1 00:00:08,440 --> 00:00:10,520 Speaker 1: Hey, Daniel, I have a question for you about how 2 00:00:10,760 --> 00:00:14,800 Speaker 1: big things are. Is this a question about my pandemic 3 00:00:14,920 --> 00:00:18,160 Speaker 1: snacking habit? No, No, I'm wondering. How do you think 4 00:00:18,160 --> 00:00:21,040 Speaker 1: about the massive size of things? Like there are so 5 00:00:21,079 --> 00:00:23,239 Speaker 1: many big things out during the universe. I know you mean, 6 00:00:23,280 --> 00:00:26,279 Speaker 1: like how the sun is a million times bigger than 7 00:00:26,280 --> 00:00:28,400 Speaker 1: our earth. Yeah, I'm wondering there are things out there 8 00:00:28,400 --> 00:00:31,400 Speaker 1: there are even millions or billions of times bigger than 9 00:00:31,440 --> 00:00:33,760 Speaker 1: our sun. Yeah, you know, some things out there are 10 00:00:33,880 --> 00:00:37,839 Speaker 1: incredibly massive. Maybe they've been doing some pandemic snacking of 11 00:00:37,880 --> 00:00:40,920 Speaker 1: their own. You mean, like eating whole stars between meals. 12 00:00:41,760 --> 00:00:44,920 Speaker 1: I wouldn't recommend it, just three stars per day? Is 13 00:00:44,960 --> 00:01:03,319 Speaker 1: there a doctor's recommendation? Yes, we are doctors. I am 14 00:01:03,320 --> 00:01:07,200 Speaker 1: forhanda cartoonists and the creator of PhD comics. Hi, I'm Daniel. 15 00:01:07,280 --> 00:01:10,240 Speaker 1: I'm a particle physicist and technically i'm a doctor. But 16 00:01:10,400 --> 00:01:14,080 Speaker 1: please don't follow my medical advice. Yes, physicists don't make 17 00:01:14,160 --> 00:01:18,360 Speaker 1: the best lifestyle examples. No, that's true, and particle physics 18 00:01:18,560 --> 00:01:22,000 Speaker 1: especially is not a very practical degree. You can't collide 19 00:01:22,000 --> 00:01:24,600 Speaker 1: the germs in your body. Oh that sounds like fun. Actually, 20 00:01:24,640 --> 00:01:27,959 Speaker 1: I'm going to write that proposal. I think most people 21 00:01:27,959 --> 00:01:30,440 Speaker 1: would love to collide a certain virus right now in 22 00:01:30,480 --> 00:01:33,040 Speaker 1: your super collider. But welcome to our podcast. Daniel and 23 00:01:33,080 --> 00:01:36,160 Speaker 1: Jorge explain the university production of I Heart Radio, in 24 00:01:36,160 --> 00:01:39,280 Speaker 1: which we explore all the crazy and amazing things in 25 00:01:39,319 --> 00:01:42,560 Speaker 1: the universe colliding them with your brain, from the very 26 00:01:42,600 --> 00:01:45,759 Speaker 1: smallest particles to the weird stuff happening on our scale, 27 00:01:45,959 --> 00:01:48,960 Speaker 1: to the very big, the very enormous, the very super 28 00:01:49,080 --> 00:01:52,520 Speaker 1: duper mysteries of the universe. Yeah, the biggest mysteries out 29 00:01:52,560 --> 00:01:55,840 Speaker 1: there and also the most massive mysteries. Because Massa's is 30 00:01:55,920 --> 00:01:57,720 Speaker 1: such a fun thing to think about. You know, it 31 00:01:57,760 --> 00:01:59,960 Speaker 1: makes stuff stuff if you think about it. I don't 32 00:02:00,000 --> 00:02:03,440 Speaker 1: like to think about my mass very much. Actually, actually, 33 00:02:03,440 --> 00:02:05,840 Speaker 1: I'm getting pretty fit in this pandemic. I've been doing 34 00:02:06,520 --> 00:02:10,280 Speaker 1: more exercise and normal to say that I'm getting some exercise. 35 00:02:11,960 --> 00:02:15,440 Speaker 1: But mass is incredible because on one hand, there's so 36 00:02:15,520 --> 00:02:18,160 Speaker 1: much space out there that's just empty, like most of 37 00:02:18,200 --> 00:02:21,399 Speaker 1: the universe is just emptiness. But then there are these 38 00:02:21,440 --> 00:02:25,920 Speaker 1: incredible clumps of amazing density, these blobs of stuff. They 39 00:02:25,960 --> 00:02:28,560 Speaker 1: know the size of a planet, the size of Jupiter, 40 00:02:28,720 --> 00:02:31,880 Speaker 1: the size of the Sun, and then even monstrously bigger 41 00:02:31,919 --> 00:02:34,080 Speaker 1: than that. Yeah, because there are things out there that 42 00:02:34,120 --> 00:02:37,160 Speaker 1: are so massive and so dense that they actually turn 43 00:02:37,240 --> 00:02:40,359 Speaker 1: into black holes. And you know, black holes, I think 44 00:02:40,360 --> 00:02:42,519 Speaker 1: we people tend to think of them as one thing, 45 00:02:42,680 --> 00:02:44,760 Speaker 1: like once you become a black hole, that's it. You're 46 00:02:44,800 --> 00:02:47,200 Speaker 1: a black hole. But actually there's a big variety of 47 00:02:47,240 --> 00:02:49,360 Speaker 1: black holes out there in the universe, that's right. Black 48 00:02:49,400 --> 00:02:52,400 Speaker 1: Holes come in all shapes and sizes. Some of them spin, 49 00:02:52,560 --> 00:02:54,720 Speaker 1: some of them have electric charge, Some of them are 50 00:02:54,800 --> 00:02:58,959 Speaker 1: quite small, some of them are incredibly super duper huge. 51 00:02:59,120 --> 00:03:00,880 Speaker 1: They come in different ship apes. Can they come in 52 00:03:00,880 --> 00:03:03,240 Speaker 1: different shapes depending on the stuff around them, So it 53 00:03:03,280 --> 00:03:05,440 Speaker 1: depends on what you call part of the black hole. 54 00:03:05,639 --> 00:03:08,080 Speaker 1: They're mostly spears, but some of them have disks of 55 00:03:08,120 --> 00:03:10,000 Speaker 1: stuff around them that are bigger and smaller. Some of 56 00:03:10,040 --> 00:03:12,399 Speaker 1: them are on their own, and so I guess maybe 57 00:03:12,400 --> 00:03:14,680 Speaker 1: they don't have different shapes, they have different clothing, They're 58 00:03:14,760 --> 00:03:19,800 Speaker 1: dressed differently. Can you have like a banana shade black hole? Probably? 59 00:03:20,000 --> 00:03:22,239 Speaker 1: You know, you get a decretion disc with stuff is 60 00:03:22,280 --> 00:03:24,240 Speaker 1: swirled only on one side that would look a lot 61 00:03:24,240 --> 00:03:26,359 Speaker 1: like a banana. So I'm gonna go with yes. It's 62 00:03:26,400 --> 00:03:30,399 Speaker 1: likely that out there somewhere there's a huge gas banana 63 00:03:30,600 --> 00:03:33,440 Speaker 1: getting sucked into a black hole. Official word here, ladies 64 00:03:33,440 --> 00:03:36,680 Speaker 1: and gentlemen from your doctor. That's right. And so, yeah, 65 00:03:36,680 --> 00:03:39,880 Speaker 1: some of these black holes can be really, really, really heavy. 66 00:03:39,920 --> 00:03:42,720 Speaker 1: Some of them are millions of times more massive than 67 00:03:42,760 --> 00:03:45,840 Speaker 1: our sun, which is crazy to imagine. Like imagine a 68 00:03:45,920 --> 00:03:49,960 Speaker 1: million sons crowned into one place, I know. And when 69 00:03:49,960 --> 00:03:53,280 Speaker 1: you think a million sons, you instantly think something that's 70 00:03:53,360 --> 00:03:55,920 Speaker 1: super duper bright, right, But of course a black hole 71 00:03:56,000 --> 00:03:59,560 Speaker 1: is not that bright. It's huge, it's massive, but it's 72 00:03:59,560 --> 00:04:02,120 Speaker 1: not actually that bright. Right. All that mass works together 73 00:04:02,240 --> 00:04:06,120 Speaker 1: to create this strange fold in space where space becomes 74 00:04:06,120 --> 00:04:09,200 Speaker 1: like one directional. It's like a one directional portal in 75 00:04:09,280 --> 00:04:11,440 Speaker 1: space where once you go in it, you can't come out. 76 00:04:11,480 --> 00:04:13,839 Speaker 1: It doesn't matter how fast you're moving, if you're a 77 00:04:13,880 --> 00:04:17,320 Speaker 1: massless photon or a very very fast neutrino or a 78 00:04:17,360 --> 00:04:20,120 Speaker 1: blob of stuff, there's just no way out. It's not 79 00:04:20,200 --> 00:04:22,960 Speaker 1: about your speed or about your energy, it's just space 80 00:04:23,000 --> 00:04:25,760 Speaker 1: has become folded in this bizarre way, right, And so 81 00:04:25,800 --> 00:04:28,159 Speaker 1: they're one of the most amazing mysteries of physics. Yeah, 82 00:04:28,200 --> 00:04:30,560 Speaker 1: it's like one direction. The boy band also a black 83 00:04:30,560 --> 00:04:33,520 Speaker 1: hole in music. I think that was a career black hole. 84 00:04:33,680 --> 00:04:37,520 Speaker 1: But yeah, Harry Styles somehow managed to escape that that 85 00:04:37,600 --> 00:04:40,280 Speaker 1: black hole. But but yeah, but that's that's like an 86 00:04:40,320 --> 00:04:43,520 Speaker 1: average black hole. Like a black hole that's millions of 87 00:04:43,560 --> 00:04:45,960 Speaker 1: times more massive than our sun. That's like a small 88 00:04:45,960 --> 00:04:48,480 Speaker 1: black hole that doesn't impress you. I mean, it's impressive 89 00:04:48,520 --> 00:04:51,839 Speaker 1: to me, but sure the universe can impress me even more. 90 00:04:52,279 --> 00:04:55,080 Speaker 1: That's right. And the incredible thing about these black holes 91 00:04:55,200 --> 00:04:57,800 Speaker 1: is that they have to form, right, You've got to 92 00:04:57,920 --> 00:05:00,839 Speaker 1: make them. They gotta somehow get that big by gobbling 93 00:05:00,880 --> 00:05:03,320 Speaker 1: stuff up. And there are black holes that are so 94 00:05:03,400 --> 00:05:07,080 Speaker 1: big out there that scientists don't really know how they 95 00:05:07,120 --> 00:05:09,640 Speaker 1: got that big. Yeah, there are black holes out there. 96 00:05:09,640 --> 00:05:13,280 Speaker 1: There are billions of times more massive than the sun. Right, 97 00:05:13,360 --> 00:05:15,880 Speaker 1: Like we take our sun and get a million of 98 00:05:15,920 --> 00:05:18,720 Speaker 1: them together, get a thousand of those together. That's like 99 00:05:18,760 --> 00:05:22,000 Speaker 1: a that's a super massive black hole. That's really pretty impressive. 100 00:05:22,040 --> 00:05:24,000 Speaker 1: I mean, I think that that should be called super 101 00:05:24,080 --> 00:05:26,960 Speaker 1: duper massive black hole, not just supermassive. And that's actually 102 00:05:27,040 --> 00:05:29,640 Speaker 1: the official name for them, right, isn't it? Super Massive 103 00:05:29,640 --> 00:05:32,440 Speaker 1: black holes like supermassive black holes is the official name 104 00:05:32,560 --> 00:05:35,160 Speaker 1: used by actual black hole scientists. I like to call 105 00:05:35,200 --> 00:05:38,479 Speaker 1: them super duper massive because it just conveys better how 106 00:05:38,520 --> 00:05:41,960 Speaker 1: impressive they really are. Super duper mega awesome black holes, 107 00:05:42,600 --> 00:05:47,120 Speaker 1: califragilistic black holes. Can't run out of enough superlatives. Alright, 108 00:05:47,240 --> 00:05:51,360 Speaker 1: So these giant supermassive black holes, they're really big and 109 00:05:51,480 --> 00:05:54,840 Speaker 1: nobody seems to know how they get formed. So to 110 00:05:54,920 --> 00:06:01,680 Speaker 1: be on the podcast, we'll be asking the question, how 111 00:06:01,680 --> 00:06:05,240 Speaker 1: do super massive black holes get so big? I mean, 112 00:06:05,360 --> 00:06:07,839 Speaker 1: do they even lift? Man? Did they go to the gym? Like, 113 00:06:07,880 --> 00:06:11,200 Speaker 1: how did they get so big? What? What? What did 114 00:06:11,200 --> 00:06:13,920 Speaker 1: they do for the core? Exactly? Don't skip leg day 115 00:06:13,960 --> 00:06:16,400 Speaker 1: black holes. You know, it's not all about being ripped. 