1 00:00:00,000 --> 00:00:01,360 Welcome back to Cosmos in a Pod, 2 00:00:01,360 --> 00:00:03,260 space and astronomy series, of course. 3 00:00:04,440 --> 00:00:06,520 Today we're gonna be diving deep into something 4 00:00:06,520 --> 00:00:08,680 I think will leave you terrified, 5 00:00:08,680 --> 00:00:11,360 but also like completely in awe. 6 00:00:11,360 --> 00:00:14,280 Supermassive black holes, ready to go explore. 7 00:00:14,280 --> 00:00:17,560 Always, always ready for a cosmic adventure. 8 00:00:17,560 --> 00:00:19,560 What kind of mysteries are we uncovering today? 9 00:00:19,560 --> 00:00:20,880 Well, we're not just talking about 10 00:00:20,880 --> 00:00:22,120 your average black holes, 11 00:00:22,120 --> 00:00:24,160 we're talking supermassive black holes, 12 00:00:24,160 --> 00:00:26,400 the kind that are like millions, 13 00:00:26,400 --> 00:00:28,400 even billions of times the mass of our sun. 14 00:00:28,400 --> 00:00:30,360 Ah, yes, the cosmic heavyweights, 15 00:00:30,360 --> 00:00:31,600 they're really something else. 16 00:00:31,600 --> 00:00:33,940 Exactly, and here's the thing, 17 00:00:33,940 --> 00:00:36,760 they're not just like passively sitting there 18 00:00:36,760 --> 00:00:39,160 in the centers of galaxies, 19 00:00:39,160 --> 00:00:41,780 they're actively shaping the galaxies they inhabit, 20 00:00:41,780 --> 00:00:43,280 almost like cosmic architects. 21 00:00:43,280 --> 00:00:44,880 Yeah, that's what's so fascinating, right? 22 00:00:44,880 --> 00:00:47,420 Their influence stretches way beyond 23 00:00:47,420 --> 00:00:49,000 just their immediate surroundings. 24 00:00:49,000 --> 00:00:50,520 Now, before we get too far ahead of ourselves, 25 00:00:50,520 --> 00:00:52,240 let's like take a step back, right? 26 00:00:52,240 --> 00:00:54,600 For anyone who might not be totally up to speed, 27 00:00:54,600 --> 00:00:55,780 can you break it down for us? 28 00:00:55,780 --> 00:00:58,200 What makes a black hole supermassive? 29 00:00:58,200 --> 00:00:59,040 Yeah, sure. 30 00:00:59,040 --> 00:01:01,120 So you're probably familiar with the basic idea 31 00:01:01,120 --> 00:01:01,960 of a black hole, 32 00:01:01,960 --> 00:01:04,360 a place in space where gravity is so strong 33 00:01:04,360 --> 00:01:06,820 that nothing, not even light, can escape. 34 00:01:06,820 --> 00:01:09,420 A supermassive black hole takes that concept 35 00:01:09,420 --> 00:01:11,420 and like, LLs it up to 11. 36 00:01:11,420 --> 00:01:13,880 We're talking objects with masses 37 00:01:13,880 --> 00:01:17,000 millions or even billions of times greater than our sun. 38 00:01:17,000 --> 00:01:18,760 Wow, so that's a completely different scale. 39 00:01:18,760 --> 00:01:20,880 Oh, absolutely, and all that mass 40 00:01:20,880 --> 00:01:23,480 equals some serious gravitational pull, 41 00:01:23,480 --> 00:01:25,840 the kind that dominates entire galaxies. 42 00:01:25,840 --> 00:01:27,160 So it's not just about size, 43 00:01:27,160 --> 00:01:29,200 it's the impact, the influence it has 44 00:01:29,200 --> 00:01:30,280 on everything around it. 45 00:01:30,280 --> 00:01:31,120 You got it. 46 00:01:31,120 --> 00:01:32,220 Think of our solar system, 47 00:01:32,220 --> 00:01:33,680 but instead of the sun in the middle, 48 00:01:33,680 --> 00:01:35,880 you've got this supermassive black hole 49 00:01:35,880 --> 00:01:38,800 dictating the movements of stars and gas clouds 50 00:01:38,800 --> 00:01:40,560 over these incredible deptances. 51 00:01:40,560 --> 00:01:44,120 Wow, that's, I mean, it's almost impossible to picture. 52 00:01:44,120 --> 00:01:45,740 But how do these things even form? 53 00:01:45,740 --> 00:01:47,260 I mean, where does all that mass come from 54 00:01:47,260 --> 00:01:48,100 in the first place? 55 00:01:48,100 --> 00:01:49,640 Well, that is one of the biggest questions 56 00:01:49,640 --> 00:01:51,000 in, well, all of astrophysics. 57 00:01:51,000 --> 00:01:53,680 We're talking about a cosmic mystery 58 00:01:53,680 --> 00:01:56,760 shrouded in darkness, you know, pun intended. 59 00:01:56,760 --> 00:01:58,800 One theory is that they formed directly 60 00:01:58,800 --> 00:02:01,520 from like giant gas clouds that collapsed 61 00:02:01,520 --> 00:02:03,360 way back in the early universe. 62 00:02:03,360 --> 00:02:05,200 So they basically skip the whole star phase 63 00:02:05,200 --> 00:02:06,600 and just go straight to black hole. 64 00:02:06,600 --> 00:02:08,920 Boom, right to black hole status. 65 00:02:08,920 --> 00:02:10,840 It's like, I don't know, 66 00:02:10,840 --> 00:02:13,080 going from a grain of sand to a mountain 67 00:02:13,080 --> 00:02:14,260 in a single step. 68 00:02:15,280 --> 00:02:17,680 Another theory is they start out smaller, 69 00:02:17,680 --> 00:02:19,880 you know, maybe leftovers from dead stars, 70 00:02:19,880 --> 00:02:21,400 and then they just gradually grow 71 00:02:21,400 --> 00:02:23,200 by pulling in stuff around them. 72 00:02:23,200 --> 00:02:25,100 The cosmic vacuum cleaner's just sucking up 73 00:02:25,100 --> 00:02:26,320 everything in their path. 74 00:02:26,320 --> 00:02:27,480 I like that analogy. 75 00:02:27,480 --> 00:02:29,480 And of course, we can't rule out the possibility 76 00:02:29,480 --> 00:02:33,020 of mergers, smaller black holes colliding 77 00:02:33,020 --> 00:02:36,280 and combining over, well, billions of years. 78 00:02:36,280 --> 00:02:39,440 So a combination of things happening like forever. 