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 00:00:26.960 --> 00:00:30.320 Picture this it is. It's September twenty twenty three. 8 00:00:30.600 --> 00:00:30.800 Right. 9 00:00:31.079 --> 00:00:34.320 You are just going about your normal day, maybe pouring 10 00:00:34.359 --> 00:00:37.880 a cup of coffee, sitting in traffic, just taking. 11 00:00:37.600 --> 00:00:40.399 A breath, a completely ordinary Tuesday, exactly. 12 00:00:40.679 --> 00:00:43.880 But right at that exact moment, high above our heads, 13 00:00:44.240 --> 00:00:48.039 NASA's Fermi satellite registers an event in the cosmos so 14 00:00:48.280 --> 00:00:52.200 staggeringly powerful that, for a brief, just a fleeting fraction 15 00:00:52.280 --> 00:00:56.679 of a second, a single explosion outshines entire galaxies. 16 00:00:56.960 --> 00:00:58.920 It's almost hard to wrap your head around the scale 17 00:00:58.920 --> 00:00:59.200 of it. 18 00:00:59.200 --> 00:01:01.759 It really is talking about a concentrated burst of light 19 00:01:01.799 --> 00:01:04.640 that dwarfs the combined output of billions of stars billions, 20 00:01:04.799 --> 00:01:07.799 and it gets registered in the astronomical community as GRB 21 00:01:07.959 --> 00:01:10.959 two three zero nine zero six A, which. 22 00:01:10.760 --> 00:01:14.319 Is a highly peculiar immensely violent class of phenomena. 23 00:01:14.000 --> 00:01:17.239 Right, a short gamma ray burst. So okay, let's unpack 24 00:01:17.280 --> 00:01:20.599 this because trying to mentally process an explosion that outshines 25 00:01:20.599 --> 00:01:23.799 a galaxy, it requires looking at the actual mechanics of 26 00:01:23.799 --> 00:01:24.560 what triggers it. 27 00:01:24.480 --> 00:01:26.640 And the culprits. In this case, we're two neutron. 28 00:01:26.359 --> 00:01:29.840 Stars, dead crushed remnants of massive stars. 29 00:01:29.439 --> 00:01:32.879 Exactly stars that spiral together and collided hundreds of millions 30 00:01:32.879 --> 00:01:33.480 of years ago. 31 00:01:33.719 --> 00:01:36.439 We are going to map out exactly how an explosion 32 00:01:36.480 --> 00:01:40.120 of that magnitude happens. But more importantly, we're going to 33 00:01:40.159 --> 00:01:44.640 look at how this distant, chaotic violence is fundamentally connected 34 00:01:44.680 --> 00:01:45.879 to the jewelry. 35 00:01:45.480 --> 00:01:47.840 You wear and the iron and the blood flowing through 36 00:01:47.840 --> 00:01:48.760 your veins right now. 37 00:01:49.079 --> 00:01:53.239 Yeah, So, just starting with the sheer physics of what 38 00:01:53.359 --> 00:01:55.200 the Fermi satellite recorded that day. 39 00:01:55.280 --> 00:01:59.040 It really challenges our everyday understanding of scale. I mean, 40 00:01:59.040 --> 00:02:01.719 to get a blast that outshines of galaxy, you need 41 00:02:01.719 --> 00:02:05.879 a mechanism that converts mass into energy with terrifying. 42 00:02:05.439 --> 00:02:08.639 Efficiency, right, And that is where the neutron stars come in. 43 00:02:09.080 --> 00:02:12.719 Because we aren't talking about active fusing stars like our sun. 44 00:02:13.120 --> 00:02:16.879 We were looking at the absolute extreme limit of material density, the. 45 00:02:17.000 --> 00:02:18.560 Very limit before black hole. 46 00:02:18.479 --> 00:02:22.280 Forms, precisely when a giant star dies and its core collapses. 47 00:02:22.560 --> 00:02:25.680 That gravitational crush is so intense that electrons and protons 48 00:02:25.719 --> 00:02:26.919 are physically forced together. 49 00:02:26.960 --> 00:02:28.319 They just get mashed into neutrons. 50 00:02:28.360 --> 00:02:30.800 We'll mashed together to become neutrons, and the result is 51 00:02:30.840 --> 00:02:32.919 a sphere maybe ten or twelve. 52 00:02:32.639 --> 00:02:34.879 Miles across, basically the size of a small city. 53 00:02:34.960 --> 00:02:37.199 A small city, yeah yeah, but it contains the mass 54 00:02:37.199 --> 00:02:38.360 of an entire sun. 55 00:02:38.479 --> 00:02:42.120 Which is wild like a single teaspoon of neutrons star 56 00:02:42.199 --> 00:02:45.080 material would weigh what billions of tons? 57 00:02:45.120 --> 00:02:50.360 Billions of tons just one teaspoon, So hundreds of millions 58 00:02:50.360 --> 00:02:53.599 of years ago, two of these ultra dense remnants found 59 00:02:53.599 --> 00:02:56.039 themselves locked in a decaying orbit. 