116 00:06:16,440 --> 00:06:19,720 Speaker 1: Are they doing the t X something something? I bet 117 00:06:19,720 --> 00:06:21,640 Speaker 1: they're doing something more holistic, right, you know, they've got 118 00:06:21,640 --> 00:06:24,640 Speaker 1: that nice, perfectly spherical shape of the event horizon, so 119 00:06:24,880 --> 00:06:26,880 Speaker 1: it's definitely some core strength. I bet there's a lot 120 00:06:26,920 --> 00:06:30,000 Speaker 1: of yoga, downward dog and all that stuff. Yeah, so 121 00:06:30,040 --> 00:06:34,119 Speaker 1: they're super duper massive and really big and people don't 122 00:06:34,120 --> 00:06:36,040 Speaker 1: know how they got that big. But we were wondering 123 00:06:36,040 --> 00:06:39,839 Speaker 1: how many of our listeners out there know or think 124 00:06:39,880 --> 00:06:42,400 Speaker 1: about how these black holes get so big. That's right, 125 00:06:42,440 --> 00:06:45,400 Speaker 1: because they are really pretty incredibly big, and it's hard 126 00:06:45,440 --> 00:06:47,719 Speaker 1: to make a black hole that big in the short 127 00:06:47,720 --> 00:06:50,480 Speaker 1: amount of time we've had in our universe. So I 128 00:06:50,520 --> 00:06:53,520 Speaker 1: sent this question to our friendly volunteers. Thank you to 129 00:06:53,600 --> 00:06:56,720 Speaker 1: everybody who signed up to answer random questions, and if 130 00:06:56,760 --> 00:07:00,080 Speaker 1: you like to participates for future episodes, please they're u 131 00:07:00,080 --> 00:07:02,920 Speaker 1: with a line to questions at Daniel and Jorge dot com. 132 00:07:03,120 --> 00:07:04,920 Speaker 1: Before you listen to these answers, think about it for 133 00:07:04,960 --> 00:07:09,080 Speaker 1: a second. If someone ask you how does supermassive black 134 00:07:09,120 --> 00:07:12,840 Speaker 1: holes get so supermassive? What would you answer? Here's what 135 00:07:12,920 --> 00:07:15,080 Speaker 1: people had to say. My guess is that black holes 136 00:07:15,160 --> 00:07:21,600 Speaker 1: become super massive by simply absorbing neighboring planets, stars, gas, 137 00:07:21,840 --> 00:07:27,320 Speaker 1: any other type of matter nearby the black hole. When 138 00:07:27,320 --> 00:07:30,160 Speaker 1: it comes into existence, it has to be large enough 139 00:07:30,240 --> 00:07:35,360 Speaker 1: where it doesn't just evaporate due to hawking radiation, and 140 00:07:35,400 --> 00:07:40,240 Speaker 1: it needs to be close enough to other sources of 141 00:07:40,480 --> 00:07:44,880 Speaker 1: matter so that it can pull them in and gain 142 00:07:45,400 --> 00:07:48,800 Speaker 1: their mass to become supermassive. The obvious answer would be 143 00:07:48,840 --> 00:07:52,560 Speaker 1: that just by you know, gobbling up nearby stuff. So 144 00:07:52,600 --> 00:07:56,880 Speaker 1: I think that all the supermassive blig holes are originating 145 00:07:56,960 --> 00:07:59,400 Speaker 1: from the early stages of the universe when it was 146 00:07:59,480 --> 00:08:02,760 Speaker 1: much then, and I think it was just easier for 147 00:08:03,080 --> 00:08:07,960 Speaker 1: existing black holes to eat up the surrounding planets or 148 00:08:08,320 --> 00:08:12,960 Speaker 1: other stars. If they start one size and gain more material, 149 00:08:13,640 --> 00:08:17,680 Speaker 1: it makes sense that they would grow. The event horizon 150 00:08:17,720 --> 00:08:21,560 Speaker 1: would grow. Certainly the more mass is in it, probably 151 00:08:21,680 --> 00:08:27,160 Speaker 1: number one would be merging with another or more black holes. 152 00:08:27,600 --> 00:08:31,400 Speaker 1: Black holes get to be super massive by emerging with 153 00:08:31,520 --> 00:08:36,520 Speaker 1: other black holes, such as when two galaxies flide and 154 00:08:36,600 --> 00:08:41,040 Speaker 1: their central black holes merge. Maybe by you know, as 155 00:08:41,040 --> 00:08:43,960 Speaker 1: they keep absorbing more matter into it. All right, so 156 00:08:44,080 --> 00:08:46,760 Speaker 1: some pretty good answers there somewhere are like, wow, I 157 00:08:46,800 --> 00:08:49,559 Speaker 1: didn't know that they does seem really possible. Yeah, the 158 00:08:49,600 --> 00:08:52,040 Speaker 1: general sense seems to be like, well, black holes get 159 00:08:52,080 --> 00:08:54,960 Speaker 1: bigger by eating stuff. So you want to get supermassive, 160 00:08:55,040 --> 00:08:57,280 Speaker 1: you gotta eat a supermassive amount of stuff. That's what 161 00:08:57,320 --> 00:09:00,319 Speaker 1: black holes do, right. They can't do anything else. They 162 00:09:00,320 --> 00:09:02,280 Speaker 1: can only consume, you know. It's not like they can 163 00:09:02,720 --> 00:09:05,000 Speaker 1: poop stuff out or anything. And it's like that's all 164 00:09:05,120 --> 00:09:07,359 Speaker 1: that's all they were intended to do by the universes 165 00:09:07,520 --> 00:09:09,280 Speaker 1: is sucks stuff? It is that not enough for you? 166 00:09:09,360 --> 00:09:13,240 Speaker 1: Like incredible folds in space gobbling up matter and incredible rates, 167 00:09:13,320 --> 00:09:16,319 Speaker 1: and you're like, what else do you got I'm saying. 168 00:09:16,480 --> 00:09:19,200 Speaker 1: I'm saying they have a limited range of skills there, 169 00:09:19,760 --> 00:09:21,920 Speaker 1: but you know, they're a niche player. They're the best 170 00:09:21,960 --> 00:09:23,800 Speaker 1: in the universe at what they do. And I think 171 00:09:23,960 --> 00:09:26,040 Speaker 1: in terms that we're talking careers here, that's really the 172 00:09:26,120 --> 00:09:29,360 Speaker 1: right way to go, right, stick to your niche, that's right. 173 00:09:30,000 --> 00:09:32,200 Speaker 1: But I think the thing that's missing from these answers 174 00:09:32,520 --> 00:09:34,920 Speaker 1: is an understanding of how you can get so big 175 00:09:35,000 --> 00:09:38,000 Speaker 1: in the limited time we've had in our universe. Like, yeah, 176 00:09:38,040 --> 00:09:41,000 Speaker 1: the universe is fourteen billion years old, but these black 177 00:09:41,000 --> 00:09:44,160 Speaker 1: holes are so big that we don't understand how they 178 00:09:44,240 --> 00:09:47,160 Speaker 1: got so big in that amount of time. Wow, that's weird. 179 00:09:47,200 --> 00:09:49,360 Speaker 1: It's weird that we can't explain that, Like that, we 180 00:09:49,480 --> 00:09:52,880 Speaker 1: have these things in the universe that are not small, 181 00:09:53,200 --> 00:09:56,240 Speaker 1: they're big and significant, like they're helping to hold the 182 00:09:56,280 --> 00:09:59,040 Speaker 1: galaxies together, right, and we don't know how they got 183 00:09:59,080 --> 00:10:01,040 Speaker 1: to how they are. But this is a really important 184 00:10:01,080 --> 00:10:02,760 Speaker 1: part of how we do science. We look at the 185 00:10:02,760 --> 00:10:04,560 Speaker 1: stuff that's out there in the universe, and we say, 186 00:10:04,760 --> 00:10:06,640 Speaker 1: do we understand how it got here? We have a 187 00:10:06,679 --> 00:10:08,960 Speaker 1: model of the early universe. We think we know the 188 00:10:09,040 --> 00:10:11,760 Speaker 1: laws that determine how things interact and how things grow 189 00:10:11,840 --> 00:10:14,160 Speaker 1: and change. So we should be able to then look 190 00:10:14,200 --> 00:10:16,880 Speaker 1: around and describe basically what we see. So if there's 191 00:10:16,920 --> 00:10:19,400 Speaker 1: something out there that we can't explain that we don't 192 00:10:19,400 --> 00:10:21,720 Speaker 1: think should be there, it tells us there must be 193 00:10:21,760 --> 00:10:24,720 Speaker 1: something wrong in our understanding, either of the initial conditions 194 00:10:24,720 --> 00:10:27,880 Speaker 1: how things started or of the rules for how things change. 195 00:10:28,000 --> 00:10:30,120 Speaker 1: All right, so let's jump right into it. Daniel and 196 00:10:30,280 --> 00:10:32,359 Speaker 1: I think we can assume that most of our listeners 197 00:10:32,720 --> 00:10:35,640 Speaker 1: know what a black hole is, which is an accumulation 198 00:10:35,720 --> 00:10:37,720 Speaker 1: of a mass so intense that it creates like a 199 00:10:37,840 --> 00:10:40,040 Speaker 1: pocket or a hole in the universe out of which 200 00:10:40,120 --> 00:10:43,560 Speaker 1: nothing can escape. I think we can assume most people 201 00:10:43,679 --> 00:10:46,200 Speaker 1: know that, But maybe what people don't know is kind 202 00:10:46,200 --> 00:10:48,720 Speaker 1: of how big or what how they can vary in size. 203 00:10:48,720 --> 00:10:51,000 Speaker 1: So step us through, like, what's a normal black hole? 204 00:10:51,120 --> 00:10:53,040 Speaker 1: So a normal black hole is the kind that you 205 00:10:53,120 --> 00:10:55,520 Speaker 1: might be familiar with that comes when a star dies. 206 00:10:56,280 --> 00:10:59,079 Speaker 1: Stars this big blob of gas, and it's a balance 207 00:10:59,120 --> 00:11:03,000 Speaker 1: between the graph compressing it and the energy released from 208 00:11:03,000 --> 00:11:05,800 Speaker 1: the fusion and the burning, and when the burning stops, 209 00:11:05,840 --> 00:11:08,480 Speaker 1: then the star collapses because all that's left is gravity, 210 00:11:08,679 --> 00:11:10,800 Speaker 1: and sometimes it collapses so much that you get a 211 00:11:10,800 --> 00:11:13,840 Speaker 1: black hole. And these black holes tend to be around 212 00:11:13,840 --> 00:11:16,160 Speaker 1: the size of the masses of stars because they were 213 00:11:16,160 --> 00:11:20,120 Speaker 1: made by one star. And so the units are usually 214 00:11:20,360 --> 00:11:22,600 Speaker 1: the mass of our Sun because it's a convenient thing. 215 00:11:22,800 --> 00:11:25,120 Speaker 1: It's not like the official star or the universe, but 216 00:11:25,160 --> 00:11:28,160 Speaker 1: it's the one we use to measure the masses of things. 217 00:11:28,280 --> 00:11:31,480 Speaker 1: And so the typical range of a stellar black hole 218 00:11:31,520 --> 00:11:35,000 Speaker 1: when they came from a star is a few times 219 00:11:35,040 --> 00:11:37,200 Speaker 1: the mass of our Sun, you know, like a few 220 00:11:37,360 --> 00:11:40,200 Speaker 1: up to maybe ten twenty. The biggest one we've seen 221 00:11:40,240 --> 00:11:43,079 Speaker 1: in this category is like, you know, seventy or eighty 222 00:11:43,080 --> 00:11:45,200 Speaker 1: times the mass of our Sun, because they come from 223 00:11:45,240 --> 00:11:48,680 Speaker 1: when the stars go supernova, right, and that's kind of 224 00:11:48,679 --> 00:11:51,440 Speaker 1: the only way they can form from stars, right, that's right, 225 00:11:51,480 --> 00:11:54,720 Speaker 1: you have a gravitational collapse, the burning stops, everything collapses 226 00:11:54,720 --> 00:11:57,439 Speaker 1: in then you sometimes get a supernova that blows out 227 00:11:57,440 --> 00:11:59,640 Speaker 1: a huge amount of material and then what's left to 228 00:11:59,679 --> 00:12:01,800 Speaker 1: the core or is a black hole. And so you 229 00:12:01,840 --> 00:12:04,480 Speaker 1: don't always get all of the stuff from the star 230 00:12:04,559 --> 00:12:07,440 Speaker 1: into the black hole. Right, You lose some stuff, it burned, 231 00:12:07,480 --> 00:12:09,480 Speaker 1: it got sent away, there was radiation, there was a 232 00:12:09,520 --> 00:12:12,480 Speaker 1: supernova blew some of that gas out into the universe. 