1 00:00:08,360 --> 00:00:11,680 Speaker 1: Hey, Daniel, how do you like your coffee in my mouth? 2 00:00:11,760 --> 00:00:15,720 Speaker 1: I guess usually or maybe sometimes in ice cream. I mean, like, 3 00:00:15,760 --> 00:00:18,960 Speaker 1: do you like to drink the tiny, strong Italian coffees 4 00:00:19,160 --> 00:00:23,040 Speaker 1: or the big week American style coffees? Hmmm, I guess 5 00:00:23,040 --> 00:00:25,760 Speaker 1: I like the sort of medium sized coffee, you know, 6 00:00:25,960 --> 00:00:28,360 Speaker 1: strong enough to be for grown ups, but not like 7 00:00:28,400 --> 00:00:31,280 Speaker 1: a punge in the face. I see. And does that 8 00:00:31,360 --> 00:00:34,680 Speaker 1: apply to particles too? Do you prefer tiny particles or 9 00:00:35,159 --> 00:00:37,880 Speaker 1: massive ones? I don't know. I like them heavy enough 10 00:00:37,920 --> 00:00:40,559 Speaker 1: to be rare and worthy of winning a Nobel Prize, 11 00:00:40,920 --> 00:00:43,840 Speaker 1: but light enough that we can discover them at Collider's. 12 00:00:44,080 --> 00:00:47,240 Speaker 1: And you're so middle of the road. Sometimes the middle 13 00:00:47,280 --> 00:01:05,160 Speaker 1: of the road is exactly where the mysteries lie. Hi 14 00:01:05,240 --> 00:01:08,520 Speaker 1: am Jorge, handmade cartoonists and the creator of PhD comics. Hi. 15 00:01:08,640 --> 00:01:12,040 Speaker 1: I'm Daniel. I'm a particle physicist, and I usually eat 16 00:01:12,160 --> 00:01:17,759 Speaker 1: a medium size portion of cookies for breakfast, for lunch, 17 00:01:17,880 --> 00:01:20,720 Speaker 1: or all of the above. Every time you start eating cookies, 18 00:01:20,959 --> 00:01:23,080 Speaker 1: you can't just have one. You try to avoid having 19 00:01:23,120 --> 00:01:25,440 Speaker 1: the whole box, so I end up somewhere in the middle, 20 00:01:25,840 --> 00:01:28,840 Speaker 1: somewhere like half of a box of cookies. Depends are 21 00:01:28,840 --> 00:01:32,160 Speaker 1: you're doing arithmetic half or geometric half, you know, it 22 00:01:32,160 --> 00:01:34,760 Speaker 1: depends on the day. Then you can do zenos paradox 23 00:01:34,800 --> 00:01:36,400 Speaker 1: that can eat half the box, and then you eat 24 00:01:36,440 --> 00:01:38,920 Speaker 1: the other half, and then the half the remaining half, 25 00:01:38,959 --> 00:01:41,959 Speaker 1: and pretty you ate everything but a crumb. Yeah, well, 26 00:01:41,959 --> 00:01:44,200 Speaker 1: that's a great way to avoid eating the whole box, right, 27 00:01:44,400 --> 00:01:47,039 Speaker 1: Wisdom from the ancient Greeks. It's the Greek diet, it's 28 00:01:47,120 --> 00:01:49,960 Speaker 1: the new Mediterranean diet. Only eat half of the remaining 29 00:01:50,000 --> 00:01:52,560 Speaker 1: box of cookies. But welcome to a podcast. Daniel and 30 00:01:52,640 --> 00:01:55,600 Speaker 1: Jorge Explained the Universe, a production of I Heart Radio, 31 00:01:55,760 --> 00:01:58,160 Speaker 1: in which we take a bite of the entire box 32 00:01:58,280 --> 00:02:01,280 Speaker 1: of universe cookies. We chew on the bits to talk 33 00:02:01,320 --> 00:02:03,639 Speaker 1: about black holes, We think about all the little chocolate 34 00:02:03,720 --> 00:02:06,560 Speaker 1: chips that are particles. We dig down into the crumbs 35 00:02:06,560 --> 00:02:09,640 Speaker 1: and try to understand everything that's going out there in space, 36 00:02:10,000 --> 00:02:13,880 Speaker 1: in the universe, in history, and in the future. We 37 00:02:14,120 --> 00:02:17,240 Speaker 1: very humbly try to explain the entire universe to you. 38 00:02:17,440 --> 00:02:20,000 Speaker 1: That's right. There are amazing mysteries all over the universe, 39 00:02:20,040 --> 00:02:25,560 Speaker 1: and those mysteries range from gigantic size galaxy cluster billions 40 00:02:25,600 --> 00:02:29,840 Speaker 1: of light years wide mysteries and really really tiny mysteries 41 00:02:29,919 --> 00:02:33,040 Speaker 1: in the particles and the little quarks and tiny quantum 42 00:02:33,040 --> 00:02:35,480 Speaker 1: fluctuations that make up who we are. Are you saying 43 00:02:35,480 --> 00:02:38,320 Speaker 1: I'm just a quantum fluctuation that I could just disappear tomorrow. 44 00:02:39,919 --> 00:02:42,440 Speaker 1: Well we can all disappear tomorrow, Daniel, depends on what 45 00:02:42,520 --> 00:02:45,440 Speaker 1: you guys are working on at the large handring collider there. Well, 46 00:02:45,440 --> 00:02:47,520 Speaker 1: if we make a black hole, will make a little 47 00:02:47,560 --> 00:02:51,400 Speaker 1: itty bitty when I promise good, I'm glady that's an option. 48 00:02:51,560 --> 00:02:53,480 Speaker 1: I'm so glad you're not tempted at all to just 49 00:02:53,560 --> 00:02:56,360 Speaker 1: dial it up. We'll have a knob here in front 50 00:02:56,400 --> 00:02:58,400 Speaker 1: of me, you know, So tell me what what size 51 00:02:58,400 --> 00:03:00,840 Speaker 1: black hole should we be making here the late see? 52 00:03:00,960 --> 00:03:04,560 Speaker 1: How about a zero sized black hole? That's no fun? 53 00:03:04,600 --> 00:03:06,160 Speaker 1: And how are we going to learn the secrets of 54 00:03:06,200 --> 00:03:09,919 Speaker 1: the universe? Keep you inside the tiny black holes? I'm 55 00:03:09,919 --> 00:03:12,680 Speaker 1: okay where they are right now. But black holes are amazing. 