60 00:02:55.919 --> 00:02:57.199 Just circling each other. 61 00:02:57.120 --> 00:03:01.159 Circling, spiraling toward each other, accelerating to a significant fraction 62 00:03:01.240 --> 00:03:01.719 of the speed of. 63 00:03:01.759 --> 00:03:03.479 Light until they ultimately collided. 64 00:03:03.599 --> 00:03:07.400 In that kinetic impact and the resulting instantaneous release of 65 00:03:07.520 --> 00:03:11.000 high energy radiation that is what washed over the Fermi 66 00:03:11.039 --> 00:03:12.479 satellite in twenty twenty three. 67 00:03:12.800 --> 00:03:17.080 Just visualizing a city sized atomic nucleus crashing into another 68 00:03:17.120 --> 00:03:18.840 one at near light speed, it is. 69 00:03:18.840 --> 00:03:20.840 The ultimate cosmic hammer and anvil. 70 00:03:21.039 --> 00:03:22.840 Yeah, that's a perfect way to put it. But the 71 00:03:22.879 --> 00:03:25.479 blast didn't happen in a vacuum, which brings us to 72 00:03:25.520 --> 00:03:27.680 the actual location of the collision. 73 00:03:27.919 --> 00:03:30.039 The cosmic crime scene. 74 00:03:29.439 --> 00:03:32.759 Right, the cosmic crime scene, because this wasn't some localized 75 00:03:32.759 --> 00:03:35.439 event in our own galactic backyard, not at all. The 76 00:03:35.560 --> 00:03:38.960 environment where this happened is a faint galaxy situated inside 77 00:03:38.960 --> 00:03:42.080 a much larger group of galaxies, and it's a staggering 78 00:03:42.159 --> 00:03:44.759 eight point five billion light years away from us. 79 00:03:45.000 --> 00:03:49.000 The eight point five billion year travel time provides really 80 00:03:49.120 --> 00:03:52.680 essential context here because think about it, the Earth itself 81 00:03:52.719 --> 00:03:55.520 is only about four point five billion years old. 82 00:03:55.360 --> 00:03:57.159 So this light was already on its way. 83 00:03:57.560 --> 00:04:00.719 The high energy photons from this gamma ray burs had 84 00:04:00.759 --> 00:04:03.360 already been traveling through the void of space for four 85 00:04:03.360 --> 00:04:07.479 billion years before our solar system even coalesced from a cloud. 86 00:04:07.240 --> 00:04:09.400 Of dust, before there was even an Earth to eventually 87 00:04:09.479 --> 00:04:10.400 hit exactly. 88 00:04:10.879 --> 00:04:13.879 But locating an event that far back in time and 89 00:04:13.879 --> 00:04:17.920 that far away in space is an incredibly difficult piece 90 00:04:18.120 --> 00:04:19.920 of astronomical detective work. 91 00:04:20.000 --> 00:04:22.600 Because Fermi just gives you the general area right right. 92 00:04:22.839 --> 00:04:26.399 FORMI is a fantastic instrument for detecting gamma rays. But 93 00:04:26.480 --> 00:04:29.560 gamma rays are notoriously hard to focus. They don't bounce 94 00:04:29.600 --> 00:04:32.600 off traditional mirror. This blast tree through art They blastraight through. 95 00:04:32.800 --> 00:04:35.160 So SERMI can tell us that a massive burst happened, 96 00:04:35.199 --> 00:04:36.920 and it can give us a general patch of. 97 00:04:36.920 --> 00:04:40.199 Sky, but it can't pinpoint the exact street address. 98 00:04:40.439 --> 00:04:42.120 No, it's too wide of a net. 99 00:04:42.160 --> 00:04:43.800 It's kind of like hearing a sonic boom. 100 00:04:43.959 --> 00:04:45.240 Oh, that's a great analogy. 101 00:04:45.560 --> 00:04:48.639 You know, a jet just broke the sound barrier somewhere overhead, 102 00:04:49.040 --> 00:04:51.639 but you can't point to the exact cubic meter of 103 00:04:51.720 --> 00:04:53.959 air it happened in just by the sound alone. You 104 00:04:53.959 --> 00:04:55.519 have to look for the contrail. 105 00:04:55.279 --> 00:04:59.240 That is exactly it. And finding that cosmic contrail required 106 00:04:59.279 --> 00:05:02.759 bringing in two two vastly different observational tools. 107 00:05:02.600 --> 00:05:06.399 NASA's Chandra X ray Observatory and the Hubble Space Telescope. 