79 00:02:39,440 --> 00:02:40,800 It's a complex process, 80 00:02:40,800 --> 00:02:42,760 a puzzle we're still piecing together, 81 00:02:42,760 --> 00:02:44,680 but it's definitely one of the most fascinating 82 00:02:44,680 --> 00:02:46,120 puzzles in astronomy. 83 00:02:46,120 --> 00:02:47,720 I know we tend to think of black holes 84 00:02:47,720 --> 00:02:50,040 as these like destructive forces, 85 00:02:50,040 --> 00:02:52,560 but I've heard they actually play a pretty surprising role 86 00:02:52,560 --> 00:02:54,700 in shaping galaxies, is that right? 87 00:02:54,700 --> 00:02:57,120 It's true, they're a lot more 88 00:02:57,120 --> 00:02:58,800 than just cosmic vacuum cleaners. 89 00:02:58,800 --> 00:03:00,740 They actually act as regulators, 90 00:03:00,740 --> 00:03:04,040 influencing the life cycle of stars within their galaxies. 91 00:03:04,040 --> 00:03:05,840 So they're not just destroying things, 92 00:03:05,840 --> 00:03:09,140 they're actually contributing to the creation of new stars. 93 00:03:09,140 --> 00:03:10,500 That's the amazing part. 94 00:03:10,500 --> 00:03:12,080 It's a delicate balance. 95 00:03:12,080 --> 00:03:14,260 They can trigger star formation, 96 00:03:14,260 --> 00:03:15,640 and they can suppress it. 97 00:03:15,640 --> 00:03:17,200 It all depends on the circumstances. 98 00:03:17,200 --> 00:03:19,680 It's like they have this like cosmic thermostat 99 00:03:19,680 --> 00:03:22,880 fine tuning the conditions inside their galaxies. 100 00:03:22,880 --> 00:03:24,400 Okay, now I'm really interested. 101 00:03:24,400 --> 00:03:26,360 Tell me more about this cosmic thermostat. 102 00:03:26,360 --> 00:03:27,200 How does it work? 103 00:03:27,200 --> 00:03:30,460 Oh, one of the key processes is something called feedback. 104 00:03:30,460 --> 00:03:34,400 When a supermassive black hole is like actively feeding, 105 00:03:34,400 --> 00:03:36,940 pulling in huge amounts of gas and dust, 106 00:03:36,940 --> 00:03:39,520 it releases this enormous amount of energy. 107 00:03:39,520 --> 00:03:41,220 So it's like a cosmic engine, 108 00:03:41,220 --> 00:03:43,760 with all that fuel creating this powerful output. 109 00:03:43,760 --> 00:03:44,600 That's it, yeah. 110 00:03:44,600 --> 00:03:46,520 And this energy comes out in different ways, 111 00:03:46,520 --> 00:03:49,840 powerful jets of particles, intense radiation. 112 00:03:49,840 --> 00:03:51,600 And this is what affects star formation. 113 00:03:51,600 --> 00:03:53,760 Yeah, so picture it like this. 114 00:03:53,760 --> 00:03:55,680 These jets, they can heat up 115 00:03:55,680 --> 00:03:58,080 and even push away the very gas and dust 116 00:03:58,080 --> 00:04:00,480 that would usually clump together to form new stars. 117 00:04:00,480 --> 00:04:02,460 So basically the black hole's activity 118 00:04:02,460 --> 00:04:05,580 can actually prevent star formation in some areas. 119 00:04:05,580 --> 00:04:06,420 That's right. 120 00:04:06,420 --> 00:04:07,900 It might seem counterintuitive, 121 00:04:07,900 --> 00:04:10,520 but these forces, these destructive forces, 122 00:04:10,520 --> 00:04:13,220 they play a vital role in regulating the pace 123 00:04:13,220 --> 00:04:15,080 of star birth in a galaxy. 124 00:04:15,080 --> 00:04:16,160 That's incredible. 125 00:04:16,160 --> 00:04:17,800 Are there any other feedback mechanisms? 126 00:04:17,800 --> 00:04:19,040 Like what else is going on? 127 00:04:19,040 --> 00:04:19,880 Oh, there are. 128 00:04:19,880 --> 00:04:22,380 Even when a black hole isn't actively feeding, 129 00:04:22,380 --> 00:04:24,880 it can still exert a more subtle form of feedback. 130 00:04:24,880 --> 00:04:28,320 Imagine like a gentle breeze compared to a hurricane. 131 00:04:28,320 --> 00:04:30,400 This kind of feedback can gradually heat 132 00:04:30,400 --> 00:04:33,300 the surrounding gas over very long periods, 133 00:04:33,300 --> 00:04:35,720 preventing rapid star formation. 134 00:04:35,720 --> 00:04:38,120 It leads to like a slower, 135 00:04:38,120 --> 00:04:40,240 more gradual evolution of the galaxy. 136 00:04:40,240 --> 00:04:41,840 So it's this constant give and take, 137 00:04:41,840 --> 00:04:43,960 this interplay between the black hole 138 00:04:43,960 --> 00:04:45,040 and everything around it, 139 00:04:45,040 --> 00:04:48,600 shaping the galaxy over like billions of years. 140 00:04:48,600 --> 00:04:50,680 Exactly, a dynamic dance that, 141 00:04:50,680 --> 00:04:53,120 I mean, we're still trying to figure out all the steps, 142 00:04:53,120 --> 00:04:55,040 and it's not just star formation. 143 00:04:55,040 --> 00:04:55,880 Really? 144 00:04:55,880 --> 00:04:56,700 What else is there? 145 00:04:56,700 --> 00:04:58,140 What other rules do these black holes play 146 00:04:58,140 --> 00:04:59,160 in shaping their galaxies? 147 00:04:59,160 --> 00:05:00,440 Supermassive black holes. 148 00:05:00,440 --> 00:05:02,520 They have this profound impact 149 00:05:02,520 --> 00:05:05,560 on the entire structure of their host galaxies. 150 00:05:05,560 --> 00:05:08,020 Their huge gravity, it pulls in stars, 151 00:05:08,020 --> 00:05:11,240 it pulls in gas, creating this dense central bulges 152 00:05:11,240 --> 00:05:12,140 that we see. 153 00:05:12,140 --> 00:05:14,260 They even influence a galaxy shape, 154 00:05:14,260 --> 00:05:16,960 whether it becomes a spiral like our own Milky Way 155 00:05:16,960 --> 00:05:18,560 or an elliptical galaxy. 156 00:05:18,560 --> 00:05:20,600 So they're like cosmic sculptors. 