56 00:03:12,720 --> 00:03:16,200 Speaker 1: They are fascinating. They do contain amazing secrets of the 57 00:03:16,240 --> 00:03:20,359 Speaker 1: universe inside them. But there are also really fascinating questions 58 00:03:20,400 --> 00:03:22,920 Speaker 1: about how they get made and why they are the 59 00:03:22,960 --> 00:03:25,960 Speaker 1: size they are or the size they aren't. Yeah, they 60 00:03:25,960 --> 00:03:29,079 Speaker 1: seem to be everyone's favorite space mystery. Do you think 61 00:03:29,080 --> 00:03:30,639 Speaker 1: maybe it was all in the name, Like if you 62 00:03:30,720 --> 00:03:35,120 Speaker 1: had called them, I don't know, vacuum holes or gravity pits, 63 00:03:35,200 --> 00:03:37,160 Speaker 1: do you think people would still be as interested in 64 00:03:37,200 --> 00:03:40,200 Speaker 1: the I think they would. I think it's their fundamentally 65 00:03:40,240 --> 00:03:43,600 Speaker 1: alien nature that makes themselves fascinating. We know they are 66 00:03:43,720 --> 00:03:47,760 Speaker 1: really deeply, weirdly different from anything we have seen before, 67 00:03:48,000 --> 00:03:50,680 Speaker 1: and I think that's what sparks our curiosity. You know, 68 00:03:50,720 --> 00:03:52,560 Speaker 1: we want to go there and see it and explore 69 00:03:52,600 --> 00:03:55,200 Speaker 1: it because we want to understand what's possible in the universe. 70 00:03:55,240 --> 00:03:57,760 Speaker 1: As we say often on the podcast, it's the extreme 71 00:03:57,880 --> 00:04:00,480 Speaker 1: situations that teach us what the rules really are because 72 00:04:00,480 --> 00:04:03,120 Speaker 1: they show us the limits. Yeah, and as you say that, 73 00:04:03,200 --> 00:04:05,000 Speaker 1: you can find them in all kinds of sizes out 74 00:04:05,000 --> 00:04:08,440 Speaker 1: there in space. There are black holes that are humongous 75 00:04:08,480 --> 00:04:11,280 Speaker 1: and warm the center of galaxies and help keep galaxies 76 00:04:11,320 --> 00:04:13,640 Speaker 1: kind of together, and you can make them tiny little 77 00:04:13,640 --> 00:04:15,960 Speaker 1: ones that evaporate right away. Yeah, that's right. There are 78 00:04:16,000 --> 00:04:19,080 Speaker 1: these funny, two different populations of black holes, the ones 79 00:04:19,120 --> 00:04:21,680 Speaker 1: that seem to come from the collapse of stars and 80 00:04:21,760 --> 00:04:24,880 Speaker 1: the huge galaxy gobblers at the center of many galaxies, 81 00:04:25,160 --> 00:04:27,360 Speaker 1: and the weak thing is that there don't seem to 82 00:04:27,400 --> 00:04:31,440 Speaker 1: be any in between. Really, there's no like Goldilocks black holes. 83 00:04:31,839 --> 00:04:35,599 Speaker 1: There's only two options, like VENTI and X are large. 84 00:04:35,680 --> 00:04:37,960 Speaker 1: That's right. You either don't open the box of cookies 85 00:04:38,080 --> 00:04:40,640 Speaker 1: or you eat the whole thing. The universe never goes 86 00:04:40,680 --> 00:04:43,440 Speaker 1: for half a box. Yeah, so there are mostly two 87 00:04:43,480 --> 00:04:46,080 Speaker 1: sizes of black holes in the universe. One you're saying 88 00:04:46,120 --> 00:04:48,359 Speaker 1: it are the ones that come from the collapse of stars. 89 00:04:48,440 --> 00:04:50,359 Speaker 1: Those are I mean, they're pretty big. There's still like 90 00:04:50,400 --> 00:04:53,960 Speaker 1: the size of you know, many suns. Yes, these are small, 91 00:04:54,040 --> 00:04:57,040 Speaker 1: only on the sort of like cosmic galactic scale, right, 92 00:04:57,120 --> 00:05:00,560 Speaker 1: smaller than a whole galaxy. Still a normal is still 93 00:05:00,600 --> 00:05:04,640 Speaker 1: more massive than our entire solar system. But yeah, tiny 94 00:05:04,760 --> 00:05:07,880 Speaker 1: compared to other things. And then you have the huge ones, 95 00:05:08,000 --> 00:05:10,360 Speaker 1: the ones that are how many, like millions of times 96 00:05:10,360 --> 00:05:12,359 Speaker 1: the mass of the Sun up to millions or even 97 00:05:12,560 --> 00:05:17,120 Speaker 1: billions of solar masses, so many stars compacted into a 98 00:05:17,120 --> 00:05:19,719 Speaker 1: tiny little space at the center of some of these 99 00:05:19,760 --> 00:05:25,120 Speaker 1: galaxies really just mind bogglingly massive and incredibly powerful objects. Yeah, 100 00:05:25,160 --> 00:05:28,600 Speaker 1: and so black holes can be any size really in between, 101 00:05:28,720 --> 00:05:32,800 Speaker 1: and you know, from tiny, two huge, But apparently you 102 00:05:32,839 --> 00:05:34,880 Speaker 1: don't see a lot of ones in the middle out 103 00:05:34,880 --> 00:05:36,560 Speaker 1: there in the cosmos. Most of the ones that you 104 00:05:36,600 --> 00:05:39,680 Speaker 1: see out there are either kind of supernova size or 105 00:05:39,880 --> 00:05:43,479 Speaker 1: gigantic galaxy center size. Yeah, it's even more dramatic than that. 106 00:05:43,560 --> 00:05:47,120 Speaker 1: We have never seen any in between. There's not an example, 107 00:05:47,160 --> 00:05:50,479 Speaker 1: a single example of a black hole in between those two. 108 00:05:51,000 --> 00:05:53,359 Speaker 1: So we don't actually know if it's possible to have 109 00:05:53,440 --> 00:05:56,880 Speaker 1: an intermediate size black hole. Maybe the laws of physics 110 00:05:56,920 --> 00:05:59,120 Speaker 1: just don't allow it. So that's the question will be 111 00:05:59,240 --> 00:06:01,360 Speaker 1: tackling today. So to be on the program, we'll be 112 00:06:01,400 --> 00:06:10,200 Speaker 1: asking the question where are all the intermediate mass black holes? 113 00:06:10,640 --> 00:06:12,320 Speaker 1: You've gotta made it easier for me, Daniel, and just 114 00:06:12,640 --> 00:06:15,200 Speaker 1: medium mass. Well, that was going to be my next 115 00:06:15,279 --> 00:06:17,280 Speaker 1: question is what would you have called these things? Because 116 00:06:17,560 --> 00:06:21,400 Speaker 1: intermediate size black holes or intermediate mass black holes is 117 00:06:21,520 --> 00:06:23,520 Speaker 1: quite a mouthful. Yeah, I don't know, just go with 118 00:06:23,600 --> 00:06:25,839 Speaker 1: like the Starbucks rude and call them large black holes, 119 00:06:26,360 --> 00:06:28,760 Speaker 1: which are really the medium sized black holes. That's true, 120 00:06:28,760 --> 00:06:31,159 Speaker 1: but everything in the universe is enormous, right, so maybe 121 00:06:31,200 --> 00:06:35,120 Speaker 1: the Starbucks naming scheme makes sense. Yeah, large, extra large, 122 00:06:35,160 --> 00:06:39,080 Speaker 1: super large, and galectically large, cosmic large. That's right. It's 123 00:06:39,080 --> 00:06:42,000 Speaker 1: like ordering fries and McDonald's there are no more small fries, 124 00:06:42,200 --> 00:06:43,720 Speaker 1: Is that true? I think so. I think you can 125 00:06:43,720 --> 00:06:46,440 Speaker 1: only order large or extra large. I will admit not 126 00:06:46,480 --> 00:06:48,599 Speaker 1: having been to McDonald since I worked there when I 127 00:06:48,640 --> 00:06:50,680 Speaker 1: was six. And yeah, you seem to know a lot 128 00:06:50,720 --> 00:06:53,440 Speaker 1: about their menu, Danniel. I'm a member of society. I 129 00:06:53,520 --> 00:06:56,720 Speaker 1: participate in society. I read memes on the internet to 130 00:06:56,839 --> 00:06:59,240 Speaker 1: educate me about humanity. You turn your your nose up 131 00:06:59,279 --> 00:07:03,000 Speaker 1: at fast food change, sure, like everyone else in society. 132 00:07:03,080 --> 00:07:05,320 Speaker 1: But yeah, maybe I would call medium sized black holes. 133 00:07:05,360 --> 00:07:07,960 Speaker 1: You know that kind of makes sense. Yeah, you know, 134 00:07:08,040 --> 00:07:10,320 Speaker 1: as a middle child, I'm sort of sensitive to this naming. 135 00:07:10,320 --> 00:07:13,360 Speaker 1: You know, middle seems to like be defined by the others. 136 00:07:13,360 --> 00:07:16,360 Speaker 1: There's nothing like unique and identifying about being in the middle. 137 00:07:16,400 --> 00:07:18,880 Speaker 1: You're like defining yourself by what you're not instead of 138 00:07:18,880 --> 00:07:21,160 Speaker 1: by what you are. We just opened up a whole 139 00:07:21,160 --> 00:07:25,760 Speaker 1: black hole of psychological trauma. There issues there and Daniel, 140 00:07:25,920 --> 00:07:28,440 Speaker 1: your middle children out there. You know you know that well, 141 00:07:28,480 --> 00:07:30,600 Speaker 1: you have like ninety seven brothers and sisters, right, so 142 00:07:30,680 --> 00:07:32,720 Speaker 1: you you've got to understand and is this why you 143 00:07:32,760 --> 00:07:37,320 Speaker 1: started a podcast just to err on your sibling rivalry issues. Yes, 144 00:07:37,360 --> 00:07:40,240 Speaker 1: it's been a three hundred episode plan to get to 145 00:07:40,320 --> 00:07:44,120 Speaker 1: this moment exactly. All right, tell me, Daniel, tell me 146 00:07:44,120 --> 00:07:47,360 Speaker 1: about your childhood. I feel defined by my more massive 147 00:07:47,360 --> 00:07:52,600 Speaker 1: and less massive brothers. I see now you're making swipes 148 00:07:52,640 --> 00:07:56,400 Speaker 1: at their body weight there, man, I meant intellectual gravitas, 149 00:07:56,440 --> 00:07:59,560 Speaker 1: of course, yes, of course, of course, but yeah, I'll 150 00:07:59,680 --> 00:08:01,800 Speaker 1: rate that. Are talking about black holes, Daniel, and how 151 00:08:01,840 --> 00:08:04,080 Speaker 1: there aren't any real middle of the ones out there 152 00:08:04,080 --> 00:08:07,000 Speaker 1: in space. You mostly see big ones or smaller ones 153 00:08:07,080 --> 00:08:09,440 Speaker 1: the size of a few sons, And so that's the question, 154 00:08:09,440 --> 00:08:12,360 Speaker 1: where are all the intermediate mass black holes? So it's 155 00:08:12,440 --> 00:08:14,640 Speaker 1: usually we were wondering