're boiling violently. You 360 00:17:10.160 --> 00:17:12.680 have these giant cells of hot plasma, some of them 361 00:17:12.759 --> 00:17:15.319 larger than our entire sun, that arise into the surface, 362 00:17:15.359 --> 00:17:17.079 cooling and then sinking back down. 363 00:17:17.119 --> 00:17:17.759 That's incredible. 364 00:17:17.839 --> 00:17:21.000 It's a chaotic, turbulent environment. But crucially, all of that 365 00:17:21.119 --> 00:17:24.240 churning motion preserves angular momentum. 366 00:17:24.279 --> 00:17:26.079 This is high school physics coming back to haunt me. 367 00:17:26.400 --> 00:17:27.480 Angular momentum. 368 00:17:28.200 --> 00:17:31.200 That's the ice skater analogy, right, That is the classic 369 00:17:31.480 --> 00:17:35.160 perfect analogy. An ice skater is spinning with her arms 370 00:17:35.200 --> 00:17:38.039 stretched out. She pulls her arms in close to her body, 371 00:17:38.240 --> 00:17:39.000 and what happens. 372 00:17:39.079 --> 00:17:40.319 She spins way faster. 373 00:17:40.559 --> 00:17:44.200 She spins much much faster. That's the conservation of angular momentum. 374 00:17:44.200 --> 00:17:47.119 You can't just create or destroy that spin. It has 375 00:17:47.160 --> 00:17:47.920 to go somewhere. 376 00:17:48.039 --> 00:17:48.359 Okay. 377 00:17:48.599 --> 00:17:52.079 Now apply that exact same principle to the collapsing star. 378 00:17:52.920 --> 00:17:54.920 You have all this churning gas way out in the 379 00:17:54.920 --> 00:17:58.240 star's envelope. As gravity starts to pull it inward toward 380 00:17:58.319 --> 00:18:01.240 the newly formed black hole, It's like a skater pulling 381 00:18:01.240 --> 00:18:04.799 our arms in. That gas starts to spin incredibly fast. 382 00:18:04.839 --> 00:18:06.039 It speeds up as it falls. 383 00:18:06.079 --> 00:18:08.680 It speeds up so much that it eventually hits what 384 00:18:08.720 --> 00:18:11.720 we call a centrifical barrier. It's just spinning too fast. 385 00:18:12.079 --> 00:18:15.000 The centrifical force pushing outwards starts to fight against the 386 00:18:15.039 --> 00:18:17.839 gravity pulling inward, so the gas can't fall straight into 387 00:18:17.839 --> 00:18:18.440 the black hole. 388 00:18:18.559 --> 00:18:20.839 It gets backed up like a traffic jam. 389 00:18:20.960 --> 00:18:23.519 It forms an accretion disc, it goes into orbit. And 390 00:18:23.559 --> 00:18:25.559 this is where the report uses an analogy that I 391 00:18:25.559 --> 00:18:27.839 think is just brilliant. It comes from one of the researchers, 392 00:18:27.839 --> 00:18:30.599 Andrea and Tony at the Flat Iron Institute. 393 00:18:30.160 --> 00:18:31.440 The bathtub analogy. 394 00:18:31.799 --> 00:18:35.519 The bathtub imagine a tub full of water. If the 395 00:18:35.559 --> 00:18:38.240 water's perfectly still and you pull the plug, what happens? 396 00:18:38.319 --> 00:18:41.279 It just glugs straight down. It drains pretty quickly. 397 00:18:41.440 --> 00:18:44.000 Right, that's a direct collapse without any rotation. 398 00:18:44.279 --> 00:18:44.759 Yeah. 399 00:18:44.799 --> 00:18:47.599 But if you get your hand in there and swirl 400 00:18:47.599 --> 00:18:51.079 the water first, give it some angular momentum, and then you. 401 00:18:50.960 --> 00:18:54.279