108 00:05:06.600 --> 00:05:09.920 Right now, Hubble operates heavily in the visible and near 109 00:05:09.959 --> 00:05:13.560 infrared spectrum. It excels at showing us the architecture of 110 00:05:13.600 --> 00:05:14.519 the universe. 111 00:05:14.240 --> 00:05:16.480 The shapes and structures of the galaxies themselves. 112 00:05:16.600 --> 00:05:19.639 Yes, but to connect the gamma ray bursts to a 113 00:05:19.680 --> 00:05:22.399 specific galaxy astronomers. 114 00:05:21.720 --> 00:05:23.800 Needed Chandra because of the afterglow. 115 00:05:23.879 --> 00:05:27.800 Decisely after the initial gamma ray flash subsides the explosion 116 00:05:27.879 --> 00:05:30.720 leaves behind a feeding after glow of lower energy light, 117 00:05:31.240 --> 00:05:32.800 particularly X rays. 118 00:05:32.560 --> 00:05:36.519 And astronomy professor Jane Charlton highlighted a really critical reality 119 00:05:36.519 --> 00:05:39.879 about the specific observation he did. She said that without 120 00:05:39.920 --> 00:05:44.000 the incredibly precise X ray imaging capabilities of the Chandra observatory, 121 00:05:44.439 --> 00:05:47.279 this faint host galaxy would have been completely missed. 122 00:05:47.519 --> 00:05:49.680 Because without the X ray data, you just have a 123 00:05:49.680 --> 00:05:52.160 picture of thousands of distant galaxies. 124 00:05:51.759 --> 00:05:54.199 From Hubble, just a sea of smudges, a sea. 125 00:05:54.000 --> 00:05:57.160 Of smudges, and absolutely no way to know which one 126 00:05:57.199 --> 00:06:01.240 hosted the explosion. You need Chan to find the glowing 127 00:06:01.240 --> 00:06:04.720 embers to narrow it down right. What's fascinating here is 128 00:06:04.759 --> 00:06:09.399 how relying on a single observational method leaves you blind 129 00:06:09.639 --> 00:06:11.439 to the actual mechanics of the universe. 130 00:06:11.720 --> 00:06:13.920 You need the layered approach exactly. 131 00:06:14.279 --> 00:06:17.360 By layering the data, taking the high energy X ray 132 00:06:17.360 --> 00:06:20.800 pinpoint from Chandra and overlaying it onto the deep optical 133 00:06:20.839 --> 00:06:24.079 field captured by Hubble, astronomers could drop a literal pin 134 00:06:24.199 --> 00:06:27.040 on a map eight point five billion light years away. 135 00:06:27.160 --> 00:06:28.480 They found the host galaxy. 136 00:06:28.680 --> 00:06:32.600 We found it. But more importantly, Hubble's optical data revealed 137 00:06:32.639 --> 00:06:35.079 that this galaxy wasn't just sitting in isolation. 138 00:06:35.279 --> 00:06:37.680 It belongs to a larger group it does. 139 00:06:37.519 --> 00:06:39.839 And that entire group is currently in the middle of 140 00:06:39.879 --> 00:06:42.759 a massive, chaotic cosmic merger. 141 00:06:42.600 --> 00:06:45.480 A galactic pile up. Which is wild because when we 142 00:06:45.519 --> 00:06:48.879 think of galaxies, we usually picture these serene, majestic pinwheels, 143 00:06:49.160 --> 00:06:50.720 just slowly rotating in. 144 00:06:50.680 --> 00:06:54.000 The dark like our own Milky Way looks in artistic renderings, right. 145 00:06:54.519 --> 00:06:57.800 But the environment where this burst happened is the total 146 00:06:57.839 --> 00:07:01.279 opposite of serene. These galaxies are actively colliding. 147 00:07:01.360 --> 00:07:03.720 Their gravitational fields are interacting in real time. 148 00:07:03.839 --> 00:07:06.519 They are ripping material away from each other, and all 149 00:07:06.600 --> 00:07:10.040 that turbulence is stirring up massive, massive amounts of new 150 00:07:10.079 --> 00:07:10.759 star formation. 151 00:07:11.199 --> 00:07:16.800 And within this chaotic wreckage, astronomers isolated the exact location 152 00:07:16.920 --> 00:07:17.199 of the. 153 00:07:17.160 --> 00:07:19.839 Blast inside a structure known as a tible tale a 154 00:07:19.879 --> 00:07:22.439 tidle tail. Yes, so walk us through what a tidal 155 00:07:22.480 --> 00:07:26.279 tale actually is physically in the middle of a multi 156 00:07:26.319 --> 00:07:27.240 galaxy merger. 