how many people out there knew 156 00:08:14,840 --> 00:08:17,679 Speaker 1: that these black holes are are missing from the universe 157 00:08:17,880 --> 00:08:20,360 Speaker 1: and where they could be. So thanks to everybody who 158 00:08:20,520 --> 00:08:24,200 Speaker 1: volunteered to answer my random questions with no preparation or 159 00:08:24,200 --> 00:08:28,120 Speaker 1: reference materials. If you'd like to participate in future episodes, 160 00:08:28,280 --> 00:08:31,080 Speaker 1: please write to me two questions at Daniel and Jorge 161 00:08:31,240 --> 00:08:34,520 Speaker 1: dot com. We love your contributions and I promise you 162 00:08:34,640 --> 00:08:36,760 Speaker 1: it's fun. So think about it for a second. Where 163 00:08:36,760 --> 00:08:39,960 Speaker 1: do you think all the medium or intermediate mass black 164 00:08:40,000 --> 00:08:43,360 Speaker 1: holes in the universe are. Here's what people had to say. 165 00:08:44,120 --> 00:08:47,280 Speaker 1: That's a good question. I think that there's no proof 166 00:08:47,320 --> 00:08:50,240 Speaker 1: that they even exist, but that they do. Maybe they 167 00:08:50,280 --> 00:08:53,679 Speaker 1: are lurking somewhere in the intergalactic space where there's just 168 00:08:53,800 --> 00:08:56,320 Speaker 1: no stuff for them to eat and growth. They don't 169 00:08:56,400 --> 00:08:59,840 Speaker 1: don't form those Christian disks, And basically the only way 170 00:08:59,840 --> 00:09:02,000 Speaker 1: that we can spot a black hole is by looking 171 00:09:02,000 --> 00:09:05,160 Speaker 1: at the Christian disk and figuring out indirectly that there 172 00:09:05,240 --> 00:09:07,520 Speaker 1: must be a black hole in the middle of it. 173 00:09:07,559 --> 00:09:09,560 Speaker 1: But if there is no a Christian disk, that we 174 00:09:09,600 --> 00:09:11,679 Speaker 1: may have a black hole that is somewhere out there, 175 00:09:11,720 --> 00:09:14,800 Speaker 1: but we just have no chance of ever spotting it. 176 00:09:14,920 --> 00:09:18,800 Speaker 1: So I would bet for intergalactic space. I know at 177 00:09:18,840 --> 00:09:22,480 Speaker 1: the center of a galaxy you get really big black holes. 178 00:09:22,520 --> 00:09:25,920 Speaker 1: I think they're called supermassive black holes. So they won't 179 00:09:25,920 --> 00:09:35,520 Speaker 1: be there, but maybe be an intergalactic space. But I'm 180 00:09:35,520 --> 00:09:38,360 Speaker 1: not sure. All right, not a lot of clarity here 181 00:09:38,400 --> 00:09:41,320 Speaker 1: from our listeners. I like the idea that maybe they're 182 00:09:41,320 --> 00:09:44,240 Speaker 1: floating out there in space and we just can't see them. 183 00:09:44,400 --> 00:09:48,080 Speaker 1: This one president said, made they're lurking in intergalactic space. Yeah, 184 00:09:48,160 --> 00:09:50,040 Speaker 1: it's a cool idea. If you're a black hole, can 185 00:09:50,120 --> 00:09:52,800 Speaker 1: you do anything else in space except lurk? Oh? Come on, 186 00:09:52,880 --> 00:09:54,800 Speaker 1: you could be very dramatic. You could swoop into us 187 00:09:54,800 --> 00:09:57,440 Speaker 1: always system and gobble it up and destroy everything. Right, 188 00:09:57,640 --> 00:10:01,000 Speaker 1: that's the opposite of lurking. That's like leaping. Yeah, but 189 00:10:01,040 --> 00:10:03,040 Speaker 1: then afterwards you go back to lurking. Well, I like 190 00:10:03,160 --> 00:10:05,880 Speaker 1: this idea because it suggests that you know, there are 191 00:10:05,920 --> 00:10:08,280 Speaker 1: things out there and intergalactic space that we don't know 192 00:10:08,360 --> 00:10:11,360 Speaker 1: about that we can't see. That it might surprise us 193 00:10:11,360 --> 00:10:14,240 Speaker 1: that basically you could hide anything out there as long 194 00:10:14,320 --> 00:10:16,840 Speaker 1: as it's dark enough. And you know, that's a reasonable point. 195 00:10:17,000 --> 00:10:19,480 Speaker 1: And I guess the real mysteries that you know there 196 00:10:19,600 --> 00:10:23,400 Speaker 1: there could be intermediate mass black holes out there, Like, 197 00:10:23,760 --> 00:10:26,560 Speaker 1: there's nothing that we know about so far that would 198 00:10:26,600 --> 00:10:29,480 Speaker 1: would prevent them. Theoretically they're possible, but you just don't 199 00:10:29,480 --> 00:10:31,440 Speaker 1: see them. Yeah. Well, that's the problem with black holes 200 00:10:31,520 --> 00:10:34,679 Speaker 1: is that you can't see them directly, right because they 201 00:10:34,720 --> 00:10:37,199 Speaker 1: are black. All you can do is see their effect 202 00:10:37,280 --> 00:10:40,640 Speaker 1: on stuff behind them or around them. And so if 203 00:10:40,679 --> 00:10:42,760 Speaker 1: you had a black hole deep in the middle of 204 00:10:42,800 --> 00:10:45,760 Speaker 1: space with nothing around it, how would you detect it, it 205 00:10:45,679 --> 00:10:49,480 Speaker 1: it would be undetectable, it would be very effectively lurking. 