233 00:12:12,760 --> 00:12:14,800 Speaker 1: But at the core you get that black hole. So 234 00:12:14,880 --> 00:12:17,760 Speaker 1: some fraction of the mass of the star turns into 235 00:12:17,760 --> 00:12:20,040 Speaker 1: the black hole. So for black holes that come from 236 00:12:20,080 --> 00:12:22,080 Speaker 1: a star, the mass of the black hole is a 237 00:12:22,080 --> 00:12:24,480 Speaker 1: little bit less than the mass of the original star, right, 238 00:12:24,520 --> 00:12:27,160 Speaker 1: and those stars can be as big as seventy or 239 00:12:27,240 --> 00:12:29,559 Speaker 1: eighty times the size of our sun. Yeah, there are 240 00:12:29,600 --> 00:12:32,679 Speaker 1: stars out there that are much more massive than our star, 241 00:12:33,120 --> 00:12:34,320 Speaker 1: and so they can be you know, up to a 242 00:12:34,360 --> 00:12:36,560 Speaker 1: hundred times the mass of our star, which leads to 243 00:12:36,600 --> 00:12:38,840 Speaker 1: black holes up to like, you know, eighty times the 244 00:12:38,880 --> 00:12:41,320 Speaker 1: mass of our sun. All right, So those are the 245 00:12:41,480 --> 00:12:45,240 Speaker 1: kind of the regular black holes because they form from stars, 246 00:12:45,280 --> 00:12:47,920 Speaker 1: and there are a lot of stars out there in 247 00:12:47,960 --> 00:12:49,720 Speaker 1: the universe, and those can get pretty big. I mean, 248 00:12:49,720 --> 00:12:51,920 Speaker 1: eighty times the size of our sun. That's not nothing, 249 00:12:52,120 --> 00:12:54,720 Speaker 1: that's nothing to scoff at. You know, there's eighty million 250 00:12:54,920 --> 00:12:59,240 Speaker 1: earths all packed into a tiny little blob. It's pretty impressive. 251 00:12:59,520 --> 00:13:02,120 Speaker 1: But the incredible thing about the universe is that every 252 00:13:02,120 --> 00:13:04,720 Speaker 1: time you turn around, there's something that dwarfs what you 253 00:13:04,760 --> 00:13:07,560 Speaker 1: were previously impressed by. Like why you thought the Earth 254 00:13:07,679 --> 00:13:10,320 Speaker 1: was huge. Look at Jupiter, you thought Jubiter was big. 255 00:13:10,360 --> 00:13:12,080 Speaker 1: Look at the Sun, you thought the Sun was big. 256 00:13:12,200 --> 00:13:14,600 Speaker 1: And it just keeps going and going and going, and 257 00:13:14,640 --> 00:13:18,280 Speaker 1: there's all these different scales that each one blow your mind. 258 00:13:18,640 --> 00:13:21,560 Speaker 1: That's the experience of, you know, understanding the depths of 259 00:13:21,600 --> 00:13:24,120 Speaker 1: the scales of the And so that's one sort of 260 00:13:24,240 --> 00:13:27,720 Speaker 1: category of black holes that we see or think are 261 00:13:27,800 --> 00:13:29,920 Speaker 1: there in the universe, you know, the sort of like 262 00:13:30,559 --> 00:13:33,440 Speaker 1: one to eighty times the size of our sun. But 263 00:13:33,480 --> 00:13:36,600 Speaker 1: then there's sort of another big category of black holes, 264 00:13:36,640 --> 00:13:39,720 Speaker 1: which is kind of like way out there, much bigger. 265 00:13:39,760 --> 00:13:42,160 Speaker 1: That's right, there's not like an even distribution. It's not 266 00:13:42,200 --> 00:13:44,880 Speaker 1: like black holes start from a few solar masses and 267 00:13:44,920 --> 00:13:47,000 Speaker 1: go all the way up to millions and billions. There 268 00:13:47,040 --> 00:13:50,000 Speaker 1: are two different kinds of black holes. The ones we 269 00:13:50,080 --> 00:13:52,160 Speaker 1: just talked about that come from a star, and then 270 00:13:52,200 --> 00:13:55,400 Speaker 1: this other category of really massive black holes that are 271 00:13:55,440 --> 00:13:58,360 Speaker 1: like hundreds of thousands of times the mass of a 272 00:13:58,400 --> 00:14:02,720 Speaker 1: star up to millians and billions of times the mass 273 00:14:02,760 --> 00:14:04,880 Speaker 1: of our sun, and so these are what we call 274 00:14:05,080 --> 00:14:08,079 Speaker 1: supermassive black holes, and there's like a gap there. You 275 00:14:08,120 --> 00:14:11,080 Speaker 1: don't see any black holes that are like a thousand 276 00:14:11,120 --> 00:14:13,280 Speaker 1: times the mass of the Sun or five dred times. 277 00:14:13,280 --> 00:14:16,120 Speaker 1: There's just nothing there. It's like two distinct classes. Yeah, 278 00:14:16,200 --> 00:14:18,120 Speaker 1: and it tells you that there's like two different ways 279 00:14:18,160 --> 00:14:20,680 Speaker 1: to make black holes, are two different populations, that these 280 00:14:20,720 --> 00:14:23,200 Speaker 1: things have a lot in common, but they're also really 281 00:14:23,200 --> 00:14:25,360 Speaker 1: different and they probably have a different history. Now, are 282 00:14:25,400 --> 00:14:27,360 Speaker 1: we sure that we haven't seen any in the middle 283 00:14:27,840 --> 00:14:30,800 Speaker 1: sizes or is it that we just can't theoretically come 284 00:14:30,880 --> 00:14:32,920 Speaker 1: up with them. We have not seen any in those 285 00:14:32,960 --> 00:14:35,720 Speaker 1: middle sizes. That's right, And the problem is not that 286 00:14:35,760 --> 00:14:37,120 Speaker 1: we can't come up with them. The problem is that 287 00:14:37,160 --> 00:14:39,840 Speaker 1: we can't explain how these ones got so big. It's 288 00:14:39,880 --> 00:14:43,000 Speaker 1: easier to explain smaller black holes than the ones we 289 00:14:43,040 --> 00:14:46,200 Speaker 1: see because there's more time for to accumulate gas and 290 00:14:46,200 --> 00:14:48,720 Speaker 1: to grow. The hard thing is to explain how you've 291 00:14:48,760 --> 00:14:51,760 Speaker 1: got these really really big black holes. And these big 292 00:14:51,760 --> 00:14:53,800 Speaker 1: black holes they're not just like floating out there in 293 00:14:53,800 --> 00:14:56,200 Speaker 1: the universe or part of a galaxy the way like 294 00:14:56,240 --> 00:14:58,480 Speaker 1: a stellar black hole is from a collapse of a star. 295 00:14:58,880 --> 00:15:01,720 Speaker 1: These guys tend to be at the center of a galaxy. 296 00:15:01,880 --> 00:15:03,480 Speaker 1: That's usually we'll we see them. We don't see them 297 00:15:03,480 --> 00:15:06,000 Speaker 1: floating around on their own. We definitely do not. And 298 00:15:06,160 --> 00:15:09,200 Speaker 1: every galaxy has one, and usually exactly one. Like, you 299 00:15:09,240 --> 00:15:12,480 Speaker 1: don't have two supermassive black holes in a single galaxy. 300 00:15:12,680 --> 00:15:14,640 Speaker 1: It's like, you know, this town is only big enough 301 00:15:14,680 --> 00:15:17,960 Speaker 1: for the one of us. And that's kind of funny, 302 00:15:18,040 --> 00:15:21,040 Speaker 1: isn't it. Like you only see one in the center 303 00:15:21,080 --> 00:15:24,400 Speaker 1: of each galaxy, and most galaxies have them, that's right, 304 00:15:24,720 --> 00:15:26,400 Speaker 1: And there's a reason you only see one, and that's 305 00:15:26,400 --> 00:15:28,720 Speaker 1: because they're so big and massive. Like if you get 306 00:15:28,720 --> 00:15:31,920 Speaker 1: two galaxies that collide and that they merge, then the 307 00:15:32,000 --> 00:15:35,200 Speaker 1: two supermassive black holes at their centers will orbit each 308 00:15:35,240 --> 00:15:37,800 Speaker 1: other for a little while, but eventually they'll merge and 309 00:15:37,840 --> 00:15:40,560 Speaker 1: become one. So they can't really stay separate because they're 310 00:15:40,560 --> 00:15:43,640 Speaker 1: each so powerful and sucking in the other on like Highlander, 311 00:15:43,800 --> 00:15:47,720 Speaker 1: that can only be one, that's right. And the other 312 00:15:47,760 --> 00:15:50,280 Speaker 1: thing that to understand is these black holes are a 313 00:15:50,360 --> 00:15:52,920 Speaker 1: really big part of a galaxy. It's not just like, Okay, 314 00:15:52,920 --> 00:15:55,080 Speaker 1: you've got a big black hole, but the galaxy is 315 00:15:55,160 --> 00:15:57,840 Speaker 1: much much bigger, Like each of these black holes is 316 00:15:58,160 --> 00:16:00,920 Speaker 1: on average about one one since the mass of the 317 00:16:01,200 --> 00:16:04,960 Speaker 1: entire galaxy, which you know has like hundreds of billions 318 00:16:04,960 --> 00:16:08,200 Speaker 1: of stars, but this black hole really dwarfs any other 319 00:16:08,240 --> 00:16:11,080 Speaker 1: object in the galley. It's like probably millions of times 320 00:16:11,080 --> 00:16:14,160 Speaker 1: bigger than anything else in the galaxy. Yeah, exactly. And 321 00:16:14,240 --> 00:16:17,080 Speaker 1: so the biggest ones we've seen are billions and billions 322 00:16:17,080 --> 00:16:19,360 Speaker 1: of times the mass of the Sun. And the amazing 323 00:16:19,400 --> 00:16:21,600 Speaker 1: thing is that some of them are really really old. 324 00:16:22,200 --> 00:16:25,960 Speaker 1: Like we've seen black holes that are billions of times 325 00:16:26,040 --> 00:16:28,200 Speaker 1: the mass of the Sun and have been around since 326 00:16:28,240 --> 00:16:31,080 Speaker 1: the universe was only a billion years old. What how 327 00:16:31,080 --> 00:16:33,040 Speaker 1: do we know their age? Black holes don't have any 328 00:16:33,080 --> 00:16:38,040 Speaker 1: wrinkles or you can't ask them. It's pearl cream, man. 329 00:16:38,280 --> 00:16:40,800 Speaker 1: They just look great. Well, we see an old picture 330 00:16:40,840 --> 00:16:42,600 Speaker 1: of them, Like if we're looking at something really really 331 00:16:42,600 --> 00:16:44,880 Speaker 1: far away, we're seeing old lights. So the picture we 332 00:16:44,960 --> 00:16:47,640 Speaker 1: see of them is really old. So the short answers 333 00:16:47,680 --> 00:16:50,920 Speaker 1: we're seeing really really massive black holes very far away, 334 00:16:51,240 --> 00:16:53,840 Speaker 1: which means that they happened a long time ago because 335 00:16:53,880 --> 00:16:56,040 Speaker 1: I have an old picture because the light is taking 336 00:16:56,080 --> 00:16:58,240 Speaker 1: billions of years to get here. It's it's an old 337 00:16:58,360 --> 00:17:01,720 Speaker 1: picture and they're still there. Yes, so we know that 338 00:17:01,800 --> 00:17:05,400 Speaker 1: after only a billion years of universe formation, that were 339 00:17:05,440 --> 00:17:09,360 Speaker 1: already super massive black holes that were billions of times 340 00:17:09,400 --> 00:17:11,959 Speaker 1: the mass of our sun. Man, all right, let's get 341 00:17:12,000 --> 00:17:16,000 Speaker 1: into how we can see these black holes, and let's 342 00:17:16,000 --> 00:17:18,359 Speaker 1: get into the mystery of how they got so big. 343 00:17:18,640 --> 00:17:33,520 Speaker 1: But first let's take a quick break. All right, Daniel, 344 00:17:33,720 --> 00:17:39,320 Speaker 1: we're talking about super duper awesome, ginormous black holes, and 345 00:17:40,200 --> 00:17:42,720 Speaker 1: there's a big mystery about how they get so big, 346 00:17:42,760 --> 00:17:45,000 Speaker 1: because they're much bigger than the regular black holes that 347 00:17:45,000 --> 00:17:48,080 Speaker 1: we see floating around in space. And so I guess 348 00:17:48,119 --> 00:17:49,439 Speaker 1: the question is how do we First of all, how 349 00:17:49,440 --> 00:17:51,280 Speaker 1: do we see them? How do we see black holes? 350 00:17:51,280 --> 00:17:54,520 Speaker 1: So black holes we can never see directly, so we 351 00:17:54,560 --> 00:17:58,080 Speaker 1: have no like, really direct proof that black holes actually exist. 