157 00:05:20,600 --> 00:05:22,440 Shaping the distribution of matter 158 00:05:22,440 --> 00:05:24,840 in a galaxy over vast periods. 159 00:05:24,840 --> 00:05:25,840 I like that, yeah. 160 00:05:25,840 --> 00:05:27,200 They're not passive observers, 161 00:05:27,200 --> 00:05:28,680 they're active participants 162 00:05:28,680 --> 00:05:31,200 in this grand evolution of galaxies. 163 00:05:31,200 --> 00:05:33,000 Wow, this is like so fascinating. 164 00:05:33,000 --> 00:05:35,160 It makes me wonder, are there any specific examples 165 00:05:35,160 --> 00:05:37,480 of these supermassive black holes 166 00:05:37,480 --> 00:05:40,000 that really show their power and their influence? 167 00:05:40,000 --> 00:05:41,000 Oh, absolutely. 168 00:05:41,000 --> 00:05:42,540 There are some real celebrity 169 00:05:42,540 --> 00:05:44,560 supermassive black holes out there. 170 00:05:44,560 --> 00:05:46,880 Okay, I love a good cosmic celebrity story. 171 00:05:46,880 --> 00:05:47,720 Tell me more. 172 00:05:47,720 --> 00:05:49,520 Well, right in our own cosmic backyard, 173 00:05:49,520 --> 00:05:51,000 the center of the Milky Way, 174 00:05:51,000 --> 00:05:54,660 there's Sagittarius A, a supermassive black hole, 175 00:05:54,660 --> 00:05:57,640 about four million times the mass of our sun. 176 00:05:57,640 --> 00:06:00,240 Hold on, so our own galaxy has one of these at its center. 177 00:06:00,240 --> 00:06:01,920 It does, it's pretty quiet compared 178 00:06:01,920 --> 00:06:03,060 to some of the others out there, 179 00:06:03,060 --> 00:06:05,240 but still incredibly fascinating. 180 00:06:05,240 --> 00:06:07,760 I mean, it's amazing and a little scary, isn't it? 181 00:06:07,760 --> 00:06:09,280 What about some other famous examples? 182 00:06:09,280 --> 00:06:11,680 Well, one that really captured everyone's attention 183 00:06:11,680 --> 00:06:14,440 a while back is the supermassive black hole 184 00:06:14,440 --> 00:06:15,960 in the galaxy M87. 185 00:06:15,960 --> 00:06:17,640 Oh, right, that incredible image, 186 00:06:17,640 --> 00:06:20,200 the first picture of a black hole shadow. 187 00:06:20,200 --> 00:06:21,080 That's it. 188 00:06:21,080 --> 00:06:23,320 That image gave us the first direct proof 189 00:06:23,320 --> 00:06:26,360 of something that was once considered purely theoretical, 190 00:06:26,360 --> 00:06:29,060 the event horizon, the point of no return. 191 00:06:29,060 --> 00:06:30,200 It was such a powerful picture, 192 00:06:30,200 --> 00:06:31,200 it really makes you think, 193 00:06:31,200 --> 00:06:33,520 it's a reminder of just how mysterious 194 00:06:33,520 --> 00:06:35,320 and powerful these objects really are. 195 00:06:35,320 --> 00:06:37,980 Absolutely, and then there's TON 618. 196 00:06:37,980 --> 00:06:39,640 This one's a true monster. 197 00:06:39,640 --> 00:06:41,600 It's in a distant quasar, 198 00:06:41,600 --> 00:06:46,600 and it weighs in at a staggering 66 billion solar masses. 199 00:06:46,600 --> 00:06:49,840 66 billion, I mean, how is that even possible? 200 00:06:49,840 --> 00:06:52,680 Makes our own Milky Way's black hole look tiny, doesn't it? 201 00:06:52,680 --> 00:06:55,780 These examples are truly remarkable, 202 00:06:55,780 --> 00:06:56,920 but it makes me wonder, 203 00:06:56,920 --> 00:06:59,080 how do we study something we can't see? 204 00:06:59,080 --> 00:07:00,700 I mean, they don't emit light, 205 00:07:00,700 --> 00:07:02,240 so how do we even know they're there, 206 00:07:02,240 --> 00:07:03,680 let alone learn anything about them? 207 00:07:03,680 --> 00:07:05,480 Well, that's where things get really clever. 208 00:07:05,480 --> 00:07:06,980 We can't see them directly, 209 00:07:06,980 --> 00:07:09,600 but we can see how they affect things around them. 210 00:07:09,600 --> 00:07:13,040 So it's like a cosmic detective story, looking for clues. 211 00:07:13,040 --> 00:07:15,560 Exactly, one way is by studying the movement 212 00:07:15,560 --> 00:07:18,120 of stars and gas clouds that are orbiting around them. 213 00:07:18,120 --> 00:07:19,640 So we could literally see these objects 214 00:07:19,640 --> 00:07:22,200 being like whipped around by the black hole's gravity. 215 00:07:22,200 --> 00:07:25,200 Exactly, and we can also detect the radiation 216 00:07:25,200 --> 00:07:27,680 that's emitted by all that superheated matter 217 00:07:27,680 --> 00:07:29,440 spiraling into the black hole. 218 00:07:29,440 --> 00:07:31,320 It's like listening to the black hole song, 219 00:07:31,320 --> 00:07:32,900 you know, decoding its secrets 220 00:07:32,900 --> 00:07:34,960 through the different frequencies of light. 221 00:07:34,960 --> 00:07:39,280 And in recent years, we've got this amazing new tool, 222 00:07:39,280 --> 00:07:40,840 gravitational waves. 223 00:07:40,840 --> 00:07:44,080 Oh yeah, those ripples in space time that Einstein predicted. 224 00:07:44,080 --> 00:07:47,080 Do those help us study supermassive black holes? 225 00:07:47,080 --> 00:07:48,520 You bet they do. 226 00:07:48,520 --> 00:07:51,360 Detecting gravitational waves from merging black holes 227 00:07:51,360 --> 00:07:54,980 has opened up a whole new way of looking at the universe. 228 00:07:54,980 --> 00:07:57,080 It lets us measure the masses and spins 229 00:07:57,080 --> 00:07:59,640 of these black holes with incredible accuracy. 230 00:07:59,640 --> 00:08:01,760 It's amazing to think that we can study these things 231 00:08:01,760 --> 00:08:02,840 in so many different ways. 232 00:08:02,840 --> 00:08:04,680 It's a real testament to human ingenuity. 