157 00:07:27.399 --> 00:07:29.560 To understand a title tale, we really have to look 158 00:07:29.600 --> 00:07:34.040 at the fluid mechanic of gravity on a massive scale. Galaxies, 159 00:07:34.079 --> 00:07:36.759 you have to remember, are predominantly empty space. 160 00:07:36.759 --> 00:07:39.199 Just populated by billions of stars. 161 00:07:38.879 --> 00:07:42.399 Stars, and vast reservoirs of coal, gas, and dust. So 162 00:07:42.439 --> 00:07:45.120 when two galaxies pass close to one another, they don't 163 00:07:45.160 --> 00:07:46.639 usually crash like solid objects. 164 00:07:46.680 --> 00:07:48.279 They don't just smashed together like rocks. 165 00:07:48.480 --> 00:07:53.240 No, Instead, their gravitational fields interlock. But gravity follows the 166 00:07:53.279 --> 00:07:54.360 inverse square. 167 00:07:54.120 --> 00:07:57.279 Law, meaning its strength drops off exponentially with distance. 168 00:07:57.839 --> 00:08:00.439 Exactly so, the side of a galaxy see that is 169 00:08:00.519 --> 00:08:05.000 closest to the intruding galaxy feels a vastly stronger gravitational 170 00:08:05.000 --> 00:08:06.800 pull than the side facing away. 171 00:08:06.839 --> 00:08:09.519 It's a differential pole, differential poll. Yeah, it's like taking 172 00:08:09.560 --> 00:08:12.199 two massive balls of taffy and bring them close together. 173 00:08:13.040 --> 00:08:15.759 The edges closest to each other grab on, and as 174 00:08:15.800 --> 00:08:19.240 the bodies continue their momentum, those edges get stretched out 175 00:08:19.279 --> 00:08:23.160 into long, stringy lines of sugar connecting the two main pieces. 176 00:08:23.399 --> 00:08:25.360 That is a brilliant way to visualize it. 177 00:08:25.759 --> 00:08:28.120 Only in this case, the taffy is made of millions 178 00:08:28.120 --> 00:08:31.199 of stars in interstellar gas, and the strings are hundreds 179 00:08:31.240 --> 00:08:32.759 of thousands of light years long. 180 00:08:33.039 --> 00:08:37.320 The taffy analogy perfectly captures the sheer stretching force involved. 181 00:08:37.919 --> 00:08:42.279 That differential gravitational pull literally strips the outer layers of 182 00:08:42.279 --> 00:08:44.759 the galaxies away, just heels it off, peels it off, 183 00:08:44.799 --> 00:08:49.279 drawing out these immense, sweeping ribbons of material into intergalactic space. 184 00:08:49.799 --> 00:08:51.759 Those ribbons are the tidal tails. 185 00:08:51.679 --> 00:08:54.679 The elongated shrapnel of a galactic interaction. 186 00:08:54.919 --> 00:08:57.799 And importantly, those tails are absolutely packed at the cold 187 00:08:57.840 --> 00:09:00.639 gas and dust that was formally just floating in the 188 00:09:00.679 --> 00:09:01.960 outer disks of the galaxy. 189 00:09:02.080 --> 00:09:04.120 So it's yanked out and funneled. 190 00:09:03.879 --> 00:09:07.360 Funneled into these narrow streams, and as it does, the 191 00:09:07.399 --> 00:09:09.159 gas violently compresses. 192 00:09:09.240 --> 00:09:12.039 And when you compress cold gas in space, you basically 193 00:09:12.080 --> 00:09:13.679 build a cosmic pressure cooker. 194 00:09:13.759 --> 00:09:14.440 You certainly do. 195 00:09:14.600 --> 00:09:17.840 The density spikes, the temperature rises, and you trigger a 196 00:09:18.000 --> 00:09:21.799 massive wave of new star formation, which brings us to 197 00:09:21.840 --> 00:09:26.000 a specific sequence of events proposed by researcher Simone di Quiara. 198 00:09:26.360 --> 00:09:28.440 Dikiara's timeline is fascinating. 199 00:09:28.559 --> 00:09:32.039 Yeah. He laid out this seven hundred million year timeline 200 00:09:32.039 --> 00:09:35.879 that connects the grand macro scale of this galaxy collision 201 00:09:36.279 --> 00:09:40.120 directly down to the microscale of those two neutron stars colliding. 202 00:09:40.360 --> 00:09:43.480 The timeline he outlines is a perfect demonstration of stellar 203 00:09:43.519 --> 00:09:46.320 evolution accelerated by a chaotic environment. 204 00:09:46.519 --> 00:09:49.399 So the clock starts roughly seven hundred million years before 205 00:09:49.399 --> 00:09:50.120 the gamma raypors. 