352 00:17:58,160 --> 00:18:01,200 Speaker 1: We just have a lot of really good circumstantial evidence, 353 00:18:01,560 --> 00:18:04,840 Speaker 1: and all of our evidence essentially is gravitational. Basically, the 354 00:18:04,960 --> 00:18:07,560 Speaker 1: argument is always there's a huge amount of mass in 355 00:18:07,600 --> 00:18:11,040 Speaker 1: a small amount of space, and nothing else can do that, 356 00:18:11,080 --> 00:18:13,160 Speaker 1: so it must be a black hole. We see nothing 357 00:18:13,200 --> 00:18:15,959 Speaker 1: else there, you know, like you can see a big 358 00:18:16,000 --> 00:18:20,520 Speaker 1: swirl of gas surrounding some black object, and that gas 359 00:18:20,680 --> 00:18:23,680 Speaker 1: is obviously under incredible pressure because it's emitting a lot 360 00:18:23,720 --> 00:18:27,439 Speaker 1: of radiation. Or you can see other stars moving around 361 00:18:27,480 --> 00:18:30,960 Speaker 1: this object in space on crazy orbits that would require 362 00:18:31,040 --> 00:18:35,639 Speaker 1: intense gravitational fields that are only consistent with an object 363 00:18:35,720 --> 00:18:39,439 Speaker 1: that's very small and very massive. And so then we conclude, okay, 364 00:18:39,480 --> 00:18:41,840 Speaker 1: there must be a black hole there, and we can 365 00:18:41,880 --> 00:18:44,600 Speaker 1: calculate its mass based on the orbits of stars around 366 00:18:45,480 --> 00:18:47,520 Speaker 1: and but those are the regular ones. The one at 367 00:18:47,560 --> 00:18:49,280 Speaker 1: the center of galaxy is the one that we know 368 00:18:49,359 --> 00:18:51,600 Speaker 1: are really old and big. How do we like, how 369 00:18:51,600 --> 00:18:54,000 Speaker 1: do we see it? Can you can you actually see 370 00:18:54,119 --> 00:18:56,679 Speaker 1: the stars going around it in a galaxy so far away? 371 00:18:56,840 --> 00:18:59,280 Speaker 1: In our galaxy, you can see the stars going around it. 372 00:18:59,400 --> 00:19:01,760 Speaker 1: Like we have looked directly at the path of stars 373 00:19:02,000 --> 00:19:04,400 Speaker 1: zipping around the black hole at the center of our galaxy, 374 00:19:04,400 --> 00:19:07,360 Speaker 1: which is called Sagittarius A. So we know that one 375 00:19:07,480 --> 00:19:10,440 Speaker 1: pretty well. In terms of other galaxies, like ones really 376 00:19:10,480 --> 00:19:13,280 Speaker 1: far away in the old early universe, we see them 377 00:19:13,320 --> 00:19:17,120 Speaker 1: because the radiation of the gas that they're squeezing around them, 378 00:19:17,320 --> 00:19:20,240 Speaker 1: So this is disc of stuff around them that's swirling around, 379 00:19:20,280 --> 00:19:23,000 Speaker 1: waiting to get sucked in and it's getting squeezed and 380 00:19:23,040 --> 00:19:26,000 Speaker 1: pulled by the tidal forces, the gravitational pressure, and so 381 00:19:26,080 --> 00:19:28,800 Speaker 1: it's emitting a huge amount of light. And those are 382 00:19:28,800 --> 00:19:32,120 Speaker 1: actually some of the brightest things in the universe. Sort 383 00:19:32,119 --> 00:19:35,600 Speaker 1: of weird, these really massive dark objects actually end up 384 00:19:35,600 --> 00:19:38,320 Speaker 1: being some of the brightest things, and they're called quasars. 385 00:19:38,720 --> 00:19:40,920 Speaker 1: That's how they were originally discovered. So we saw these 386 00:19:41,200 --> 00:19:43,600 Speaker 1: really bright objects in the sky and we didn't understand 387 00:19:43,680 --> 00:19:45,760 Speaker 1: what could be emitting so much radiation. Right, so we 388 00:19:45,800 --> 00:19:47,960 Speaker 1: can actually see them. They glow, or at least that 389 00:19:48,040 --> 00:19:49,919 Speaker 1: the stuff around them glows. Yes, then how do you 390 00:19:50,000 --> 00:19:51,960 Speaker 1: how do you tell how massive they are? Yes, so 391 00:19:52,000 --> 00:19:54,400 Speaker 1: the stuff around them glows, right. The black hole itself 392 00:19:54,520 --> 00:19:56,960 Speaker 1: is black, with the exception of Hawking radiation, which nobody 393 00:19:57,000 --> 00:19:59,439 Speaker 1: has ever seen. It emits no light, but you know, 394 00:19:59,480 --> 00:20:02,560 Speaker 1: the stuff are round that it's entourage is very very bright. 395 00:20:02,600 --> 00:20:04,960 Speaker 1: And that's how we see these really distant ones. But 396 00:20:05,040 --> 00:20:07,359 Speaker 1: you can also just watch stars move around them and 397 00:20:07,400 --> 00:20:10,240 Speaker 1: just track their path and do the calculation and say, 398 00:20:10,359 --> 00:20:12,960 Speaker 1: for this start to bend so much in space, how 399 00:20:13,040 --> 00:20:15,200 Speaker 1: much mass would there have to be in that black hole? 400 00:20:15,440 --> 00:20:17,440 Speaker 1: And that's how you can estimate their mass. It also 401 00:20:17,440 --> 00:20:19,199 Speaker 1: gives you a limit on their size, right because you 402 00:20:19,200 --> 00:20:21,960 Speaker 1: can see the star moved near the black hole, so 403 00:20:22,000 --> 00:20:24,920 Speaker 1: you know how big the black hole isn't all? Right, 404 00:20:24,960 --> 00:20:27,440 Speaker 1: So there's this whole category of black holes that are 405 00:20:27,480 --> 00:20:30,440 Speaker 1: super massive, much bigger than the regular ones that form 406 00:20:30,600 --> 00:20:34,040 Speaker 1: from supernovas. And so I guess the big mystery you 407 00:20:34,080 --> 00:20:35,719 Speaker 1: were telling me is that we don't know how they 408 00:20:35,720 --> 00:20:38,040 Speaker 1: get started or how they get so big. What does 409 00:20:38,040 --> 00:20:39,960 Speaker 1: that mean? How can we not know how black hole 410 00:20:40,080 --> 00:20:42,960 Speaker 1: gets Do they just eat or stuff? Yeah, so it's 411 00:20:42,960 --> 00:20:45,240 Speaker 1: sort of a two part mystery. Right. You need your 412 00:20:45,280 --> 00:20:47,040 Speaker 1: black hole to get big, so you just feed it 413 00:20:47,040 --> 00:20:49,760 Speaker 1: a lot, right, Well, if you start from a stellar 414 00:20:49,800 --> 00:20:52,880 Speaker 1: mass black hole, like one the size of a few suns, 415 00:20:53,200 --> 00:20:55,480 Speaker 1: then there just isn't enough time to feed that to 416 00:20:55,560 --> 00:20:57,480 Speaker 1: make it big. Why not? You want to grow a 417 00:20:57,520 --> 00:20:59,960 Speaker 1: plant in your backyard? Is a limit to how fast 418 00:21:00,000 --> 00:21:01,440 Speaker 1: as they can grow? And the same is true for 419 00:21:01,520 --> 00:21:03,959 Speaker 1: black holes. Really, why is there a limit on how 420 00:21:04,040 --> 00:21:06,320 Speaker 1: fast it can grow? Can't just sucks stuff in at 421 00:21:06,320 --> 00:21:09,119 Speaker 1: an incredible rate? There is there a limit. There is 422 00:21:09,160 --> 00:21:12,480 Speaker 1: actually a limit, And because there's a feedback, like as 423 00:21:12,520 --> 00:21:15,760 Speaker 1: the black hole gets more powerful, it starts to excite 424 00:21:15,760 --> 00:21:18,560 Speaker 1: the gas around it, which gives off a lot of radiation, 425 00:21:18,800 --> 00:21:21,239 Speaker 1: and so it actually pushes stuff away from it. So 426 00:21:21,280 --> 00:21:24,360 Speaker 1: the faster you feed a black hole, then the heavier 427 00:21:24,400 --> 00:21:26,440 Speaker 1: it gets, the more it pushes stuff away from it. 428 00:21:26,520 --> 00:21:30,000 Speaker 1: So it's really delicate balance. This is called the Eddington limit. 429 00:21:30,680 --> 00:21:32,199 Speaker 1: If you want to grow your black hole, you can 430 00:21:32,240 --> 00:21:34,120 Speaker 1: either feed it a little bit at a time right 431 00:21:34,400 --> 00:21:37,119 Speaker 1: and avoid that radiation. You dump too much stuff in it, 432 00:21:37,280 --> 00:21:39,280 Speaker 1: it's gonna blow all of the fuel away. So you've 433 00:21:39,280 --> 00:21:41,159 Speaker 1: got to find this right balance. You gotta feed it 434 00:21:41,160 --> 00:21:44,280 Speaker 1: at just the right rate to get the maximum growth curve. 435 00:21:44,400 --> 00:21:45,880 Speaker 1: Oh I see if you if you try to feed 436 00:21:45,920 --> 00:21:49,040 Speaker 1: it too fast, it's actually going to create an explosion 437 00:21:49,440 --> 00:21:51,679 Speaker 1: which is going to blow all your food away. That's right, 438 00:21:51,680 --> 00:21:54,639 Speaker 1: because remember these quasars, these the brightest things in the universe. 439 00:21:54,640 --> 00:21:57,000 Speaker 1: That's an enormous amount of radiation. So it's going to 440 00:21:57,080 --> 00:21:59,199 Speaker 1: clear out all the space near it, which is going 441 00:21:59,240 --> 00:22:01,679 Speaker 1: to prevent it for growing any further. So it's not 442 00:22:01,720 --> 00:22:04,080 Speaker 1: like a physical limitation. Is no law that says the 443 00:22:04,119 --> 00:22:06,680 Speaker 1: black hole can't grow faster. It's just a question of 444 00:22:06,800 --> 00:22:09,720 Speaker 1: like getting that stuff into the black hole while its 445 00:22:09,760 --> 00:22:12,520 Speaker 1: meanwhile pumping out a bunch of radiation. Right, But I 446 00:22:12,520 --> 00:22:16,120 Speaker 1: guess doesn't that all doesn't assume that the stuff goes 447 00:22:16,160 --> 00:22:18,280 Speaker 1: in kind of in a spiral. What is stuff just 448 00:22:18,320 --> 00:22:21,080 Speaker 1: goes in directly? Yeah, if you have really cold gas, 449 00:22:21,359 --> 00:22:23,840 Speaker 1: then it can go in, but it's got to get 450 00:22:23,880 --> 00:22:27,240 Speaker 1: past all that radiation. Remember, you're surrounded by there's always 451 00:22:27,240 --> 00:22:30,000 Speaker 1: going to be some warm gas, some stuff surrounding the 452 00:22:30,040 --> 00:22:33,000 Speaker 1: black hole that's going to radiated. So it's it's like 453 00:22:33,040 --> 00:22:36,199 Speaker 1: an environmental question. First they suck up all the cold gas, 454 00:22:36,680 --> 00:22:39,160 Speaker 1: the stuff that's not gonna swirl, but then what's left 455 00:22:39,240 --> 00:22:41,520 Speaker 1: is the hot gas, and so that takes longer to 456 00:22:41,520 --> 00:22:44,680 Speaker 1: get in, all right, So then there's a maximum rate 457 00:22:45,000 --> 00:22:47,240 Speaker 1: or speed at which you can black holes can eat. 458 00:22:47,359 --> 00:22:50,040 Speaker 1: And so the mystery said, if you take that speed 459 00:22:50,119 --> 00:22:52,320 Speaker 1: and you're multiplied by the age of the universe, that 460 00:22:52,359 --> 00:22:54,879 Speaker 1: doesn't give you enough stuff. You can't get enough stuff 461 00:22:54,920 --> 00:22:57,359 Speaker 1: into the black hole to explain how big they are. Now, 462 00:22:57,440 --> 00:22:59,639 Speaker 1: that's right. If you start from really small black holes 463 00:23:00,080 --> 00:23:02,760 Speaker 1: you go with the maximum speed of growth, you don't 464 00:23:02,880 --> 00:23:06,040 Speaker 1: get to millions and billions of masses of black holes. 