233 00:08:04,680 --> 00:08:07,080 Absolutely, and yet for everything we've learned, 234 00:08:07,080 --> 00:08:08,560 there are still so many mysteries 235 00:08:08,560 --> 00:08:10,320 surrounding these supermassive black holes. 236 00:08:10,320 --> 00:08:11,360 Oh, I bet. 237 00:08:11,360 --> 00:08:12,920 What are some of the big questions 238 00:08:12,920 --> 00:08:14,920 that scientists are still trying to answer? 239 00:08:14,920 --> 00:08:16,600 What are the puzzles they're working on? 240 00:08:16,600 --> 00:08:18,320 Well, one of the biggest ones is, 241 00:08:18,320 --> 00:08:20,000 how do these things grow so fast? 242 00:08:20,000 --> 00:08:22,280 We see these incredibly massive black holes 243 00:08:22,280 --> 00:08:23,720 in the very early universe, 244 00:08:23,720 --> 00:08:25,320 and it just doesn't quite fit 245 00:08:25,320 --> 00:08:27,440 with our models of black hole growth. 246 00:08:27,440 --> 00:08:30,320 So it's like finding a fully grown oak tree 247 00:08:30,320 --> 00:08:32,500 in a forest that's only a few years old. 248 00:08:32,500 --> 00:08:33,840 Something's not adding up. 249 00:08:33,840 --> 00:08:35,640 Right, and then there's the relationship 250 00:08:35,640 --> 00:08:38,820 between supermassive black holes and dark matter. 251 00:08:38,820 --> 00:08:41,120 I've heard of dark matter, this mysterious stuff 252 00:08:41,120 --> 00:08:43,520 that makes up a huge part of the universe, 253 00:08:43,520 --> 00:08:45,960 but how does it connect to black holes? 254 00:08:45,960 --> 00:08:47,880 Well, we know that galaxies are surrounded 255 00:08:47,880 --> 00:08:50,200 by these vast halos of dark matter, 256 00:08:50,200 --> 00:08:52,080 and it's looking more and more likely 257 00:08:52,080 --> 00:08:54,080 that there's this kind of dynamic interplay 258 00:08:54,080 --> 00:08:57,060 between the dark matter and the supermassive black holes 259 00:08:57,060 --> 00:08:58,680 at the centers of galaxies. 260 00:08:58,680 --> 00:09:00,680 So they could be influencing each other, 261 00:09:00,680 --> 00:09:01,920 like one affecting the other. 262 00:09:01,920 --> 00:09:03,080 That's the idea. 263 00:09:03,080 --> 00:09:04,900 Some theories suggest that dark matter 264 00:09:04,900 --> 00:09:07,360 could even be fueling the growth of these black holes, 265 00:09:07,360 --> 00:09:10,960 providing a steady stream of invisible food 266 00:09:10,960 --> 00:09:11,960 for them to consume. 267 00:09:11,960 --> 00:09:14,620 A hidden food source for these cosmic giants. 268 00:09:14,620 --> 00:09:15,480 Exactly. 269 00:09:15,480 --> 00:09:17,620 It's still early days in this research, 270 00:09:17,620 --> 00:09:19,800 but it has the potential to change 271 00:09:19,800 --> 00:09:22,600 how we understand both dark matter 272 00:09:22,600 --> 00:09:24,600 and supermassive black holes. 273 00:09:24,600 --> 00:09:25,960 This is just mind blowing. 274 00:09:25,960 --> 00:09:27,600 It seems like every answer we find 275 00:09:27,600 --> 00:09:29,640 just leads to more questions. 276 00:09:29,640 --> 00:09:30,640 That's the fun part. 277 00:09:30,640 --> 00:09:32,720 It's a constant journey of discovery. 278 00:09:32,720 --> 00:09:34,040 Exactly. 279 00:09:34,040 --> 00:09:35,440 Speaking of unanswered questions, 280 00:09:35,440 --> 00:09:38,680 is there anything else about these supermassive black holes 281 00:09:38,680 --> 00:09:41,400 that is still stumping the scientists? 282 00:09:41,400 --> 00:09:44,800 One more big puzzle is the possible existence 283 00:09:44,800 --> 00:09:47,320 of something called intermediate mass black holes. 284 00:09:47,320 --> 00:09:48,120 And those are? 285 00:09:48,120 --> 00:09:50,480 So we know about the stellar mass black holes, right? 286 00:09:50,480 --> 00:09:52,840 The ones that are a few times heavier than our sun. 287 00:09:52,840 --> 00:09:54,320 And we have the supermassive ones, 288 00:09:54,320 --> 00:09:56,960 the ones that are millions or billions of times heavier. 289 00:09:56,960 --> 00:09:59,760 But there seems to be this missing piece in the middle. 290 00:09:59,760 --> 00:10:00,720 Like a missing link? 291 00:10:00,720 --> 00:10:01,680 That's it. 292 00:10:01,680 --> 00:10:03,560 We haven't found any solid evidence 293 00:10:03,560 --> 00:10:06,720 of black holes with masses in between those two extremes, 294 00:10:06,720 --> 00:10:08,440 the kind that would bridge that gap. 295 00:10:08,440 --> 00:10:10,160 So it's like a cosmic treasure hunt then. 296 00:10:10,160 --> 00:10:11,040 Exactly. 297 00:10:11,040 --> 00:10:12,920 Maybe they're out there hiding in plain sight. 298 00:10:12,920 --> 00:10:15,920 Or maybe there's something about how black holes form 299 00:10:15,920 --> 00:10:18,800 that just prevents them from forming at that size. 300 00:10:18,800 --> 00:10:19,680 It's a mystery. 301 00:10:19,680 --> 00:10:21,840 And astronomers are still searching for the answer. 302 00:10:21,840 --> 00:10:25,720 It's incredible to think about how much we still 303 00:10:25,720 --> 00:10:27,120 don't know about these objects. 304 00:10:27,120 --> 00:10:30,240 They really are like windows into the most extreme parts 305 00:10:30,240 --> 00:10:31,080 of the universe. 306 00:10:31,080 --> 00:10:33,440 And they push our understanding of physics to the limit, 307 00:10:33,440 --> 00:10:34,360 that's for sure. 308 00:10:34,360 --> 00:10:36,160 This has been an incredible journey so far. 309 00:10:36,160 --> 00:10:40,720 We've covered so much from how supermassive black holes form 310 00:10:40,720 --> 00:10:43,920 to their effects on galaxies and all the mysteries 311 00:10:43,920 --> 00:10:44,640 surrounding them. 312 00:10:44,640 --> 00:10:45,920 It's been a great discussion. 