206 00:10:50,120 --> 00:10:52,320 Speaker 1: And so this is actually a good point. The question 207 00:10:52,360 --> 00:10:54,240 Speaker 1: that needs to know how did it get made? How 208 00:10:54,280 --> 00:10:55,920 Speaker 1: did you form a black hole out there in the 209 00:10:55,920 --> 00:10:58,800 Speaker 1: middle of space with nothing around you. Usually black holes 210 00:10:58,840 --> 00:11:01,640 Speaker 1: are made from stuff, and then there's other stuff around 211 00:11:01,720 --> 00:11:03,760 Speaker 1: that didn't get black holeified, and you can use that 212 00:11:03,800 --> 00:11:06,720 Speaker 1: to detect it. That's the mystery. And so I guess maybe, Daniel, 213 00:11:06,800 --> 00:11:10,120 Speaker 1: let's start at the beginning and let's talk about how 214 00:11:10,160 --> 00:11:12,560 Speaker 1: you would even define an intermediate black hole, like, what 215 00:11:12,679 --> 00:11:16,160 Speaker 1: is there a technical range of masses that we qualify 216 00:11:16,240 --> 00:11:20,760 Speaker 1: as intermediate Yeah, there actually is. Unfortunately for the psychology 217 00:11:20,840 --> 00:11:23,400 Speaker 1: of intermediate mass black holes, they are defined by what 218 00:11:23,520 --> 00:11:27,439 Speaker 1: they are, not they're defined by their bigger and larger siblings. Right, 219 00:11:27,920 --> 00:11:31,960 Speaker 1: So it's a black hole that's between a solar mass 220 00:11:32,040 --> 00:11:34,760 Speaker 1: black hole like one that comes from a collapsed star, 221 00:11:35,160 --> 00:11:36,680 Speaker 1: and we can talk about it, but there's definitely an 222 00:11:36,720 --> 00:11:39,520 Speaker 1: upper limit on how big that can be, because there's 223 00:11:39,520 --> 00:11:41,520 Speaker 1: an upper limit of how big a star can be. 224 00:11:42,000 --> 00:11:44,400 Speaker 1: So it has to be bigger than the black hole 225 00:11:44,440 --> 00:11:47,120 Speaker 1: that could come from a star, but then smaller than 226 00:11:47,240 --> 00:11:49,679 Speaker 1: black holes we see the center of galaxies, which is 227 00:11:49,720 --> 00:11:52,920 Speaker 1: about ten thousand or fifty thousand times the mass of 228 00:11:52,960 --> 00:11:55,640 Speaker 1: the Sun. So there's a huge range there between a 229 00:11:55,760 --> 00:11:59,360 Speaker 1: hundred and like ten thousand solar masses. We call the 230 00:11:59,520 --> 00:12:02,480 Speaker 1: intermedi a mass range for black holes. Oh, I see 231 00:12:02,520 --> 00:12:05,440 Speaker 1: there's a limit due to the sizes of stars. Exactly 232 00:12:05,480 --> 00:12:06,959 Speaker 1: what kind of black hole do you imagine when you 233 00:12:06,960 --> 00:12:09,319 Speaker 1: think about black holes? Probably are the ones that come 234 00:12:09,360 --> 00:12:12,040 Speaker 1: from when a star collapses, Right, you know that stars 235 00:12:12,040 --> 00:12:15,480 Speaker 1: are formed from gases that are collected by gravity, and 236 00:12:15,520 --> 00:12:18,679 Speaker 1: then you get fusion burning, which prevents further collapse. Right, 237 00:12:18,679 --> 00:12:21,079 Speaker 1: gravity would just go directly to a black hole if 238 00:12:21,080 --> 00:12:23,720 Speaker 1: the star didn't ignite fusion inside of it, which was 239 00:12:23,760 --> 00:12:27,160 Speaker 1: pushing out with radiation to prevent the collapse. That happens 240 00:12:27,160 --> 00:12:29,680 Speaker 1: for you know, several billion years or so until the 241 00:12:29,720 --> 00:12:33,359 Speaker 1: fuel runs out and turns into heavy ash, which accelerates 242 00:12:33,480 --> 00:12:36,720 Speaker 1: the gravitational collapse instead of preventing it, and then the 243 00:12:36,760 --> 00:12:40,280 Speaker 1: whole thing collapses into a black hole. But there's a range. 244 00:12:40,320 --> 00:12:42,560 Speaker 1: They're like, it can't collapse into a black hole if 245 00:12:42,559 --> 00:12:45,360 Speaker 1: it doesn't have enough mass. So the lower limit on 246 00:12:45,400 --> 00:12:47,679 Speaker 1: a black hole that comes from the Sun is like 247 00:12:47,880 --> 00:12:51,080 Speaker 1: ten solar masses. Smaller than that, and it collapses into 248 00:12:51,120 --> 00:12:53,600 Speaker 1: like a neutron star or something else because it can 249 00:12:53,640 --> 00:12:58,000 Speaker 1: still resist the gravitational pressure. But what about larger than that, Like, 250 00:12:58,160 --> 00:13:01,760 Speaker 1: can bigger star collapse into a bigger black hole? It can, 251 00:13:02,040 --> 00:13:04,400 Speaker 1: but you can only get up to about eighty or 252 00:13:04,559 --> 00:13:07,280 Speaker 1: ninety times the mass of the Sun. And the reason 253 00:13:07,400 --> 00:13:09,920 Speaker 1: is that you can't have a star that's much bigger 254 00:13:09,920 --> 00:13:12,520 Speaker 1: than about three hundred times the mass of the Sun. 255 00:13:12,960 --> 00:13:15,080 Speaker 1: You try to make a star bigger than that, Remember 256 00:13:15,080 --> 00:13:17,120 Speaker 1: we talked about this on an episode about the biggest 257 00:13:17,160 --> 00:13:19,840 Speaker 1: stars in the universe. Then those stars aren't stable. They 258 00:13:19,880 --> 00:13:22,920 Speaker 1: blow themselves apart because as the star gets bigger and 259 00:13:23,040 --> 00:13:25,920 Speaker 1: the inside of it gets higher pressure, and that higher 260 00:13:25,960 --> 00:13:28,960 Speaker 1: pressure means the fusion burns hotter, and so it produces 261 00:13:29,000 --> 00:13:32,679 Speaker 1: more radiation. It's very nonlinear, and so a little bit 262 00:13:32,679 --> 00:13:36,000 Speaker 1: more stuff means a much higher temperature inside, which means 263 00:13:36,120 --> 00:13:39,320 Speaker 1: radiation blowing out. So then the star literally tears itself apart. 