465 00:23:06,119 --> 00:23:09,000 Speaker 1: They just stay too small. In our simulation, and so 466 00:23:09,080 --> 00:23:10,719 Speaker 1: you need to figure out a way to make them 467 00:23:10,720 --> 00:23:13,560 Speaker 1: grow faster, which we don't understand, or you need to 468 00:23:13,600 --> 00:23:16,719 Speaker 1: start from bigger black holes in the early universe, so 469 00:23:16,760 --> 00:23:19,160 Speaker 1: you sort of like get ahead, start right, like maybe 470 00:23:19,160 --> 00:23:22,399 Speaker 1: they started big, that's right. The major mysteries on understanding 471 00:23:22,640 --> 00:23:25,280 Speaker 1: how these black holes could have formed in the very 472 00:23:25,320 --> 00:23:28,280 Speaker 1: early universe and started out really big. So there's a 473 00:23:28,320 --> 00:23:30,280 Speaker 1: few ideas there for how you could have really big 474 00:23:30,320 --> 00:23:32,959 Speaker 1: seeds of black holes in the early universe. All right, 475 00:23:33,040 --> 00:23:35,040 Speaker 1: step us through. What are some of the different ways 476 00:23:35,080 --> 00:23:38,200 Speaker 1: in which you could start with a really big black hole. Well, 477 00:23:38,240 --> 00:23:41,119 Speaker 1: one of the ways is really theoretical and speculative and 478 00:23:41,160 --> 00:23:45,479 Speaker 1: probably wrong, but it's also really fun. You guys have 479 00:23:45,520 --> 00:23:47,560 Speaker 1: to make that call all the time. They're like, wow, 480 00:23:47,600 --> 00:23:50,760 Speaker 1: this is obviously wrong, but it sounds fun. So I'm 481 00:23:50,760 --> 00:23:52,960 Speaker 1: going to spend the next three months thinking about it. Yeah, 482 00:23:53,000 --> 00:23:54,960 Speaker 1: it's the idea that we talked about a few weeks ago. 483 00:23:54,960 --> 00:23:58,639 Speaker 1: It's called primordial black holes. That is, maybe black holes 484 00:23:58,680 --> 00:24:01,679 Speaker 1: were made not by a collapse of stars, but some 485 00:24:01,760 --> 00:24:04,160 Speaker 1: of them were made in the very early universe before 486 00:24:04,200 --> 00:24:07,520 Speaker 1: we even had matter. Like these are called primordial black 487 00:24:07,560 --> 00:24:10,879 Speaker 1: holes that were formed out of the early energy fluctuations 488 00:24:10,960 --> 00:24:14,000 Speaker 1: just after the Big Bang. You mean like that, that's 489 00:24:14,000 --> 00:24:17,120 Speaker 1: just how they form from the primordial soup of the universe. 490 00:24:17,320 --> 00:24:20,280 Speaker 1: Like they just as the universe expanded and exploded. They're 491 00:24:20,359 --> 00:24:23,520 Speaker 1: just happened to be some random, you know, blip in 492 00:24:23,520 --> 00:24:26,640 Speaker 1: the quantum fluctuations that created a big black hole. Yeah, 493 00:24:26,760 --> 00:24:29,680 Speaker 1: the pictures that you start out with this homogeneous, smooth 494 00:24:29,840 --> 00:24:33,560 Speaker 1: universe immediately after the Big Bank, then there are quantum fluctuations. 495 00:24:33,600 --> 00:24:36,480 Speaker 1: Things get a little denser here, a little less dense there, 496 00:24:36,880 --> 00:24:39,280 Speaker 1: And in places where you happen to have a really 497 00:24:39,280 --> 00:24:42,760 Speaker 1: big quantum fluctuation, you can get enough energy density to 498 00:24:42,880 --> 00:24:46,040 Speaker 1: create a black hole. Even before the universe cools enough 499 00:24:46,080 --> 00:24:48,879 Speaker 1: to make particles, and those particles turned into atoms, and 500 00:24:48,920 --> 00:24:52,119 Speaker 1: those atoms turned into gas which collect to grow stars 501 00:24:52,119 --> 00:24:55,359 Speaker 1: and eventually become black holes. You circumvent that whole process 502 00:24:55,560 --> 00:24:57,960 Speaker 1: and just make a black hole boom right from the 503 00:24:58,000 --> 00:25:00,879 Speaker 1: get go. So these are called primar real black holes, 504 00:25:01,119 --> 00:25:03,359 Speaker 1: and we have no idea if they actually exist. We 505 00:25:03,400 --> 00:25:05,880 Speaker 1: had a really fun podcast about them. But if they do, 506 00:25:05,960 --> 00:25:08,720 Speaker 1: we expect they exist from the very very small sizes 507 00:25:09,080 --> 00:25:12,440 Speaker 1: up to really enormous sizes, and so this is one 508 00:25:12,480 --> 00:25:15,880 Speaker 1: way to get black holes really big in the early universe, right, 509 00:25:15,960 --> 00:25:18,000 Speaker 1: And that may kind of makes sense to me, But 510 00:25:18,119 --> 00:25:20,040 Speaker 1: why is it so speculative and why is it such 511 00:25:20,040 --> 00:25:22,600 Speaker 1: a crazy theory? Well, nobody's ever seen one. We don't 512 00:25:22,640 --> 00:25:24,520 Speaker 1: know if they're out there. We know the black holes 513 00:25:24,520 --> 00:25:26,800 Speaker 1: are out there, we know that stars can form black holes, 514 00:25:26,840 --> 00:25:29,520 Speaker 1: we know there are supermassive black holes, but nobody's ever 515 00:25:29,600 --> 00:25:31,919 Speaker 1: seen a primordial black hole, I guess. I mean, how 516 00:25:32,000 --> 00:25:34,400 Speaker 1: how do we know that the supermassive black holes are 517 00:25:34,400 --> 00:25:37,879 Speaker 1: not primordial black holes. We don't. And it's possible that 518 00:25:37,920 --> 00:25:40,960 Speaker 1: primordial black holes are the seeds of supermassive black holes. 519 00:25:41,000 --> 00:25:43,800 Speaker 1: That would explain a lot, but it's a bit too convenient, 520 00:25:44,080 --> 00:25:46,159 Speaker 1: and the theory is is sort of weird, And we 521 00:25:46,200 --> 00:25:48,919 Speaker 1: would expect to see primordial black holes sort of at 522 00:25:48,960 --> 00:25:51,679 Speaker 1: all masses, not just really really big and not just 523 00:25:51,720 --> 00:25:54,639 Speaker 1: really really small, but also sort of in the intermediate range, 524 00:25:54,840 --> 00:25:56,320 Speaker 1: and they would be doing stuff that we should be 525 00:25:56,359 --> 00:25:58,720 Speaker 1: able to see, like sometimes they would pass through a 526 00:25:58,840 --> 00:26:02,520 Speaker 1: star and cause disturbances on its surface, or sometimes if 527 00:26:02,520 --> 00:26:05,680 Speaker 1: they were really small, they would decay with hawking radiation 528 00:26:05,920 --> 00:26:08,320 Speaker 1: in these bright flashes of light at the edge of galaxies, 529 00:26:08,560 --> 00:26:11,440 Speaker 1: we would expect to see some primordial black holes if 530 00:26:11,440 --> 00:26:13,679 Speaker 1: they had been around them. We've never seen one, so 531 00:26:13,720 --> 00:26:17,040 Speaker 1: that makes it a bit awkward. I see, if these 532 00:26:17,080 --> 00:26:19,600 Speaker 1: came from primordial black holes, we would expect to see 533 00:26:19,720 --> 00:26:22,439 Speaker 1: more of these primordial black holes floating around, don't But 534 00:26:22,520 --> 00:26:25,359 Speaker 1: we don't. So maybe only primordial black holes were made 535 00:26:25,400 --> 00:26:27,800 Speaker 1: on the larger sizes, which is a little bit awkward 536 00:26:27,840 --> 00:26:30,520 Speaker 1: cosmologically to like come up with a model that only 537 00:26:30,560 --> 00:26:33,400 Speaker 1: makes really really big primordial black holes, So it gets 538 00:26:33,480 --> 00:26:35,320 Speaker 1: less and less attractive as an option the more you 539 00:26:35,359 --> 00:26:37,600 Speaker 1: have to like tweak it and cram it into this box. 540 00:26:37,600 --> 00:26:40,800 Speaker 1: All right, So then what's another possible reason that we 541 00:26:40,840 --> 00:26:43,399 Speaker 1: have these massive black holes. Well, it could be that 542 00:26:43,480 --> 00:26:46,439 Speaker 1: in the very early universe, stars were much bigger than 543 00:26:46,480 --> 00:26:49,160 Speaker 1: they are today. So you could have had like horses, 544 00:26:50,680 --> 00:26:53,400 Speaker 1: like courses used to be ginormals the size of a bus. Yeah, 545 00:26:53,560 --> 00:26:55,840 Speaker 1: horses used to be three hundred times the mass of 546 00:26:55,880 --> 00:27:01,200 Speaker 1: the sun. It turns out it's a big horse, of course. No, 547 00:27:01,359 --> 00:27:04,240 Speaker 1: So these days stars are you know, range up to 548 00:27:04,680 --> 00:27:06,560 Speaker 1: you know, maybe a hundred times the mass of the Sun. 549 00:27:06,800 --> 00:27:09,600 Speaker 1: But it could be that the very early universe stars 550 00:27:09,640 --> 00:27:12,640 Speaker 1: were bigger that the first stars, the ones made out 551 00:27:12,640 --> 00:27:15,280 Speaker 1: of just hydrogen that came out of the Big Bang 552 00:27:15,440 --> 00:27:17,680 Speaker 1: that had no metals in them, were able to form 553 00:27:17,720 --> 00:27:20,240 Speaker 1: to be like really big three D four hundred even 554 00:27:20,240 --> 00:27:24,119 Speaker 1: five hundred times the mass of the Sun. Interesting because 555 00:27:24,240 --> 00:27:27,080 Speaker 1: just from the from having like the purity of hydrogen, 556 00:27:27,720 --> 00:27:30,760 Speaker 1: or is it that the conditions of space themselves were different. 557 00:27:30,920 --> 00:27:33,119 Speaker 1: It's from having the purity of hydrogen. Like if you 558 00:27:33,160 --> 00:27:36,960 Speaker 1: have heavier stuff around, if you have carbon and nickel 559 00:27:37,080 --> 00:27:40,480 Speaker 1: and heavier elements around from previous stars, that changes the 560 00:27:40,520 --> 00:27:43,119 Speaker 1: way the gas is condensed. It makes it easier for 561 00:27:43,160 --> 00:27:46,000 Speaker 1: gas to cool because you have these heavier elements. That's 562 00:27:46,040 --> 00:27:48,160 Speaker 1: what's needed for a big blob of gas to turn 563 00:27:48,200 --> 00:27:50,840 Speaker 1: into the stars that has sort of cool together. If 564 00:27:50,840 --> 00:27:54,199 Speaker 1: it's hot enough, gravity will never attract it down into clumps, right, 565 00:27:54,200 --> 00:27:57,280 Speaker 1: It needs to cool enough to form a star. And 566 00:27:57,359 --> 00:28:01,040 Speaker 1: so if you have all hydrogen, it's harder to cool 567 00:28:01,200 --> 00:28:03,680 Speaker 1: small clumps, and so they tend to cool in these 568 00:28:03,720 --> 00:28:07,679 Speaker 1: big blobs, and so you get these really massive early stars. 569 00:28:07,680 --> 00:28:11,040 Speaker 1: Now nobody's ever seen these. They're called population three stars 570 00:28:11,040 --> 00:28:13,639 Speaker 1: and they're the very first population of stars in the 571 00:28:13,720 --> 00:28:17,119 Speaker 1: universe really big, would have burned really fast, wouldn't have 572 00:28:17,160 --> 00:28:20,639 Speaker 1: lived very long, but they could have then collapsed to 573 00:28:20,720 --> 00:28:24,439 Speaker 1: form pretty massive black holes like two hundred three hundred 574 00:28:24,440 --> 00:28:27,800 Speaker 1: times the mass of the Sun, which could form seeds 575 00:28:27,840 --> 00:28:31,399 Speaker 1: that give us super massive black holes today. WHOA, So 576 00:28:31,440 --> 00:28:34,840 Speaker 1: we have a hypothetical giant star at the beginning of 577 00:28:34,880 --> 00:28:39,160 Speaker 1: the universe that somehow becomes a hypothetical medium sized black hole, 578 00:28:39,920 --> 00:28:42,440 Speaker 1: but then grows to become the super massive black holes 579 00:28:42,520 --> 00:28:45,200 Speaker 1: we see today. That's right, that's the idea, and it's 580 00:28:45,200 --> 00:28:47,280 Speaker 1: pretty cool and it makes some sense and you don't 581 00:28:47,280 --> 00:28:50,160 Speaker 1: have to like invoke any new magic physics or anything. 