313 00:10:45,920 --> 00:10:47,440 And we're just getting started. 314 00:10:47,440 --> 00:10:48,640 That's right. 315 00:10:48,640 --> 00:10:50,840 But we'll have to pick up where we left off next time. 316 00:10:50,840 --> 00:10:51,520 Don't worry. 317 00:10:51,520 --> 00:10:54,160 In our next deep dive, we'll be exploring even more 318 00:10:54,160 --> 00:10:57,240 mind-blowing aspects of these amazing objects, 319 00:10:57,240 --> 00:10:59,960 ready to jump back into those cosmic mysteries. 320 00:10:59,960 --> 00:11:00,960 You bet. 321 00:11:00,960 --> 00:11:03,280 Last time we were talking about those intermediate mass 322 00:11:03,280 --> 00:11:05,560 black holes, the, you called them 323 00:11:05,560 --> 00:11:08,200 the missing link in the black hole family tree. 324 00:11:08,200 --> 00:11:11,200 Have there been any new discoveries, anything exciting 325 00:11:11,200 --> 00:11:12,400 happening on that front? 326 00:11:12,400 --> 00:11:13,160 Oh, yeah. 327 00:11:13,160 --> 00:11:15,960 It's a really hot area of research right now. 328 00:11:15,960 --> 00:11:20,520 Lots of tantalizing clues and possible candidates popping up. 329 00:11:20,520 --> 00:11:21,920 Some astronomers think they might 330 00:11:21,920 --> 00:11:24,680 have found evidence for these intermediate mass black holes 331 00:11:24,680 --> 00:11:27,960 hiding out in the centers of really dense star clusters. 332 00:11:27,960 --> 00:11:29,200 That makes sense, right? 333 00:11:29,200 --> 00:11:32,360 I mean, star clusters have so many stars packed together. 334 00:11:32,360 --> 00:11:34,760 Wouldn't that be like the perfect place for a black hole 335 00:11:34,760 --> 00:11:37,400 to grow and feast? 336 00:11:37,400 --> 00:11:41,440 Exactly, like a cosmic buffet table for hungry black holes. 337 00:11:41,440 --> 00:11:43,960 And there's another interesting idea floating around. 338 00:11:43,960 --> 00:11:46,200 Maybe these intermediate mass black holes, 339 00:11:46,200 --> 00:11:49,040 they could be the seeds for the supermassive ones 340 00:11:49,040 --> 00:11:50,920 we see in the hearts of galaxies. 341 00:11:50,920 --> 00:11:53,000 So instead of starting from scratch, 342 00:11:53,000 --> 00:11:56,200 these supermassive black holes could get a head start 343 00:11:56,200 --> 00:11:59,120 if they begin as these intermediate mass black holes. 344 00:11:59,120 --> 00:11:59,620 Exactly. 345 00:11:59,620 --> 00:12:02,240 It's like giving them a boost up the cosmic ladder. 346 00:12:02,240 --> 00:12:02,920 That's so cool. 347 00:12:02,920 --> 00:12:06,680 It really paints a picture of this interconnected universe, 348 00:12:06,680 --> 00:12:08,600 where all these different types of black holes 349 00:12:08,600 --> 00:12:10,160 could be linked across time. 350 00:12:10,160 --> 00:12:12,400 It's a humbling thought, for sure. 351 00:12:12,400 --> 00:12:14,600 And it really highlights just how much we still 352 00:12:14,600 --> 00:12:16,960 don't know about how the universe works. 353 00:12:16,960 --> 00:12:19,240 Speaking of humbling, we were talking 354 00:12:19,240 --> 00:12:21,960 before about the relationship between supermassive black 355 00:12:21,960 --> 00:12:23,840 holes and dark matter. 356 00:12:23,840 --> 00:12:25,360 I've always been fascinated by that. 357 00:12:25,360 --> 00:12:26,800 Can you tell me more about that connection? 358 00:12:26,800 --> 00:12:27,720 Of course. 359 00:12:27,720 --> 00:12:30,800 So dark matter, it's one of the biggest mysteries in, well, 360 00:12:30,800 --> 00:12:32,880 pretty much all of astrophysics. 361 00:12:32,880 --> 00:12:35,280 It doesn't interact with light, so we can't see it. 362 00:12:35,280 --> 00:12:36,600 But we know it's out there because 363 00:12:36,600 --> 00:12:39,680 of its gravitational effects on the stuff we can see. 364 00:12:39,680 --> 00:12:42,160 It's like this invisible scaffolding holding everything 365 00:12:42,160 --> 00:12:42,800 together. 366 00:12:42,800 --> 00:12:43,980 Great analogy. 367 00:12:43,980 --> 00:12:46,480 And we think that galaxies are embedded 368 00:12:46,480 --> 00:12:48,520 in these vast halos of dark matter. 369 00:12:48,520 --> 00:12:51,280 So these halos, it's like invisible cocoons 370 00:12:51,280 --> 00:12:52,440 surrounding the galaxy. 371 00:12:52,440 --> 00:12:54,020 Yeah, exactly. 372 00:12:54,020 --> 00:12:57,080 And here's where things get really interesting. 373 00:12:57,080 --> 00:13:01,080 There's this growing suspicion that these dark matter halos 374 00:13:01,080 --> 00:13:04,160 could be playing a big role in how supermassive black holes 375 00:13:04,160 --> 00:13:05,240 form and grow. 376 00:13:05,240 --> 00:13:06,520 I'm all ears. 377 00:13:06,520 --> 00:13:09,200 How could something we can't see be influencing something 378 00:13:09,200 --> 00:13:10,680 as powerful as a black hole? 379 00:13:10,680 --> 00:13:13,400 OK, so one possibility is that these dark matter particles, 380 00:13:13,400 --> 00:13:15,600 as they bump into each other, they lose energy 381 00:13:15,600 --> 00:13:17,800 and start to spiral inwards towards the center 382 00:13:17,800 --> 00:13:18,720 of the galaxy. 383 00:13:18,720 --> 00:13:19,720 And then what happens? 