206 00:09:50.279 --> 00:09:53.080 Right, the galaxies get emerged, the tidal forces stretch out 207 00:09:53.120 --> 00:09:55.799 the taffy, and a resulting compression in the tidal tail 208 00:09:56.120 --> 00:09:57.519 triggers the starburst phase. 209 00:09:57.720 --> 00:09:59.279 Just a massive ignition. 210 00:09:59.159 --> 00:10:02.759 Millions of new st ignite almost simultaneously within this ribbon 211 00:10:02.840 --> 00:10:05.799 of debris. But the key here is the type of 212 00:10:05.799 --> 00:10:06.639 stars being born. 213 00:10:06.759 --> 00:10:08.759 The compression favors a specific kind. 214 00:10:09.039 --> 00:10:12.720 The intense compression in a tidal tale heavily favors the 215 00:10:12.759 --> 00:10:17.120 creation of incredibly massive stars. We are talking O type 216 00:10:17.159 --> 00:10:20.440 and B type stars that are dozens of times more 217 00:10:20.480 --> 00:10:21.440 massive than our Sun. 218 00:10:21.679 --> 00:10:24.120 And the rule with stars is the bigger they are, 219 00:10:24.159 --> 00:10:25.600 the harder they fall, and the. 220 00:10:25.519 --> 00:10:26.960 Faster they burn through their fuel. 221 00:10:27.200 --> 00:10:30.600 Right, a star like our Sun might sip its hydrogen 222 00:10:30.759 --> 00:10:34.799 for ten billion years, but these massive giants born in 223 00:10:34.840 --> 00:10:38.440 the tidal tail, they are burning through their nuclear fuel 224 00:10:38.519 --> 00:10:39.720 at a ridiculous rate. 225 00:10:39.840 --> 00:10:43.720 They live fast and die young. Astronomically speaking, their life 226 00:10:43.720 --> 00:10:44.840 spans are mere. 227 00:10:44.600 --> 00:10:46.679 Blips, just a few million years. 228 00:10:46.480 --> 00:10:50.360 Within a few million years, these hyper massive stars exhaust 229 00:10:50.360 --> 00:10:54.320 the hydrogen in their cores, the outward pressure of nuclear fusion. 230 00:10:54.000 --> 00:10:55.759 Drops, and gravity takes over. 231 00:10:55.960 --> 00:10:58.200 The star can no longer support its own immense weight 232 00:10:58.240 --> 00:11:00.720 against the crush of gravity. The core collapses in a 233 00:11:00.759 --> 00:11:01.919 fraction of a second. 234 00:11:01.679 --> 00:11:05.960 And the outer layers rebound in a catastrophic supernova explosion. 235 00:11:05.679 --> 00:11:09.919 Leaving behind the crushed neutron star core we discussed earlier. Now, 236 00:11:10.000 --> 00:11:11.360 because stars often form in. 237 00:11:11.320 --> 00:11:13.559 Pairs, binary systems, yes. 238 00:11:13.679 --> 00:11:17.240 Binary systems, you frequently end up with two massive stars 239 00:11:17.679 --> 00:11:20.240 orbiting each other that both go supernova. 240 00:11:20.279 --> 00:11:23.440 Assuming the explosions don't just kick them apart entirely. 241 00:11:23.279 --> 00:11:26.240 Exactly, assuming they stay gravitationally bound, you are left with 242 00:11:26.279 --> 00:11:27.879 a compact binary. 243 00:11:27.440 --> 00:11:31.960 System, two dead neutron stars orbiting a common center of mass, 244 00:11:32.320 --> 00:11:34.679 just floating inside this tidal. 245 00:11:34.240 --> 00:11:35.840 Tail, orbiting in the dark. 246 00:11:35.960 --> 00:11:38.759 So the tidal tale essentially acts as a hyper efficient 247 00:11:38.840 --> 00:11:42.200 factory for producing pairs of dead neutron stars. 248 00:11:42.000 --> 00:11:43.879 A factory build from galactic wreckage. 249 00:11:43.919 --> 00:11:46.960 But they don't just immediately crash into each other. According 250 00:11:46.960 --> 00:11:50.559 to Dickyar's timeline, they spend hundreds of millions of years 251 00:11:50.600 --> 00:11:54.360 in a kind of agonizingly slow death spiral. Right, how 252 00:11:54.360 --> 00:11:57.559 does a binary pair of dead stars eventually close the distance? 253 00:11:57.639 --> 00:12:00.240 I mean, in a vacuum, shouldn't they just orbit forever? 254 00:12:00.440 --> 00:12:03.840 If we relied strictly on Newtonian physics, they would orbit forever. 