582 00:28:50,400 --> 00:28:54,160 Speaker 1: But it's also doesn't quite work. One reason is, like, 583 00:28:54,520 --> 00:28:56,480 Speaker 1: how many of these could there have been? Like, the 584 00:28:56,480 --> 00:28:59,120 Speaker 1: theory suggests that we don't expect enough of these to 585 00:28:59,280 --> 00:29:02,320 Speaker 1: explain all the supermassive black holes that we see. What 586 00:29:02,320 --> 00:29:04,400 Speaker 1: do you mean you don't see enough? Well, we see 587 00:29:04,400 --> 00:29:07,240 Speaker 1: a supermassive black hole in the center of every single galaxy, 588 00:29:07,680 --> 00:29:11,320 Speaker 1: and we don't expect every single proto galaxy to form 589 00:29:11,400 --> 00:29:15,440 Speaker 1: these supermassive stars like it happens sometimes, but not enough 590 00:29:15,640 --> 00:29:17,720 Speaker 1: to give us all the supermassive black holes that we 591 00:29:17,720 --> 00:29:21,240 Speaker 1: see today, So it might explain some fraction of them, 592 00:29:21,320 --> 00:29:24,200 Speaker 1: but not all of them. And the other problem is 593 00:29:24,240 --> 00:29:27,200 Speaker 1: that they're not quite big enough. Like three d four 594 00:29:27,240 --> 00:29:29,360 Speaker 1: hundred times the mass of the sun. That's pretty good. 595 00:29:29,400 --> 00:29:31,640 Speaker 1: It's better than starting from you know, five times the 596 00:29:31,640 --> 00:29:33,960 Speaker 1: mass of the sun. But if you start from there, 597 00:29:34,000 --> 00:29:36,520 Speaker 1: you've got to grow with the maximum rate the entire 598 00:29:36,640 --> 00:29:39,720 Speaker 1: time to get close to the supermassive black holes. And 599 00:29:39,760 --> 00:29:42,840 Speaker 1: it's really on the edge. And nobody thinks the black 600 00:29:42,840 --> 00:29:46,320 Speaker 1: holes can grow at the Eddington limit at the maximum 601 00:29:46,400 --> 00:29:50,560 Speaker 1: rate their entire lifetime. It requires like exact, delicate balance 602 00:29:50,640 --> 00:29:53,600 Speaker 1: of gases being fed in just the right way to 603 00:29:53,720 --> 00:29:57,880 Speaker 1: hit that maximum. So it's kind of precarious. And can 604 00:29:57,920 --> 00:30:00,440 Speaker 1: you have even bigger stars or is or a limit 605 00:30:00,480 --> 00:30:02,160 Speaker 1: to how big a star can be? Yeah, we don't 606 00:30:02,160 --> 00:30:05,000 Speaker 1: think that these population three stars can get much bigger 607 00:30:05,040 --> 00:30:07,480 Speaker 1: than that, and so that sort of limits the size 608 00:30:07,520 --> 00:30:10,720 Speaker 1: of those seeds. Right, So then what's the third way 609 00:30:10,800 --> 00:30:13,520 Speaker 1: in which supermassive black holes can form. Well, the third 610 00:30:13,520 --> 00:30:16,520 Speaker 1: way is to skip the star formation and say let's 611 00:30:16,560 --> 00:30:18,800 Speaker 1: have a big blob of gas in the early universe. 612 00:30:19,240 --> 00:30:21,840 Speaker 1: And let's assume that there's a really like dense blob 613 00:30:21,880 --> 00:30:24,520 Speaker 1: of dark matter in the center of it. Dark matter. 614 00:30:24,560 --> 00:30:27,240 Speaker 1: We know there's more dark matter than any other matter 615 00:30:27,280 --> 00:30:30,600 Speaker 1: in the universe. It's this invisible stuff that's around us, 616 00:30:30,840 --> 00:30:33,320 Speaker 1: but it has gravity, and it's the most of the 617 00:30:33,360 --> 00:30:35,280 Speaker 1: gravity in the universe, and so it plays a big 618 00:30:35,360 --> 00:30:38,000 Speaker 1: role in how stuff clumps together. So if you've got 619 00:30:38,000 --> 00:30:41,680 Speaker 1: a big blob of dark matter around in this early gas, 620 00:30:41,720 --> 00:30:44,360 Speaker 1: it could have collapsed a huge blob of stuff down 621 00:30:44,720 --> 00:30:47,000 Speaker 1: straight to a black hole like skip the whole star 622 00:30:47,080 --> 00:30:50,200 Speaker 1: step just from the dark matter. Just from the dark matter. 623 00:30:50,240 --> 00:30:53,360 Speaker 1: I mean, dark matter creates a gravitational well, right, so 624 00:30:53,480 --> 00:30:56,040 Speaker 1: all this stuff falls into it and it doesn't have 625 00:30:56,120 --> 00:31:00,080 Speaker 1: the outward pressure of of gas pushing out, and so 626 00:31:00,160 --> 00:31:02,600 Speaker 1: stuff can just fall in. And if that happens, people 627 00:31:02,600 --> 00:31:04,720 Speaker 1: have these models where you can form black holes in 628 00:31:04,720 --> 00:31:08,000 Speaker 1: the very early universe that are already like thousands or 629 00:31:08,080 --> 00:31:10,840 Speaker 1: tens of thousands of masses of the sun. Oh. I see, 630 00:31:10,840 --> 00:31:13,239 Speaker 1: like the dark matter gives you that extra boost, like 631 00:31:13,280 --> 00:31:16,880 Speaker 1: the secret steroid or something. Yeah, you're like no, no, no, 632 00:31:17,360 --> 00:31:21,680 Speaker 1: dark matter, like the super different high protein diet kind 633 00:31:21,680 --> 00:31:25,160 Speaker 1: of that's right exactly. I don't recommend the dark matter diet, 634 00:31:25,280 --> 00:31:27,720 Speaker 1: but you will lose weight. So this gives you higher 635 00:31:27,760 --> 00:31:30,080 Speaker 1: mass black holes, which is cool. It gets you like 636 00:31:30,160 --> 00:31:32,760 Speaker 1: further up the ladder, gets you closer. You don't have 637 00:31:32,840 --> 00:31:35,640 Speaker 1: to grow as much and as aggressively to get to 638 00:31:35,680 --> 00:31:38,920 Speaker 1: the black holes we see today. But it's also less 639 00:31:38,960 --> 00:31:42,400 Speaker 1: likely and so these things might happen, but there would 640 00:31:42,440 --> 00:31:45,040 Speaker 1: be more rare. So they also can't explain all the 641 00:31:45,080 --> 00:31:47,520 Speaker 1: supermassive black holes that we see out. Why do we 642 00:31:47,560 --> 00:31:50,160 Speaker 1: think that they're rare? Is in dark matter everywhere? And 643 00:31:50,200 --> 00:31:53,920 Speaker 1: couldn't these concentrations of dark matter happen all the time? Yes, 644 00:31:54,000 --> 00:31:56,120 Speaker 1: dark matter is everywhere and there's a lot of it. 645 00:31:56,440 --> 00:31:59,120 Speaker 1: But to make a big black hole out of a 646 00:31:59,120 --> 00:32:01,560 Speaker 1: blob of stuff, you need a big fluctuation in the 647 00:32:01,560 --> 00:32:04,280 Speaker 1: amount of dark matter, and so that's just less likely happened, 648 00:32:04,400 --> 00:32:06,280 Speaker 1: like in the density of it. Yeah, exactly, it's like 649 00:32:06,280 --> 00:32:09,479 Speaker 1: a statistical argument. You know, you distribute dark matter randomly 650 00:32:09,480 --> 00:32:12,000 Speaker 1: through the universe, you're gonna get clumps. How big are 651 00:32:12,000 --> 00:32:14,640 Speaker 1: those clumps? Well, to get really big clumps, it's going 652 00:32:14,680 --> 00:32:17,640 Speaker 1: to be less likely. I guess a question I have 653 00:32:17,760 --> 00:32:20,520 Speaker 1: is if you have a black hole with dark matter 654 00:32:20,640 --> 00:32:23,680 Speaker 1: in it, the dark matter can leave either. That's right, 655 00:32:23,760 --> 00:32:29,280 Speaker 1: dark matters also gravitationally bound. Everything is gravitationally bound, neutrinos, photons, 656 00:32:29,400 --> 00:32:33,160 Speaker 1: dark matter. Because remember, it's not just like a powerful 657 00:32:33,200 --> 00:32:36,080 Speaker 1: force holding onto you that you could maybe ignore if 658 00:32:36,080 --> 00:32:38,440 Speaker 1: you're a particle that doesn't have the right charges. It's 659 00:32:38,440 --> 00:32:41,400 Speaker 1: a shape of space, like inside the black hole. Space 660 00:32:41,600 --> 00:32:44,400 Speaker 1: is one directional, So if you're inside the black hole, 661 00:32:44,760 --> 00:32:47,680 Speaker 1: any direction you go brings you closer to the center 662 00:32:47,760 --> 00:32:49,880 Speaker 1: of the black hole. So it doesn't really matter how 663 00:32:49,960 --> 00:32:52,160 Speaker 1: fast or strong or weak you are. All right, Now, 664 00:32:52,240 --> 00:32:56,160 Speaker 1: let's get into how they could possibly grow as much 665 00:32:56,200 --> 00:32:59,240 Speaker 1: as they are now and if we could ever escape 666 00:32:59,280 --> 00:33:01,720 Speaker 1: these super mess black holes. But first let's take another 667 00:33:01,800 --> 00:33:17,760 Speaker 1: quick break. Alright, we're talking about super massive black holes 668 00:33:17,800 --> 00:33:20,640 Speaker 1: and how they form, which is a big mystery. So 669 00:33:20,760 --> 00:33:22,520 Speaker 1: the main idea that I guess you're telling me is 670 00:33:22,560 --> 00:33:25,880 Speaker 1: that maybe super massive black holes started out big. That's right. 671 00:33:26,040 --> 00:33:29,560 Speaker 1: They were always big. They were always be that's what 672 00:33:29,600 --> 00:33:32,440 Speaker 1: you're telling me. It's like the baby came out huge, 673 00:33:32,520 --> 00:33:36,320 Speaker 1: you know, that's why he's so tall. He came out tall. Oh, 674 00:33:36,400 --> 00:33:40,320 Speaker 1: that's terrifying from the parenting point of view. So there 675 00:33:40,320 --> 00:33:43,880 Speaker 1: are three possibilities. Maybe they formed huge in the primordial 676 00:33:43,920 --> 00:33:46,920 Speaker 1: soup of the universe, or maybe they came from really 677 00:33:47,000 --> 00:33:50,600 Speaker 1: big stars, or maybe dark matter was involved. And so 678 00:33:50,760 --> 00:33:54,240 Speaker 1: does that mean that they came into being as big 679 00:33:54,280 --> 00:33:56,240 Speaker 1: as they are now or would they still need to 680 00:33:56,320 --> 00:33:58,840 Speaker 1: grow some to see what we see now? Well, the 681 00:33:58,840 --> 00:34:01,480 Speaker 1: black holes that we see now are much bigger than 682 00:34:01,520 --> 00:34:03,640 Speaker 1: those seeds we just talked about. Those seeds get up 683 00:34:03,680 --> 00:34:06,320 Speaker 1: to like maybe tens of thousands of times the mass 684 00:34:06,320 --> 00:34:08,680 Speaker 1: of the sun. The black holes we see out there, 685 00:34:08,920 --> 00:34:11,760 Speaker 1: they get up to, you know, like five ten billion 686 00:34:11,960 --> 00:34:14,560 Speaker 1: times the mass of the sun. And so you definitely 687 00:34:14,600 --> 00:34:16,760 Speaker 1: got to grow it. It's like that's a good seedling. 