384 00:13:19,720 --> 00:13:21,560 What happens when they get close to the black hole 385 00:13:21,560 --> 00:13:22,360 at the center? 386 00:13:22,360 --> 00:13:24,440 Well, as they get closer and closer to the black hole, 387 00:13:24,440 --> 00:13:26,760 they can get so packed together that they form something 388 00:13:26,760 --> 00:13:30,000 called a dark matter spike. 389 00:13:30,000 --> 00:13:31,080 A dark matter spike? 390 00:13:31,080 --> 00:13:31,720 I've never heard of that. 391 00:13:31,720 --> 00:13:32,240 What is it? 392 00:13:32,240 --> 00:13:35,160 Imagine a huge concentration of dark matter 393 00:13:35,160 --> 00:13:38,200 just surrounding the black hole, like a dense invisible cloud. 394 00:13:38,200 --> 00:13:41,000 So it's like a hidden food source for the black hole. 395 00:13:41,000 --> 00:13:41,920 You got it. 396 00:13:41,920 --> 00:13:43,880 This concentrated dark matter could 397 00:13:43,880 --> 00:13:47,560 be getting devoured by the black hole, 398 00:13:47,560 --> 00:13:51,200 helping it grow over, well, billions and billions of years. 399 00:13:51,200 --> 00:13:52,700 So these supermassive black holes 400 00:13:52,700 --> 00:13:56,240 could be growing not just by eating stars and gas, 401 00:13:56,240 --> 00:14:00,480 but also by feeding on this invisible dark matter. 402 00:14:00,480 --> 00:14:02,120 That's one of the leading theories. 403 00:14:02,120 --> 00:14:04,760 And it really shows you how interconnected everything is, 404 00:14:04,760 --> 00:14:05,080 right? 405 00:14:05,080 --> 00:14:06,460 Something we can't even see could 406 00:14:06,460 --> 00:14:09,360 be having a huge impact on these powerful objects. 407 00:14:09,360 --> 00:14:13,240 It's like a hidden web, a cosmic dance between the visible 408 00:14:13,240 --> 00:14:14,200 and the invisible. 409 00:14:14,200 --> 00:14:15,120 Love that. 410 00:14:15,120 --> 00:14:18,200 And it really emphasizes how much more there is out there 411 00:14:18,200 --> 00:14:20,280 to discover and understand. 412 00:14:20,280 --> 00:14:22,040 This is all so mind blowing. 413 00:14:22,040 --> 00:14:25,320 It makes you realize that we're really just getting started. 414 00:14:25,320 --> 00:14:26,720 And for all the amazing things we've 415 00:14:26,720 --> 00:14:28,280 learned about these black holes, there's 416 00:14:28,280 --> 00:14:29,640 still so much we don't know. 417 00:14:29,640 --> 00:14:30,280 Absolutely. 418 00:14:30,280 --> 00:14:32,600 And that's what makes it so exciting, wouldn't you say? 419 00:14:32,600 --> 00:14:34,560 Every new discovery just opens up 420 00:14:34,560 --> 00:14:37,960 a whole new world of questions and possibilities. 421 00:14:37,960 --> 00:14:39,200 Speaking of new discoveries, I've 422 00:14:39,200 --> 00:14:42,200 been hearing a lot about this thing called the Event Horizon 423 00:14:42,200 --> 00:14:43,240 Telescope. 424 00:14:43,240 --> 00:14:45,320 Can you tell me a bit about that and what 425 00:14:45,320 --> 00:14:49,080 it's doing to help us learn more about supermassive black holes? 426 00:14:49,080 --> 00:14:51,600 Oh, the Event Horizon Telescope, or EHT, 427 00:14:51,600 --> 00:14:54,920 that's one of the most ambitious projects in, well, 428 00:14:54,920 --> 00:14:56,280 maybe all of science. 429 00:14:56,280 --> 00:14:57,640 It's not just one telescope. 430 00:14:57,640 --> 00:15:00,880 It's this whole global network of radio telescopes 431 00:15:00,880 --> 00:15:02,080 that are all working together. 432 00:15:02,080 --> 00:15:04,240 Ooh, that sounds incredible. 433 00:15:04,240 --> 00:15:07,520 Why go to all that trouble to build this worldwide network 434 00:15:07,520 --> 00:15:08,240 of telescopes? 435 00:15:08,240 --> 00:15:10,160 It all comes down to resolution. 436 00:15:10,160 --> 00:15:12,680 It's about seeing the fine details. 437 00:15:12,680 --> 00:15:15,520 By combining the signals from all these different telescopes 438 00:15:15,520 --> 00:15:18,360 across the globe, the EHT can see things 439 00:15:18,360 --> 00:15:20,520 in incredible detail, the kind of detail 440 00:15:20,520 --> 00:15:23,080 you need to peer right into the heart of a galaxy 441 00:15:23,080 --> 00:15:26,600 and see the regions around a supermassive black hole. 442 00:15:26,600 --> 00:15:28,800 It's like having a cosmic zoom lens, right? 443 00:15:28,800 --> 00:15:31,440 Seeing things that would be impossible to see otherwise. 444 00:15:31,440 --> 00:15:32,440 Exactly. 445 00:15:32,440 --> 00:15:34,520 And remember, a few years back, the EHT 446 00:15:34,520 --> 00:15:37,800 captured that amazing image of the supermassive black hole 447 00:15:37,800 --> 00:15:39,640 at the center of the galaxy, M87. 448 00:15:39,640 --> 00:15:41,800 Oh, yeah, the first picture of a black hole shadow. 449 00:15:41,800 --> 00:15:43,400 That was a huge deal, wasn't it? 450 00:15:43,400 --> 00:15:44,800 It was a real turning point. 451 00:15:44,800 --> 00:15:47,480 It gave us the first direct visual proof 452 00:15:47,480 --> 00:15:50,520 that black holes and their event horizons, 453 00:15:50,520 --> 00:15:52,760 the point of no return, actually exist. 454 00:15:52,760 --> 00:15:55,800 We went from theory to, well, to actually seeing it. 455 00:15:55,800 --> 00:15:59,240 A real testament to human ingenuity and collaboration. 456 00:15:59,240 --> 00:16:02,160 And I'm sure the EHT has even more exciting observations 457 00:16:02,160 --> 00:16:03,080 planned for the future. 458 00:16:03,080 --> 00:16:04,080 Oh, absolutely. 459 00:16:04,080 --> 00:16:07,360 The EHT is constantly getting upgraded and refined. 