255 00:12:04.399 --> 00:12:07.759 But in the realm of extreme gravity, Einstein's general relativity 256 00:12:07.759 --> 00:12:08.240 takes over. 257 00:12:08.480 --> 00:12:08.879 Okay. 258 00:12:09.080 --> 00:12:12.159 As these two incredibly dense masses orbit each other, they 259 00:12:12.200 --> 00:12:15.840 accelerate through the gravitational field, which creates ripples in the 260 00:12:15.879 --> 00:12:17.120 actual fabric. 261 00:12:16.759 --> 00:12:18.399 Of space time gravitational waves. 262 00:12:18.679 --> 00:12:22.360 Yes, gravitational waves. You can think of gravitational waves as 263 00:12:22.360 --> 00:12:25.679 a mechanism that physically bleeds kinetic energy away from the 264 00:12:25.720 --> 00:12:29.919 binary system, like friction almost sort of. Yes, As energy 265 00:12:29.960 --> 00:12:33.919 is radiated away into space, the orbit shrinks. It is 266 00:12:33.960 --> 00:12:36.039 a slow, relentless process. 267 00:12:36.159 --> 00:12:39.480 So for hundreds of millions of years, they bleed. 268 00:12:39.360 --> 00:12:43.200 Energy, spiraling closer and closer, faster and faster, until the 269 00:12:43.320 --> 00:12:44.559 orbit decays completely. 270 00:12:44.639 --> 00:12:47.200 And that is the climax of the seven hundred million 271 00:12:47.240 --> 00:12:51.440 year journey. The compact binary star merger. You touch the 272 00:12:51.440 --> 00:12:54.519 system violently, shares a part, and it triggers the massive 273 00:12:54.600 --> 00:12:57.879 short gamma ray bursts that Fermi saw in twenty twenty three. 274 00:12:58.360 --> 00:13:01.720 If we connect this to the bigger picture, Dikyure's hypothesis 275 00:13:01.759 --> 00:13:04.639 really redefines how we view the life cycle of a galaxy. 276 00:13:04.720 --> 00:13:07.440 How so well, the tidal interactions aren't merely the setting 277 00:13:07.440 --> 00:13:10.440 for this event. The gravitational disruption is the direct trigger. 278 00:13:10.480 --> 00:13:11.919 It's a chain reaction exactly. 279 00:13:12.000 --> 00:13:15.120 The chaotic merger forces the compression. The compression forces the 280 00:13:15.120 --> 00:13:18.480 massive star birth. The massive stars rapidly die to leave 281 00:13:18.559 --> 00:13:22.399 neutron stars, and the neutron stars decay into a catastrophic merger. 282 00:13:22.639 --> 00:13:26.679 The largest structures in the universe. Colliding galaxies are directly 283 00:13:26.720 --> 00:13:32.000 responsible for generating the most concentrated microscopic points of extreme energy. 284 00:13:32.200 --> 00:13:34.679 It is the ultimate cosmic domino effect. 285 00:13:34.320 --> 00:13:39.159 That is just incredible. But the final massive explosion, the merger, 286 00:13:39.559 --> 00:13:41.840 it doesn't just produce a blinding flash of light and 287 00:13:41.879 --> 00:13:42.919 then fade into history. 288 00:13:43.039 --> 00:13:44.799 No, it leaves a very permanent mark. 289 00:13:45.080 --> 00:13:48.879 That collision fundamentally alters the chemistry of the universe around it, 290 00:13:48.879 --> 00:13:52.480 because when those two neutron stars slam together, the physics 291 00:13:52.480 --> 00:13:55.799 get so extreme that they create a phenomenon called a killinova. 292 00:13:55.879 --> 00:13:56.960 A killinova, yes. 293 00:13:56.799 --> 00:14:01.159 And a killinova is basically the universe's premiere heavy metal forge. 294 00:14:01.480 --> 00:14:04.799 The term forge is incredibly accurate. There when we observe 295 00:14:04.879 --> 00:14:09.279 killinova emissions, we are seeing the brightly glowing, rapidly expanding 296 00:14:09.320 --> 00:14:12.519 halo of radioactive material ejected during. 297 00:14:12.320 --> 00:14:14.200 The collision, just blasting our words. 298 00:14:14.200 --> 00:14:16.200 And to understand why this is a forge, we have 299 00:14:16.279 --> 00:14:17.840 to look at how elements are created in. 300 00:14:17.799 --> 00:14:19.399 The first place, like in normal stars. 301 00:14:19.639 --> 00:14:23.840 Right, normal stars synthesize light elements hydrogen and helium, helium 302 00:14:23.879 --> 00:14:26.120 into carbon, oxygen all the way up to iron. 303 00:14:26.279 --> 00:14:28.919 But iron is the wall, right, the dead end. 304 00:14:29.240 --> 00:14:33.840 Iron is the absolute limit for normal stellar fusion. Fusing 305 00:14:33.879 --> 00:14:36.919 iron requires more energy than it releases, so a normal 306 00:14:36.960 --> 00:14:38.000 star just stops there. 