688 00:34:17,000 --> 00:34:18,520 Speaker 1: You know, if you're a gardener, you know, it's much 689 00:34:18,520 --> 00:34:21,160 Speaker 1: harder to get something growing from a little seed up 690 00:34:21,200 --> 00:34:23,520 Speaker 1: to a big, robust plant. Somebody gives you a seedling 691 00:34:23,760 --> 00:34:25,440 Speaker 1: than boom, you can just water it and sun it. 692 00:34:25,760 --> 00:34:29,000 Speaker 1: You have something giving you tomatoes, it's already going. Yeah, 693 00:34:29,040 --> 00:34:32,040 Speaker 1: it's already going. And so these are basically like black 694 00:34:32,040 --> 00:34:34,319 Speaker 1: hole seedlings, but you still got to grow them to 695 00:34:34,360 --> 00:34:36,480 Speaker 1: get them as big as the stuff that we see 696 00:34:36,520 --> 00:34:39,400 Speaker 1: and is there a mystery there or you know, if 697 00:34:39,440 --> 00:34:42,840 Speaker 1: you if you start with like a ten thousand solar 698 00:34:42,920 --> 00:34:45,240 Speaker 1: mass black hole, can you get up to those billions 699 00:34:45,360 --> 00:34:48,400 Speaker 1: of super massive black holes? You can? But it's hard, 700 00:34:48,480 --> 00:34:51,640 Speaker 1: like you gotta really ride the edge. You know. These 701 00:34:51,640 --> 00:34:53,799 Speaker 1: are questions that are not like physical limits. It's not 702 00:34:53,880 --> 00:34:56,640 Speaker 1: like there's some reason why a black hole can't get 703 00:34:56,640 --> 00:34:59,560 Speaker 1: any bigger. In fact, there's no theoretical limit on the 704 00:34:59,640 --> 00:35:01,799 Speaker 1: size of a black hole, but there are sort of 705 00:35:01,920 --> 00:35:05,040 Speaker 1: environmental limits, Like you need to create the situation where 706 00:35:05,040 --> 00:35:07,520 Speaker 1: a black hole has the stuff it needs to eat, 707 00:35:07,520 --> 00:35:09,560 Speaker 1: because tends to just like gobble of stuff around it 708 00:35:09,800 --> 00:35:12,720 Speaker 1: and then push the stuff away. So that's this balance 709 00:35:12,719 --> 00:35:15,320 Speaker 1: we were talking about earlier, right, because black holes emit 710 00:35:15,400 --> 00:35:18,320 Speaker 1: a lot of radiation and sort of in all directions, 711 00:35:18,360 --> 00:35:20,680 Speaker 1: pushing away from themselves the stuff that they would need 712 00:35:20,719 --> 00:35:23,440 Speaker 1: to eat to get bigger. Right, And also like you know, 713 00:35:23,480 --> 00:35:25,640 Speaker 1: if it has to eat that much, where does it 714 00:35:25,680 --> 00:35:28,160 Speaker 1: get all that food? Like if a black hole is 715 00:35:28,640 --> 00:35:30,719 Speaker 1: ten million times the size of the Sun, it has 716 00:35:30,719 --> 00:35:33,920 Speaker 1: to eat ten million sons. Yeah, precisely, And for example, 717 00:35:33,920 --> 00:35:36,600 Speaker 1: the black hole the center of our galaxy, how much 718 00:35:36,640 --> 00:35:38,840 Speaker 1: bigger could it get. It could only get about a 719 00:35:38,880 --> 00:35:42,000 Speaker 1: thousand times bigger, because that's all the mass that's in 720 00:35:42,040 --> 00:35:45,560 Speaker 1: our galaxy. If it ate every single star and blob 721 00:35:45,600 --> 00:35:47,640 Speaker 1: of stuff in the galaxy, that would only give it 722 00:35:47,680 --> 00:35:50,680 Speaker 1: a factor of a thousand. So if you see a 723 00:35:50,840 --> 00:35:53,360 Speaker 1: black hole out there that's a million or a billion 724 00:35:53,400 --> 00:35:56,200 Speaker 1: times the size of the Sun, that means it it 725 00:35:56,520 --> 00:35:59,560 Speaker 1: ate that much. And so you know, I like, how 726 00:35:59,640 --> 00:36:02,160 Speaker 1: much big or what's the galaxy? He sounds so judgmental, 727 00:36:02,200 --> 00:36:04,120 Speaker 1: like somebody who you know, had to pop their bells 728 00:36:04,120 --> 00:36:06,040 Speaker 1: after dinner, like, hey man, you shouldn't have had that 729 00:36:06,120 --> 00:36:15,800 Speaker 1: sixth plate. I think if you eat a few billion sons, Yeah, yeah, exactly. 730 00:36:15,840 --> 00:36:18,320 Speaker 1: And it's just sort of hard to arrange the stuff 731 00:36:18,320 --> 00:36:20,360 Speaker 1: and the right conveyor belt to get it there. And 732 00:36:20,400 --> 00:36:23,719 Speaker 1: so they've calculated what is the maximum effective rate that 733 00:36:23,800 --> 00:36:26,200 Speaker 1: a black hole can grow. It's called this Eddington limit, 734 00:36:26,719 --> 00:36:30,200 Speaker 1: and it's possible to sometimes have what they call super 735 00:36:30,400 --> 00:36:33,960 Speaker 1: Eddington growth, but only very very briefly. And it's because 736 00:36:34,000 --> 00:36:36,839 Speaker 1: the radiation that increases a lot and blows out the gas. 737 00:36:36,880 --> 00:36:40,160 Speaker 1: The highest stable rate requires a special configuration. You've got 738 00:36:40,160 --> 00:36:42,360 Speaker 1: to have just the right amount of cold gas falling 739 00:36:42,400 --> 00:36:44,680 Speaker 1: into the black hole and just the right way. It's 740 00:36:44,680 --> 00:36:48,160 Speaker 1: a bit tricky to arrange. Instead of get these seedlings 741 00:36:48,480 --> 00:36:51,200 Speaker 1: up to the massive black holes that we see today, 742 00:36:51,560 --> 00:36:55,319 Speaker 1: requires a sort of unusual, unlikely arrangement of stuff to 743 00:36:55,400 --> 00:36:57,879 Speaker 1: fall into the black hole at just the right rate, 744 00:36:58,239 --> 00:37:01,839 Speaker 1: like perfectly funnel into it with causing a big message. Yeah. 745 00:37:02,120 --> 00:37:04,160 Speaker 1: And you know another way these things can get bigger 746 00:37:04,239 --> 00:37:07,000 Speaker 1: is by merging, Like you can merge two galaxies. Two 747 00:37:07,000 --> 00:37:09,440 Speaker 1: galaxies collides because you know, on the scale of like 748 00:37:09,560 --> 00:37:12,200 Speaker 1: the universe, each galaxy is like a dot, and you 749 00:37:12,239 --> 00:37:14,040 Speaker 1: can think of it like a particle and a gas 750 00:37:14,040 --> 00:37:16,560 Speaker 1: flying around, and occasionally they get close to each other 751 00:37:16,600 --> 00:37:19,759 Speaker 1: and they emerge, like our galaxy the Milky Way is 752 00:37:19,800 --> 00:37:22,640 Speaker 1: going to merge with Andromeda in a few billion years. 753 00:37:22,719 --> 00:37:25,719 Speaker 1: And Andromeda's black holes even bigger than hours. It's like 754 00:37:25,920 --> 00:37:29,200 Speaker 1: dwarfs our black hole. And and so these two things 755 00:37:29,239 --> 00:37:31,479 Speaker 1: are going to collide, and eventually those two black holes 756 00:37:31,480 --> 00:37:34,640 Speaker 1: in the center will spiral around each other and via 757 00:37:34,680 --> 00:37:37,799 Speaker 1: the emission of gravitational waves, become one and so will 758 00:37:37,840 --> 00:37:41,120 Speaker 1: become an even bigger black hole. Wow. I guess one 759 00:37:41,280 --> 00:37:43,839 Speaker 1: curious question I have is um, you know, why do 760 00:37:43,880 --> 00:37:46,520 Speaker 1: we see them at the center of galaxies? Like, you 761 00:37:46,560 --> 00:37:50,040 Speaker 1: never see a supermassive black hole not inside of a galaxy, 762 00:37:50,120 --> 00:37:52,719 Speaker 1: do you know? You don't. And the reason is that 763 00:37:52,760 --> 00:37:55,680 Speaker 1: they need stuff to grow. Like if you had the 764 00:37:55,760 --> 00:37:57,960 Speaker 1: seed of a supermassive black hole just out there in 765 00:37:57,960 --> 00:37:59,920 Speaker 1: the middle of the universe, it couldn't grow. It's got 766 00:38:00,000 --> 00:38:02,600 Speaker 1: to be surrounded by stuff. That's why there's like a 767 00:38:02,600 --> 00:38:05,840 Speaker 1: correlation between the size of the supermassive black hole and 768 00:38:05,880 --> 00:38:09,240 Speaker 1: the size of the galaxy. Bigger galaxies have bigger black 769 00:38:09,239 --> 00:38:12,239 Speaker 1: holes at their centers just because there's more fuel for 770 00:38:12,280 --> 00:38:15,600 Speaker 1: them to eat, and smaller galaxies have smaller black holes 771 00:38:15,640 --> 00:38:18,320 Speaker 1: because there's less fuel for them to eat. And so 772 00:38:18,680 --> 00:38:21,680 Speaker 1: it makes sense, But it sounds sort of like a coincidence. 773 00:38:21,719 --> 00:38:25,120 Speaker 1: Almost did these supermassive black holes? Are they one of 774 00:38:25,120 --> 00:38:28,160 Speaker 1: the reasons the galaxy form? Or is it sort of 775 00:38:28,160 --> 00:38:32,400 Speaker 1: a coincidence that you've got of galaxy forming and you 776 00:38:32,480 --> 00:38:34,719 Speaker 1: also had a seedling for a massive black hole in 777 00:38:34,760 --> 00:38:36,640 Speaker 1: the middle, and so that's why you have them in 778 00:38:36,680 --> 00:38:38,400 Speaker 1: the middle of galaxies. I think it's the opposite. I 779 00:38:38,400 --> 00:38:42,000 Speaker 1: think that larger galaxies are going to form supermassive black 780 00:38:42,000 --> 00:38:44,839 Speaker 1: holes just because they have the fuel around. And so 781 00:38:44,880 --> 00:38:47,120 Speaker 1: I think if you take a big distribution of galaxies 782 00:38:47,120 --> 00:38:49,360 Speaker 1: of different sizes and you put a seedling at the 783 00:38:49,360 --> 00:38:52,000 Speaker 1: center of each one of them, the larger galaxies will 784 00:38:52,040 --> 00:38:55,480 Speaker 1: grow their black holes faster, and we'll get to bigger sizes. Oh, 785 00:38:55,520 --> 00:38:58,880 Speaker 1: I see, So galaxies form for other reasons. But they 786 00:38:58,920 --> 00:39:01,840 Speaker 1: all sort had a sprinkle of super massive black holes, 787 00:39:02,320 --> 00:39:05,040 Speaker 1: the seeds of super massive black holes, And so the 788 00:39:05,040 --> 00:39:08,120 Speaker 1: seeds that fell and the larger galaxies got bigger. Yeah, 789 00:39:08,200 --> 00:39:11,480 Speaker 1: and the galaxies formed because actually of dark matter, right, 790 00:39:11,560 --> 00:39:15,480 Speaker 1: dark matter forms these gravitational wells somewhere out there. Dark 791 00:39:15,520 --> 00:39:18,080 Speaker 1: matter is not just smoothly distributed through the universe like 792 00:39:18,160 --> 00:39:21,160 Speaker 1: some soup. It's got blobs and and chunks to it, 793 00:39:21,440 --> 00:39:24,120 Speaker 1: and galaxies form in those blobs and chunks. It's the 794 00:39:24,200 --> 00:39:27,319 Speaker 1: reason we have galaxies. If you delete dark matter from 795 00:39:27,320 --> 00:39:30,640 Speaker 1: the universe, you don't even get galaxies by ten billion years. 796 00:39:30,800 --> 00:39:32,879 Speaker 1: You've gotta wait a lot longer for gravity to pull 797 00:39:33,120 --> 00:39:35,560 Speaker 1: just the normal matter together. So the reason you have 798 00:39:35,640 --> 00:39:38,440 Speaker 1: these galaxies and those seed things together is because the 799 00:39:38,520 --> 00:39:40,839 Speaker 1: dark matter sort of like forming the pot in which 800 00:39:40,880 --> 00:39:43,120 Speaker 1: all this stuff is growing, all right, and all that 801 00:39:43,160 --> 00:39:45,600 Speaker 1: points are kind of a maximum size of black holes. 