460 00:16:07,360 --> 00:16:09,000 And astronomers are using it to look 461 00:16:09,000 --> 00:16:12,120 at other supermassive black holes in even greater detail. 462 00:16:12,120 --> 00:16:15,440 So we can expect even more incredible images and insights 463 00:16:15,440 --> 00:16:17,200 into these mind-boggling objects. 464 00:16:17,200 --> 00:16:18,000 You bet. 465 00:16:18,000 --> 00:16:20,520 The EHT is going to revolutionize our understanding 466 00:16:20,520 --> 00:16:21,800 of black holes, that's for sure. 467 00:16:21,800 --> 00:16:23,080 This is all so exciting. 468 00:16:23,080 --> 00:16:25,520 It feels like we're living in a golden age of black hole 469 00:16:25,520 --> 00:16:28,880 research with new discoveries being made all the time. 470 00:16:28,880 --> 00:16:31,440 And it's not just about black holes themselves, right? 471 00:16:31,440 --> 00:16:34,560 By studying them, we're pushing the limits of physics, 472 00:16:34,560 --> 00:16:36,600 testing our theories about gravity, 473 00:16:36,600 --> 00:16:39,920 and getting a better grasp of, well, the basic laws that 474 00:16:39,920 --> 00:16:41,480 govern the entire universe. 475 00:16:41,480 --> 00:16:45,240 It's this constant search for knowledge driven by our, 476 00:16:45,240 --> 00:16:47,440 I don't know, our need to understand the universe. 477 00:16:47,440 --> 00:16:48,440 Exactly. 478 00:16:48,440 --> 00:16:51,920 That's what drives us to invent these incredible technologies, 479 00:16:51,920 --> 00:16:54,280 to build bigger and better telescopes, 480 00:16:54,280 --> 00:16:57,960 and to work together to solve these cosmic mysteries. 481 00:16:57,960 --> 00:17:00,360 This has been such an incredible journey so far. 482 00:17:00,360 --> 00:17:01,560 But I know we're not done yet. 483 00:17:01,560 --> 00:17:03,320 We still have so much more to explore. 484 00:17:03,320 --> 00:17:04,160 That's right. 485 00:17:04,160 --> 00:17:07,040 Hang on tight, because in our next installment, 486 00:17:07,040 --> 00:17:09,120 we're going to go even deeper into the mysteries 487 00:17:09,120 --> 00:17:11,240 of these supermassive black holes. 488 00:17:11,240 --> 00:17:13,480 We'll be talking about their bizarre properties, 489 00:17:13,480 --> 00:17:16,760 their influence on galaxies, and all the mind-boggling 490 00:17:16,760 --> 00:17:18,880 possibilities they hold for understanding 491 00:17:18,880 --> 00:17:20,800 the universe around us. 492 00:17:20,800 --> 00:17:23,120 All right, back for more cosmic adventures. 493 00:17:23,120 --> 00:17:25,320 You've really painted a mind-blowing picture 494 00:17:25,320 --> 00:17:28,000 of how powerful these supermassive black holes are, 495 00:17:28,000 --> 00:17:29,440 not just in their immediate area, 496 00:17:29,440 --> 00:17:32,720 but shaping entire galaxies. 497 00:17:32,720 --> 00:17:33,800 It's amazing. 498 00:17:33,800 --> 00:17:35,320 And we're just getting warmed up. 499 00:17:35,320 --> 00:17:36,920 Trust me, there's still so much more 500 00:17:36,920 --> 00:17:40,520 to learn about these enigmatic objects. 501 00:17:40,520 --> 00:17:41,720 Well, let's dive in. 502 00:17:41,720 --> 00:17:43,960 You were saying before that studying black holes 503 00:17:43,960 --> 00:17:46,480 can really push the limits of physics, right? 504 00:17:46,480 --> 00:17:48,000 Can you tell me more about that? 505 00:17:48,000 --> 00:17:50,560 How are they challenging our current understanding 506 00:17:50,560 --> 00:17:51,680 of the universe? 507 00:17:51,680 --> 00:17:53,840 Well, one of the most fundamental ways 508 00:17:53,840 --> 00:17:56,520 is through their extreme gravity, right? 509 00:17:56,520 --> 00:17:59,920 I mean, we're talking regions of space where gravity is so 510 00:17:59,920 --> 00:18:02,960 strong that it actually warps spacetime itself. 511 00:18:02,960 --> 00:18:04,000 Spacetime. 512 00:18:04,000 --> 00:18:05,280 I've heard that term before. 513 00:18:05,280 --> 00:18:07,040 But can you give me a quick refresher? 514 00:18:07,040 --> 00:18:07,540 Sure. 515 00:18:07,540 --> 00:18:10,880 Think of spacetime as the fabric of the universe, OK? 516 00:18:10,880 --> 00:18:12,880 It's this four-dimensional concept 517 00:18:12,880 --> 00:18:15,120 that combines the three dimensions of space 518 00:18:15,120 --> 00:18:16,280 with the dimension of time. 519 00:18:16,280 --> 00:18:18,560 So instead of thinking of space and time separately, 520 00:18:18,560 --> 00:18:21,560 we're combining them into this unified fabric. 521 00:18:21,560 --> 00:18:22,280 That's it. 522 00:18:22,280 --> 00:18:24,720 And massive objects, like stars and planets, 523 00:18:24,720 --> 00:18:27,720 they create a kind of like a dent in this fabric 524 00:18:27,720 --> 00:18:30,560 that causes other objects to move towards them, which 525 00:18:30,560 --> 00:18:32,640 is what we experience as gravity. 526 00:18:32,640 --> 00:18:35,720 So gravity is like a warp in the fabric of spacetime. 527 00:18:35,720 --> 00:18:36,560 Exactly. 528 00:18:36,560 --> 00:18:39,000 And black holes, well, they take this warping 529 00:18:39,000 --> 00:18:40,560 to a whole other level. 530 00:18:40,560 --> 00:18:42,520 Their gravity is so intense that it 531 00:18:42,520 --> 00:18:45,960 creates this bottomless pit in spacetime, 532 00:18:45,960 --> 00:18:48,120 a singularity where nothing can escape. 533 00:18:48,120 --> 00:18:51,000 Whoa, it's like a cosmic rip in the fabric of reality. 