307 00:14:38.600 --> 00:14:41.919 So to get past iron to create elements heavier than iron, 308 00:14:42.000 --> 00:14:46.200 like gold, platinum, or uranium, you need something way more intense. 309 00:14:46.320 --> 00:14:49.000 You need an environment with an overwhelming abundance of free 310 00:14:49.039 --> 00:14:51.360 neutrons and incomprehensible energy. 311 00:14:51.440 --> 00:14:54.320 Because neutrons have no electrical charge. Exactly, if you try 312 00:14:54.360 --> 00:14:57.960 to mash to positively charged atomic nuclei together, they just 313 00:14:58.039 --> 00:15:00.600 repel each other. But a neutron you can just slip 314 00:15:00.679 --> 00:15:03.600 right past the defenses and bury itself in the nucleus. 315 00:15:03.679 --> 00:15:06.679 That is the core mechanism of what astrophysicists call the 316 00:15:06.799 --> 00:15:10.720 rapid neutron capture process the R process. The R process. 317 00:15:11.120 --> 00:15:13.000 During the fraction of a second when the two neutron 318 00:15:13.039 --> 00:15:16.279 stars collide, the environment is flooded with a density of 319 00:15:16.279 --> 00:15:19.639 free neutrons that exists almost nowhere else in the universe. 320 00:15:19.320 --> 00:15:21.320 Just a total deluge of neutrons. 321 00:15:21.360 --> 00:15:25.000 Atomic nuclei are bombarded with these neutrons so rapidly that 322 00:15:25.039 --> 00:15:27.480 they capture them before they even have a chance to 323 00:15:27.559 --> 00:15:28.919 undergo radioactive decay. 324 00:15:29.000 --> 00:15:31.000 So the nucleus just balloons in size. 325 00:15:31.120 --> 00:15:34.919 It balloons, becomes highly unstable, and then finally decays into 326 00:15:35.000 --> 00:15:37.080 a stable, incredibly heavy element. 327 00:15:37.200 --> 00:15:40.120 And the kilinova is the site of this R process. 328 00:15:40.360 --> 00:15:43.360 The explosion creates elements like gold and platinum, and the 329 00:15:43.440 --> 00:15:46.639 kinetic force of the blast physically scatters them outward into 330 00:15:46.679 --> 00:15:48.759 the surrounding interstellar medium. 331 00:15:48.440 --> 00:15:51.440 Which actually solves a massive puzzle in astronomy too. It 332 00:15:51.480 --> 00:15:55.480 really does, because for years astronomers looking at interacting galaxies 333 00:15:55.639 --> 00:15:59.519 notice something strange. They were seeing heightened levels of heavy 334 00:15:59.559 --> 00:16:03.440 elements like gold and platinum, specifically located in the halos. 335 00:16:03.480 --> 00:16:07.080 The chaotic outer fringes of these merging galaxies, and it 336 00:16:07.080 --> 00:16:10.000 did make sense, right, Why is the heavy stuff floating 337 00:16:10.039 --> 00:16:12.080 way out in the cosmic suburbs exactly? 338 00:16:12.159 --> 00:16:16.360 And the observation of GRB two three zero nine zero 339 00:16:16.399 --> 00:16:20.440 six A within a tidal tail provides a highly elegant, 340 00:16:20.720 --> 00:16:22.679 observable solution to that mystery. 341 00:16:22.720 --> 00:16:23.679 It's the smoking gun. 342 00:16:23.960 --> 00:16:27.159 It is the interacting galaxies draw out the tidal tails 343 00:16:27.240 --> 00:16:30.399 into the outer halos. The tails greed the massive stars. 344 00:16:30.399 --> 00:16:34.759 The stars leave the neutron binaries, the binaries merge into kilnova. 345 00:16:34.320 --> 00:16:37.440 And there are process sprays those newly forged heavy elements 346 00:16:37.519 --> 00:16:40.000 directly into that outer galactic envelope. 347 00:16:40.080 --> 00:16:44.240 The environment forces the creation of the forge, exactly where 348 00:16:44.240 --> 00:16:45.519 we see the resulting metals. 349 00:16:45.600 --> 00:16:47.919 Here's where it gets really interesting, because we've been talking 350 00:16:47.919 --> 00:16:52.519 about galaxies eight point five billion light years away, but 351 00:16:52.639 --> 00:16:56.840 this cosmic alchemy is intimately tied to you, the listener, 352 00:16:57.039 --> 00:17:00.240 very intimately tied. Professor Jane Charlton reviewed the data from 353 00:17:00.240 --> 00:17:02.159 this event and noted that it gives us a rare 354 00:17:02.200 --> 00:17:05.359 glimpse into how destruction acts as a catalyst for creation. 