802 00:39:45,800 --> 00:39:49,120 Speaker 1: You're saying that the maximum size that a black hole 803 00:39:49,280 --> 00:39:52,799 Speaker 1: can be is about ten billion sons. Yeah, so why 804 00:39:52,840 --> 00:39:55,520 Speaker 1: is it? Is it just because we don't see galaxies 805 00:39:55,520 --> 00:39:57,480 Speaker 1: that are bigger than ten billion times the mass of 806 00:39:57,480 --> 00:40:00,200 Speaker 1: our sun? Yeah, it's not a theoretical limit, right, could 807 00:40:00,239 --> 00:40:02,719 Speaker 1: in principle form a black hole that's larger. But if 808 00:40:02,719 --> 00:40:05,640 Speaker 1: you ask, like, what's the largest size black hole we 809 00:40:05,680 --> 00:40:08,759 Speaker 1: expect to exist in the universe right now, given the 810 00:40:08,800 --> 00:40:11,040 Speaker 1: time they've had to form in the size of galaxies, 811 00:40:11,160 --> 00:40:13,920 Speaker 1: then we think that's about ten billion times the mass 812 00:40:13,920 --> 00:40:16,840 Speaker 1: of the Sun. So it's an environmental limit, not a 813 00:40:16,880 --> 00:40:20,279 Speaker 1: fundamental limit. And these biggest black holes, the ones that 814 00:40:20,320 --> 00:40:22,439 Speaker 1: are like billions of times of the mass of the Sun, 815 00:40:23,160 --> 00:40:25,960 Speaker 1: we see them in galaxies that have very little gas 816 00:40:26,680 --> 00:40:29,560 Speaker 1: means they've already sucked up most of the fuel. Okay, 817 00:40:29,640 --> 00:40:32,279 Speaker 1: so the ones that are smaller have more fuel around them, 818 00:40:32,480 --> 00:40:35,200 Speaker 1: they still have a place to grow, and so there's 819 00:40:35,200 --> 00:40:37,240 Speaker 1: not really much more room for them to grow unless 820 00:40:37,239 --> 00:40:39,960 Speaker 1: they merge with another supermassive black hole. Could you have 821 00:40:40,000 --> 00:40:43,200 Speaker 1: had like a really big galaxy you know, could you 822 00:40:43,400 --> 00:40:47,279 Speaker 1: have formed a really much bigger galaxy or is that rare? Yeah, 823 00:40:47,280 --> 00:40:48,919 Speaker 1: that's a really fun idea. You know. It's a question 824 00:40:48,960 --> 00:40:51,960 Speaker 1: of like how big could a galaxy get? And remember 825 00:40:52,000 --> 00:40:54,640 Speaker 1: we talked about this in our episode last week about 826 00:40:54,640 --> 00:40:56,920 Speaker 1: the sort of structure formation of the universe. Things sort 827 00:40:56,920 --> 00:40:59,880 Speaker 1: of form bottom up and clump together, and there's a 828 00:41:00,000 --> 00:41:02,880 Speaker 1: balanced there between like the initial velocity of this stuff 829 00:41:03,200 --> 00:41:06,160 Speaker 1: and the gravity to pull it together. And so space 830 00:41:06,280 --> 00:41:09,839 Speaker 1: is expanding and pulling stuff apart, and things have velocities 831 00:41:10,120 --> 00:41:13,480 Speaker 1: which prevent them from clumping together and this gravity pulling 832 00:41:13,480 --> 00:41:16,040 Speaker 1: stuff together. So what limits sort of the size of 833 00:41:16,040 --> 00:41:18,480 Speaker 1: the galaxy is just like how much stuff you can 834 00:41:18,520 --> 00:41:22,520 Speaker 1: get together in a gravitational well before dark energy takes 835 00:41:22,560 --> 00:41:24,799 Speaker 1: over and starts pulling things apart. And so we think 836 00:41:24,840 --> 00:41:27,319 Speaker 1: that there is a limit to how big galaxies could 837 00:41:27,320 --> 00:41:29,560 Speaker 1: have gotten in the early universe. I see, which then 838 00:41:29,640 --> 00:41:32,920 Speaker 1: limits the black hole. It does unfortunately, I know, thankfully, 839 00:41:33,080 --> 00:41:36,799 Speaker 1: I guess maybe. I mean, if you were that black hole, 840 00:41:36,840 --> 00:41:39,080 Speaker 1: you probably want to get bigger, or maybe you'd be like, 841 00:41:39,280 --> 00:41:41,280 Speaker 1: thank you for putting that stuff away in the fridge 842 00:41:41,320 --> 00:41:43,719 Speaker 1: so I don't eat too much. Yeah, you know, like, 843 00:41:44,080 --> 00:41:47,359 Speaker 1: we'll slow down there, you know, I think you've had enough. 844 00:41:48,160 --> 00:41:51,080 Speaker 1: You know, limits are good? All right? Well, um, so 845 00:41:51,160 --> 00:41:53,440 Speaker 1: that's a big mystery, I guess. And and do we 846 00:41:53,560 --> 00:41:55,800 Speaker 1: do we have to worry about these super massive black holes, 847 00:41:55,880 --> 00:41:59,360 Speaker 1: like are they dangerous or maybe they help galaxies actually 848 00:41:59,400 --> 00:42:02,279 Speaker 1: stay together? They do help galaxy stay together. And there 849 00:42:02,360 --> 00:42:05,280 Speaker 1: is one really big one at the center of our galaxy. 850 00:42:05,320 --> 00:42:07,960 Speaker 1: You know, it's like four million times the mass of 851 00:42:07,960 --> 00:42:10,880 Speaker 1: the Sun, which is big and incredible, but on the 852 00:42:10,920 --> 00:42:14,359 Speaker 1: scale of supermassive black holes, not that big. And it's 853 00:42:14,400 --> 00:42:19,280 Speaker 1: like sixty million kilometers in diameter, which again seems massive, 854 00:42:19,600 --> 00:42:22,920 Speaker 1: but compared to other black holes, is really not that large. 855 00:42:22,920 --> 00:42:25,640 Speaker 1: For a black hole, the size of it, the distance 856 00:42:25,680 --> 00:42:29,440 Speaker 1: from the center to the event horizon, grows linearly with mass, 857 00:42:29,480 --> 00:42:31,239 Speaker 1: so you're like, you double the amount of stuff in it, 858 00:42:31,360 --> 00:42:34,799 Speaker 1: the radius gets twice as big, which weirdly means they're 859 00:42:34,800 --> 00:42:38,839 Speaker 1: not actually that dense. Like a supermassive black hole has 860 00:42:38,880 --> 00:42:42,200 Speaker 1: about the density of water. What you mean where the 861 00:42:42,200 --> 00:42:45,920 Speaker 1: event horizon starts, Yeah, exactly, Like all the stuff contained 862 00:42:46,040 --> 00:42:48,719 Speaker 1: in the black hole, divided by the volume of the 863 00:42:48,719 --> 00:42:51,520 Speaker 1: black hole has about the density of water and it's 864 00:42:51,600 --> 00:42:54,880 Speaker 1: incredible amount of gravity because it's just so much stuff. 865 00:42:55,360 --> 00:42:58,239 Speaker 1: But when you double the amount of stuff inside your 866 00:42:58,239 --> 00:43:01,280 Speaker 1: black hole, you double the radius, which makes the volume 867 00:43:01,320 --> 00:43:03,120 Speaker 1: go up by a factor of eight, and so the 868 00:43:03,160 --> 00:43:06,680 Speaker 1: density actually goes down. So the largerer black hole, the 869 00:43:06,760 --> 00:43:10,120 Speaker 1: less the density. It's like dark waters. I don't recommend 870 00:43:10,160 --> 00:43:12,320 Speaker 1: drinking it. You know, get one of those filters or something. 871 00:43:13,040 --> 00:43:15,000 Speaker 1: But in our galaxy, the black hole doesn't eat a 872 00:43:15,000 --> 00:43:18,080 Speaker 1: star that often. It's like every ten thousand years or 873 00:43:18,080 --> 00:43:20,399 Speaker 1: so a star will get sucked into the black hole. 874 00:43:20,400 --> 00:43:24,120 Speaker 1: It's pretty rare really. Mostly it's just sitting there. But 875 00:43:24,239 --> 00:43:26,680 Speaker 1: is it Is it eating gas? Like, are there funnels 876 00:43:26,680 --> 00:43:28,759 Speaker 1: of gas going in? There are funnels of gas that 877 00:43:28,800 --> 00:43:31,240 Speaker 1: it's still eating. But you know, the stars are mostly 878 00:43:31,280 --> 00:43:33,359 Speaker 1: in stable orbits. The ones that we're going to fall 879 00:43:33,400 --> 00:43:36,319 Speaker 1: in have mostly fallen in, just like our Earth is 880 00:43:36,320 --> 00:43:38,600 Speaker 1: in mostly a stable orbit around the Sun. We don't 881 00:43:38,600 --> 00:43:42,000 Speaker 1: expect to fall into the Sun at any time soon. Now, 882 00:43:42,040 --> 00:43:44,319 Speaker 1: something could come along and disturb our orbit and give 883 00:43:44,360 --> 00:43:45,960 Speaker 1: us a bump, and then we fall into the Sun. 884 00:43:46,320 --> 00:43:48,719 Speaker 1: The same way. If two stars collide, one of them 885 00:43:48,760 --> 00:43:51,160 Speaker 1: could end up getting gobbled up by the black hole. 886 00:43:51,400 --> 00:43:53,440 Speaker 1: But mostly the star is going to escape the black hole. 887 00:43:53,480 --> 00:43:55,440 Speaker 1: They're just gonna be in orbit around it for a 888 00:43:55,480 --> 00:43:57,840 Speaker 1: long long time. And you can think like, well, what 889 00:43:57,880 --> 00:44:01,440 Speaker 1: about in ten trillion years, like do those orbits eventually 890 00:44:01,440 --> 00:44:04,799 Speaker 1: decay because of interactions with interstellar medium? But you know, 891 00:44:05,040 --> 00:44:07,480 Speaker 1: we don't know the future of dark energy or anything 892 00:44:07,719 --> 00:44:09,920 Speaker 1: for ten trillion years, so it's pretty hard to imagine 893 00:44:09,920 --> 00:44:11,759 Speaker 1: what's going to happen that far into the future. Right, 894 00:44:12,520 --> 00:44:14,360 Speaker 1: to think of black holes as pretty scary, But if 895 00:44:14,400 --> 00:44:16,240 Speaker 1: you think about it, our sun is also pretty scary. 896 00:44:16,520 --> 00:44:18,960 Speaker 1: You don't want to fall into the sun either. Our 897 00:44:18,960 --> 00:44:20,879 Speaker 1: sun is pretty scary, and the center of our Earth 898 00:44:20,960 --> 00:44:22,799 Speaker 1: is also scary. You don't want to get down there. 899 00:44:23,200 --> 00:44:26,200 Speaker 1: Anything that's got a lot of gravity is pretty intense 900 00:44:26,320 --> 00:44:29,160 Speaker 1: situation and you know, a good place to avoid. Yeah, 901 00:44:29,200 --> 00:44:31,840 Speaker 1: you don't want to take that situation too lightly. You know, 902 00:44:31,960 --> 00:44:33,840 Speaker 1: it's pretty massive, going to give it the right amount 903 00:44:33,880 --> 00:44:37,240 Speaker 1: of gravity? All right, Well that's the mystery of super 904 00:44:37,280 --> 00:44:40,799 Speaker 1: massive black holes. How do they form so big? How 905 00:44:40,840 --> 00:44:43,480 Speaker 1: big were they when there were babies? Nobody knows? And 906 00:44:43,520 --> 00:44:48,520 Speaker 1: who's been feeding them secretly at the maximum possible woman, No, 907 00:44:48,600 --> 00:44:50,480 Speaker 1: it's like a fun question like how big could a 908 00:44:50,520 --> 00:44:52,600 Speaker 1: tree get if you fit it at just the right rate, 909 00:44:52,680 --> 00:44:55,600 Speaker 1: or with the largest cucumber or pumpkin you could grow 910 00:44:55,640 --> 00:45:00,400 Speaker 1: in your backyard before like implodes into a pumpkin black hole? Right, yeah, 911 00:45:00,480 --> 00:45:02,960 Speaker 1: because it's kind of weird to think that things can 912 00:45:03,040 --> 00:45:05,000 Speaker 1: scale like that, you know, like you could have a 913 00:45:05,160 --> 00:45:07,600 Speaker 1: technically a giant pumpkin, like just like once we had 914 00:45:07,719 --> 00:45:11,160 Speaker 1: giant horses running around, that's right. And if you google 915 00:45:11,200 --> 00:45:14,000 Speaker 1: giant pumpkin, you will be amazed at the size of 916 00:45:14,040 --> 00:45:17,440 Speaker 1: these gourds that people actually can't throw in their backyards 917 00:45:17,520 --> 00:45:19,640 Speaker 1: or in their farms. It's impressive. Could one of these 918 00:45:19,640 --> 00:45:23,480 Speaker 1: collapse into a black hole? Daniel, I think we're pretty safe, 919 00:45:23,640 --> 00:45:25,799 Speaker 1: all right. Well, we hope you enjoyed that. And the 920 00:45:25,840 --> 00:45:28,280 Speaker 1: next time you look out into the universe once again, 921 00:45:28,800 --> 00:45:31,600 Speaker 1: remember the big mysteries that are out there, and even 922 00:45:31,960 --> 00:45:35,239 Speaker 1: the super massive mysteries. That's right, The biggest things out 923 00:45:35,239 --> 00:45:37,920 Speaker 1: there in the universe are things that are not yet understood. 924 00:45:37,960 --> 00:45:40,719 Speaker 1: Scientists are working on this, their eyes puzzled about it 925 00:45:40,960 --> 00:45:44,680 Speaker 1: as we are, which means that their curiosity is your curiosity. 926 00:45:44,840 --> 00:45:47,160 Speaker 1: And it also means that somebody out there, maybe you, 927 00:45:47,360 --> 00:45:50,040 Speaker 1: maybe your kids will be the person to unravel the 928 00:45:50,080 --> 00:45:53,080 Speaker 1: mystery of super massive black holes. That would be super 929 00:45:53,120 --> 00:46:00,239 Speaker 1: massively cool. So thanks for joining us, See you next time. Yea, 930 00:46:04,640 --> 00:46:07,440 Speaker 1: thanks for listening, and remember that Daniel and Jorge Explain 931 00:46:07,520 --> 00:46:10,360 Speaker 1: the Universe is a production of I Heart Radio. For 932 00:46:10,520 --> 00:46:13,439 Speaker 1: more podcast for my heart Radio, visit the I Heart 933 00:46:13,520 --> 00:46:17,120 Speaker 1: Radio Apple Apple Podcasts, or wherever you listen to your 934 00:46:17,200 --> 00:46:17,920 Speaker 1: favorite shows.