264 00:13:39,679 --> 00:13:41,960 Speaker 1: So the biggest star you can have is about three 265 00:13:42,040 --> 00:13:44,560 Speaker 1: hundred times the mass of our Sun, which means that 266 00:13:44,559 --> 00:13:46,800 Speaker 1: there's a limit on how big a black hole you 267 00:13:46,840 --> 00:13:49,200 Speaker 1: can get that comes from a star, I see, But 268 00:13:49,240 --> 00:13:52,640 Speaker 1: the limit is smaller than the biggest star. So the 269 00:13:52,640 --> 00:13:55,440 Speaker 1: biggest stars can be three hundred times the mass of 270 00:13:55,480 --> 00:13:58,880 Speaker 1: our sign, but the ones that turn into black holes 271 00:13:59,040 --> 00:14:01,600 Speaker 1: are only the ones that go up to about eighty 272 00:14:01,640 --> 00:14:03,760 Speaker 1: times the mass of our Sun. No, no, it's because 273 00:14:03,800 --> 00:14:06,200 Speaker 1: not all the stuff in the star ends up in 274 00:14:06,240 --> 00:14:09,200 Speaker 1: the black hole, right it's tearing itself apart, and not 275 00:14:09,280 --> 00:14:11,120 Speaker 1: all of it collapses in the black hole. You still 276 00:14:11,120 --> 00:14:13,600 Speaker 1: get a huge amount of stuff outside the black hole 277 00:14:13,800 --> 00:14:15,760 Speaker 1: that it's blown out. You know. Sometimes you get like 278 00:14:15,800 --> 00:14:18,400 Speaker 1: a supernova before you get a black hole, and that 279 00:14:18,480 --> 00:14:21,040 Speaker 1: shoots a huge amount of energy and mass out into 280 00:14:21,080 --> 00:14:23,560 Speaker 1: the universe. So the process to go from star to 281 00:14:23,600 --> 00:14:26,520 Speaker 1: black holes not ad efficient, which is why three hundred 282 00:14:26,560 --> 00:14:29,680 Speaker 1: solar mass stars turned into about eighty or ninety solar 283 00:14:29,720 --> 00:14:32,880 Speaker 1: mass black holes. You're talking about the kind of the 284 00:14:32,960 --> 00:14:35,200 Speaker 1: limit of the size of the black hole that can 285 00:14:35,240 --> 00:14:37,360 Speaker 1: come from a star. But the stars usually started off 286 00:14:37,360 --> 00:14:39,280 Speaker 1: with three hundred times the mass of the Sun, and 287 00:14:39,320 --> 00:14:42,400 Speaker 1: then they collapse into eight times the mass of the Sun, 288 00:14:42,520 --> 00:14:45,360 Speaker 1: and those are very rare. Like stars that massive are 289 00:14:45,480 --> 00:14:48,480 Speaker 1: very very rare because they're very unstable and short lived. 290 00:14:48,720 --> 00:14:51,640 Speaker 1: Most stars are much much smaller than that. So most 291 00:14:51,680 --> 00:14:54,040 Speaker 1: of the stellar black holes you see out there are 292 00:14:54,040 --> 00:14:56,200 Speaker 1: in the lower end of the ten to eighty range. 293 00:14:56,320 --> 00:14:59,200 Speaker 1: Eight is like really extreme and crazy and rare. So 294 00:14:59,240 --> 00:15:01,720 Speaker 1: then that's like one kind of limit, like the biggest 295 00:15:01,760 --> 00:15:05,040 Speaker 1: stars kind of defines what the biggest black holes that 296 00:15:05,120 --> 00:15:08,760 Speaker 1: can come from the Sun with their masses exactly nicee. 297 00:15:08,760 --> 00:15:11,400 Speaker 1: And we see a lot of those out in the space, right. Yeah, 298 00:15:11,480 --> 00:15:13,680 Speaker 1: those are all over the galaxy. Every time you have 299 00:15:13,760 --> 00:15:16,280 Speaker 1: a star that's that big, its path will lead it 300 00:15:16,280 --> 00:15:18,320 Speaker 1: to become a black hole, And so those black holes 301 00:15:18,320 --> 00:15:21,240 Speaker 1: are appearing all the time. They're not rare, they're not weird, 302 00:15:21,280 --> 00:15:23,240 Speaker 1: that not unusual, and we see lots of those black 303 00:15:23,240 --> 00:15:26,400 Speaker 1: holes around the universe. That's the kind of lower range 304 00:15:26,400 --> 00:15:29,320 Speaker 1: of black holes, and then there's like the upper range 305 00:15:29,320 --> 00:15:31,560 Speaker 1: of black holes. Yeah, the black holes that we see 306 00:15:31,560 --> 00:15:34,560 Speaker 1: at the centers of galaxies are like completely different beasts. 