355 00:17:05.920 --> 00:17:09.880 The universe doesn't just destroy, it aggressively. 356 00:17:09.319 --> 00:17:11.200 Recycled, aggressively recycles. 357 00:17:11.240 --> 00:17:14.279 I love that the recycling process is really the foundation 358 00:17:14.359 --> 00:17:18.559 of our physical reality. We tend to view massive cosmic 359 00:17:18.640 --> 00:17:22.799 explosions as endpoints, the death of stars right game over, 360 00:17:22.920 --> 00:17:25.759 But chemically speaking, they are seeding mechanisms. 361 00:17:25.920 --> 00:17:27.799 Think about the gold right here on Earth, like if 362 00:17:27.839 --> 00:17:30.039 you are wearing a gold ring right now, or just 363 00:17:30.079 --> 00:17:32.640 holding a smartphone that relies on trace amounts of gold 364 00:17:32.640 --> 00:17:33.480 and its microchips. 365 00:17:33.599 --> 00:17:36.079 Earth didn't make that gold, no, and our. 366 00:17:36.000 --> 00:17:40.319 Sun cannot make that gold. Every single atom of gold 367 00:17:40.319 --> 00:17:42.839 on this planet was forged in the rare process of 368 00:17:42.839 --> 00:17:44.160 a kilinovo. 369 00:17:43.799 --> 00:17:45.799 Which is astonishing to think about. 370 00:17:46.160 --> 00:17:49.440 Billions of years ago, somewhere in the cosmos, neutron stars 371 00:17:49.519 --> 00:17:52.759 smashed into each other, and the shrapnel from that distant 372 00:17:52.839 --> 00:17:56.279 violence eventually drifted into the cloud of gas that formed 373 00:17:56.279 --> 00:17:57.200 our solar system. 374 00:17:57.559 --> 00:18:01.359 You are interacting with the wreckage of a cosmic collision 375 00:18:01.440 --> 00:18:03.279 on a daily basis. 376 00:18:02.880 --> 00:18:04.759 And it goes deeper than the metal in your phone. 377 00:18:04.799 --> 00:18:06.240 It goes straight into your biology. 378 00:18:06.359 --> 00:18:10.759 Yes, Charlton made a point to connect this astrophysical process 379 00:18:11.279 --> 00:18:14.039 to the very physiological mechanisms keeping us alive. 380 00:18:14.240 --> 00:18:16.519 The heavier elements in our bodies. 381 00:18:16.119 --> 00:18:19.680 Particularly iron. Iron has an extraordinary origin It is the 382 00:18:19.720 --> 00:18:23.119 central atom in the heme group of hemoglobin. 383 00:18:22.559 --> 00:18:25.960 The protein in red blood cells that binds to oxygen. 384 00:18:26.200 --> 00:18:29.079 Exactly when you take a breath, oxygen from your lungs 385 00:18:29.079 --> 00:18:31.599 binds to the iron in your blood to be transported 386 00:18:31.599 --> 00:18:34.839 to every cell in your body. Without that specific atomic structure, 387 00:18:35.200 --> 00:18:37.599 respiration as we know it completely fails. 388 00:18:37.799 --> 00:18:39.359 And the origin of that iron. 389 00:18:39.279 --> 00:18:42.359 It was synthesized in the cores of dyeing massive stars 390 00:18:42.799 --> 00:18:46.640 just before they went supernova. The current estimate is that 391 00:18:46.680 --> 00:18:49.599 the iron coursing through your veins right now is an 392 00:18:49.640 --> 00:18:54.119 amalgamation of material forged in the explosive depths of roughly 393 00:18:54.200 --> 00:18:57.599 ten thousand different massive stars in the Milky Way's history. 394 00:18:57.920 --> 00:19:01.079 The human body is essentially a mosaic constructed from the 395 00:19:01.079 --> 00:19:04.599 remains of ten thousand dead stars. It is every time 396 00:19:04.640 --> 00:19:07.200 your heart pumps, you were relying on heavy elements that 397 00:19:07.240 --> 00:19:10.039 were forged in a pressure cooker billions of years before 398 00:19:10.079 --> 00:19:11.079 Earth even existed. 399 00:19:11.200 --> 00:19:14.880 Ten thousand stars had to live, burn fiercely, and detonate 400 00:19:15.000 --> 00:19:17.839 violently just to see the gas cloud that would eventually 401 00:19:17.880 --> 00:19:18.880