534 00:18:51,000 --> 00:18:52,320 You could say that. 535 00:18:52,320 --> 00:18:54,480 And this extreme warping of spacetime, 536 00:18:54,480 --> 00:18:57,240 it has huge implications for how we understand physics. 537 00:18:57,240 --> 00:19:00,440 Like it challenges our ideas about cause and effect. 538 00:19:00,440 --> 00:19:02,960 Events that happen inside a black hole, well, 539 00:19:02,960 --> 00:19:04,800 they might be forever disconnected 540 00:19:04,800 --> 00:19:06,360 from the rest of the universe. 541 00:19:06,360 --> 00:19:07,480 I mean, it's mind-boggling. 542 00:19:07,480 --> 00:19:09,020 It's like these black holes are rewriting 543 00:19:09,020 --> 00:19:10,020 the rules of the universe. 544 00:19:10,020 --> 00:19:12,160 They're definitely making us rethink things. 545 00:19:12,160 --> 00:19:15,120 And they're also really putting Einstein's theory 546 00:19:15,120 --> 00:19:17,160 of general relativity to the test. 547 00:19:17,160 --> 00:19:19,960 But hasn't Einstein's theory been pretty successful so far? 548 00:19:19,960 --> 00:19:21,480 Oh, incredibly successful. 549 00:19:21,480 --> 00:19:25,280 It's predicted tons of phenomena with amazing accuracy. 550 00:19:25,280 --> 00:19:27,400 But black holes, they represent some 551 00:19:27,400 --> 00:19:29,840 of the most extreme conditions in the universe. 552 00:19:29,840 --> 00:19:32,880 And we're not entirely sure if general relativity holds up 553 00:19:32,880 --> 00:19:34,680 perfectly in those situations. 554 00:19:34,680 --> 00:19:36,040 So black holes could be showing us 555 00:19:36,040 --> 00:19:38,200 like cracks in Einstein's masterpiece. 556 00:19:38,200 --> 00:19:39,400 It's a possibility. 557 00:19:39,400 --> 00:19:41,080 There might be some small differences 558 00:19:41,080 --> 00:19:43,600 from general relativity in those super strong 559 00:19:43,600 --> 00:19:46,000 gravitational fields near black holes. 560 00:19:46,000 --> 00:19:48,840 And if we can find those differences, well, 561 00:19:48,840 --> 00:19:52,020 it could lead us to a whole new, more complete theory 562 00:19:52,020 --> 00:19:52,800 of gravity. 563 00:19:52,800 --> 00:19:55,240 That would be like a game changer. 564 00:19:55,240 --> 00:19:56,120 It would be huge. 565 00:19:56,120 --> 00:19:58,480 It would change how we understand how the universe works 566 00:19:58,480 --> 00:19:59,920 at a fundamental level. 567 00:19:59,920 --> 00:20:03,440 So these black holes are like cosmic laboratories, 568 00:20:03,440 --> 00:20:05,760 letting us explore the boundaries of physics. 569 00:20:05,760 --> 00:20:07,480 That's a great way to think about it. 570 00:20:07,480 --> 00:20:10,400 And they're also making us ask some really big philosophical 571 00:20:10,400 --> 00:20:12,800 questions about the nature of reality, 572 00:20:12,800 --> 00:20:15,620 about information, and about the limits of what 573 00:20:15,620 --> 00:20:17,280 we can even know. 574 00:20:17,280 --> 00:20:19,920 It's fascinating that something that seems so destructive 575 00:20:19,920 --> 00:20:21,800 could also teach us so much. 576 00:20:21,800 --> 00:20:23,720 That's the thing about black holes, isn't it? 577 00:20:23,720 --> 00:20:26,880 They're both terrifying and awesome at the same time. 578 00:20:26,880 --> 00:20:28,600 They inspire both fear and wonder. 579 00:20:28,600 --> 00:20:30,880 And I think that's what makes them so captivating to so 580 00:20:30,880 --> 00:20:31,640 many people, right? 581 00:20:31,640 --> 00:20:34,160 They're just so mysterious and powerful. 582 00:20:34,160 --> 00:20:36,040 They really grab your imagination. 583 00:20:36,040 --> 00:20:37,120 Couldn't agree more. 584 00:20:37,120 --> 00:20:39,080 And as we continue to study them, 585 00:20:39,080 --> 00:20:41,840 I'm sure they'll keep challenging us, inspiring us, 586 00:20:41,840 --> 00:20:44,840 and amazing us for a long, long time. 587 00:20:44,840 --> 00:20:47,100 This whole deep dive has been incredible. 588 00:20:47,100 --> 00:20:51,360 I feel like I've learned so much about supermassive black holes, 589 00:20:51,360 --> 00:20:54,760 how they form, how they affect galaxies, 590 00:20:54,760 --> 00:20:57,360 the mysteries we're still trying to solve, 591 00:20:57,360 --> 00:20:59,400 and how they're pushing the boundaries of physics 592 00:20:59,400 --> 00:21:01,520 and our whole understanding of the universe. 593 00:21:01,520 --> 00:21:03,080 It's been a fantastic journey. 594 00:21:03,080 --> 00:21:05,840 And it's been great exploring these cosmic wonders with you. 595 00:21:05,840 --> 00:21:08,840 I hope our listeners are feeling just as inspired and fascinated 596 00:21:08,840 --> 00:21:09,600 as we are. 597 00:21:09,600 --> 00:21:10,720 I'm sure they are. 598 00:21:10,720 --> 00:21:13,560 And if you want to keep exploring the universe with us, 599 00:21:13,560 --> 00:21:17,080 be sure to follow Cosmos in a pod on your favorite podcast 600 00:21:17,080 --> 00:21:17,600 app. 601 00:21:17,600 --> 00:21:19,720 And don't forget to check out our YouTube channel 602 00:21:19,720 --> 00:21:22,080 for even more mind-blowing space content. 603 00:21:22,080 --> 00:21:24,680 We've got stunning visuals, animations, 604 00:21:24,680 --> 00:21:26,580 all sorts of stuff that will really 605 00:21:26,580 --> 00:21:28,200 bring these concepts to life. 606 00:21:28,200 --> 00:21:29,320 That's it for today, folks. 607 00:21:29,320 --> 00:21:31,600 Until next time, keep looking up and keep 608 00:21:31,600 --> 00:21:41,280 those cosmic questions coming.