307 00:15:34,800 --> 00:15:37,160 Speaker 1: I mean, they are similar from the general relativity point 308 00:15:37,160 --> 00:15:40,120 Speaker 1: of view in that they are very compact objects that 309 00:15:40,160 --> 00:15:43,720 Speaker 1: are very dense that have incredible gravity, but they seem 310 00:15:43,760 --> 00:15:47,280 Speaker 1: like monsters compared to these stellar black holes because they 311 00:15:47,320 --> 00:15:50,720 Speaker 1: tend to have masses like a million or a billion 312 00:15:50,840 --> 00:15:54,200 Speaker 1: times the mass of one son, and so these are 313 00:15:54,240 --> 00:15:57,800 Speaker 1: just really enormous and they really like drive the gravity 314 00:15:57,840 --> 00:15:59,760 Speaker 1: of a galaxy. They sit at the center of the 315 00:15:59,800 --> 00:16:03,360 Speaker 1: galaxy and they are you know, like one one hundreds 316 00:16:03,400 --> 00:16:05,680 Speaker 1: of the mass of the whole galaxy is in that 317 00:16:05,800 --> 00:16:08,920 Speaker 1: single black hole and it's pulling on the whole galaxy 318 00:16:08,960 --> 00:16:11,760 Speaker 1: and it's slurping everything around and it's gobbling stars at 319 00:16:11,760 --> 00:16:13,640 Speaker 1: the middle. We have one like this at the center 320 00:16:13,680 --> 00:16:16,120 Speaker 1: of our galaxy. They're pretty common, I guess, Like I 321 00:16:16,160 --> 00:16:19,560 Speaker 1: think most galaxies have a supermassive black hole at its center. 322 00:16:19,640 --> 00:16:21,560 Speaker 1: Like when you look out into space and you see, 323 00:16:22,040 --> 00:16:24,400 Speaker 1: you know, millions and millions of galaxies, most of them 324 00:16:24,440 --> 00:16:26,360 Speaker 1: have one of these giant black holes in the middle. 325 00:16:26,440 --> 00:16:29,400 Speaker 1: We don't actually know the fraction of these galaxies that 326 00:16:29,440 --> 00:16:31,760 Speaker 1: have one, And that's one of these questions, Like we 327 00:16:31,920 --> 00:16:34,640 Speaker 1: know that black holes in the center of galaxies tend 328 00:16:34,680 --> 00:16:36,960 Speaker 1: to be proportional to the mass of the galaxy. So 329 00:16:37,280 --> 00:16:40,760 Speaker 1: bigger galaxy, bigger black hole the center. Smaller galaxy, smaller 330 00:16:40,800 --> 00:16:43,000 Speaker 1: black hole the center. We don't know if they all 331 00:16:43,040 --> 00:16:45,520 Speaker 1: have black holes, like we've seen a lot without them. 332 00:16:45,600 --> 00:16:48,960 Speaker 1: We don't know the fraction of galaxies that have black holes, actually, 333 00:16:49,280 --> 00:16:50,840 Speaker 1: but it's not rare. I guess that's what I mean. 334 00:16:51,040 --> 00:16:53,760 Speaker 1: You see them often. Yeah, it's not uncommon. Absolutely, They 335 00:16:53,880 --> 00:16:56,720 Speaker 1: kind of all over the place, yes, And so what's 336 00:16:56,760 --> 00:16:58,960 Speaker 1: the range of size as we've seen for those? So 337 00:16:59,120 --> 00:17:02,800 Speaker 1: up to billion, right, like ten billion solar masses is 338 00:17:02,840 --> 00:17:05,679 Speaker 1: the biggest black hole we've ever seen. And as far 339 00:17:05,720 --> 00:17:08,120 Speaker 1: as we can tell, there's no upper limit to how 340 00:17:08,200 --> 00:17:10,399 Speaker 1: big a black hole can get. Like, you keep feeding 341 00:17:10,400 --> 00:17:12,920 Speaker 1: that thing, it'll just keep getting bigger. The limit really 342 00:17:12,960 --> 00:17:15,320 Speaker 1: is just like cann be around enough stuff and have 343 00:17:15,480 --> 00:17:17,960 Speaker 1: enough time to gobble it. On the lower end of 344 00:17:18,040 --> 00:17:21,440 Speaker 1: super massive black holes, the smallest one we've seen is 345 00:17:21,480 --> 00:17:24,920 Speaker 1: about fifty thousand times the mass of the Sun. This 346 00:17:25,000 --> 00:17:28,040 Speaker 1: is in a little mini galaxy we call these dwarf galaxies, 347 00:17:28,320 --> 00:17:31,480 Speaker 1: about three hundred forty million light years from here. The 348 00:17:31,520 --> 00:17:34,360 Speaker 1: galaxy is called r g G one eighteen. And that's 349 00:17:34,359 --> 00:17:37,360 Speaker 1: the smallest black hole we've ever seen inside a galaxy. 350 00:17:37,400 --> 00:17:40,280 Speaker 1: It's fifty thousand times the mass of the Sun. That's huge. 351 00:17:40,440 --> 00:17:44,560 Speaker 1: Imagine fifty of our sons, Yeah, and then collapsing into 352 00:17:44,560 --> 00:17:47,960 Speaker 1: a black hole like the gravity of fifty thousand suns 353 00:17:48,280 --> 00:17:50,560 Speaker 1: is nothing to be sneezed at, or if you sneezed 354 00:17:50,600 --> 00:17:52,439 Speaker 1: at it, your sneeze will get sucked up by that 355 00:17:52,480 --> 00:17:54,480 Speaker 1: black hole right away. This is not we just gets 356 00:17:54,480 --> 00:17:56,440 Speaker 1: slurped out of your nose. Probably we should call that 357 00:17:56,480 --> 00:17:58,280 Speaker 1: black hole is in tight Hey, yeah, then will be 358 00:17:58,320 --> 00:18:00,520 Speaker 1: a green black hole depending on the size of years 359 00:18:00,560 --> 00:18:03,120 Speaker 1: these we'll see. All right, Well, it seems like there 360 00:18:03,119 --> 00:18:06,440 Speaker 1: are these huge populations of black holes out there, kind 361 00:18:06,480 --> 00:18:10,560 Speaker 1: of the the star sized ones and the gassy size ones, 362 00:18:10,640 --> 00:18:13,520 Speaker 1: but maybe not so many in the middle. So let's 363 00:18:13,560 --> 00:18:17,040 Speaker 1: get into whether or not they actually exist or whether 364 00:18:17,160 --> 00:18:19,680 Speaker 1: or not we're just not seeing them. But first let's 365 00:18:19,720 --> 00:18:34,359 Speaker 1: take a quick break. All right, Daniel, we're talking about 366 00:18:34,520 --> 00:18:39,399 Speaker 1: intermediate mass black holes. Now. Is that the official names 367 00:18:39,400 --> 00:18:42,120 Speaker 1: are an acronym for that, That is the official name. 368 00:18:42,359 --> 00:18:44,840 Speaker 1: You'll see that in the literature if you search for them. 369 00:18:44,920 --> 00:18:47,040 Speaker 1: And you know, I call them I m b H. 370 00:18:47,200 --> 00:18:49,239 Speaker 1: But it sort of reminds me of I MDB, so 371 00:18:49,280 --> 00:18:50,920 Speaker 1: I think maybe we need a better name for them. 372 00:18:51,040 --> 00:18:54,040 Speaker 1: M I see. Well, they do sort of collect stars 373 00:18:54,240 --> 00:18:56,480 Speaker 1: in a way, right, I'm sure there are films of 374 00:18:56,680 --> 00:18:58,960 Speaker 1: gas clouds I'm really stretching in here. Yeah, well, we 375 00:18:58,960 --> 00:19:01,200 Speaker 1: should go look this up on the Internet movie black 376 00:19:01,240 --> 00:19:03,720 Speaker 1: Hole Database. I'm sure there is one, isn't There are 377 00:19:03,760 --> 00:19:06,280 Speaker 1: dots and physicists kind of keep track of everything and 378 00:19:06,320 --> 00:19:09,000 Speaker 1: polish it online. I don't know, but after this episode, 379 00:19:09,000 --> 00:19:11,439 Speaker 1: I'm gonna go type in i mbhdb dot com and 380 00:19:11,680 --> 00:19:15,000 Speaker 1: see if somebody owns that already. Oh man, maybe you 381 00:19:15,000 --> 00:19:18,360 Speaker 1: should have checked that before sponsoring it on the podcast. 382 00:19:19,119 --> 00:19:20,919 Speaker 1: Some family with kids are gonna look that up and 383 00:19:20,920 --> 00:19:23,600 Speaker 1: then they're gonna be like what. Alright, we're talking about 384 00:19:23,640 --> 00:19:28,000 Speaker 1: whether or not intermediate mass black holes exist because we 385 00:19:28,080 --> 00:19:30,080 Speaker 1: don't really see them out there in space. We see 386 00:19:30,280 --> 00:19:34,840 Speaker 1: the kind that are about the size of suns, a 387 00:19:34,840 --> 00:19:38,200 Speaker 1: few hundred suns that came from suns. And we talked 388 00:19:38,200 --> 00:19:40,600 Speaker 1: about black holes that are at the center of galaxies, 389 00:19:40,600 --> 00:19:43,480 Speaker 1: which are huge tens of thousands or maybe millions or 390 00:19:43,480 --> 00:19:46,479 Speaker 1: billions of times the mass of our sun out there 391 00:19:46,520 --> 00:19:48,680 Speaker 1: in the middle of galaxies. But you don't see a 392 00:19:48,680 --> 00:19:50,800 Speaker 1: lot of black holes in between out there. Yeah, there 393 00:19:50,840 --> 00:19:53,680 Speaker 1: seems to be this weird gap there, and it makes 394 00:19:53,760 --> 00:19:56,560 Speaker 1: us wonder, like, are there those black holes out there? 395 00:19:56,560 --> 00:19:58,760 Speaker 1: But we just can't see them yet, or is there 396 00:19:58,840 --> 00:20:02,360 Speaker 1: some reason why they don't even exist, like they're unstable, 397 00:20:02,480 --> 00:20:05,919 Speaker 1: or they accelerate really quickly to becoming supermassive, or they 398 00:20:05,960 --> 00:20:08,879 Speaker 1: fall apart in some way. Like anytime there's a puzzle 399 00:20:08,920 --> 00:20:11,720 Speaker 1: like that, something we don't understand, where we see something 400 00:20:11,760 --> 00:20:14,400 Speaker 1: we don't expect, or we don't see something we do expect, 401 00:20:14,680 --> 00:20:17,640 Speaker 1: that's a clue. That's an opportunity to figure out something. 402 00:20:17,680 --> 00:20:19,800 Speaker 1: It's a moment where we can learn something about the 403 00:20:19,880 --> 00:20:23,560 Speaker 1: universe because we're ready to be surprised by the data. Right. Yeah, 404 00:20:23,640 --> 00:20:25,439 Speaker 1: it would be like, you know, having a population of 405 00:20:25,480 --> 00:20:28,159 Speaker 1: people and then seeing only two sizes of people, like 406 00:20:28,280 --> 00:20:31,640 Speaker 1: not seeing you know, sort of a continuum and like 407 00:20:31,680 --> 00:20:34,280 Speaker 1: a smooth range of sizes of people. Yeah, and it 408 00:20:34,320 --> 00:20:36,440 Speaker 1: would make you wonder like how did all those tall 409 00:20:36,440 --> 00:20:39,320 Speaker 1: people get so tall? At some point they must have 410 00:20:39,359 --> 00:20:42,640 Speaker 1: been medium height, right, so where are all the future 411 00:20:42,680 --> 00:20:45,200 Speaker 1: tall people? Why are there no medium height people who 412 00:20:45,200 --> 00:20:48,200 Speaker 1: are growing into those tall people. That's basically the question 413 00:20:48,200 --> 00:20:51,720 Speaker 1: we're asking about these intermediate mass black holes. I mean, 414 00:20:51,760 --> 00:20:54,880 Speaker 1: for example, you wonder about these supermassive black holes. How 415 00:20:54,920 --> 00:20:58,040 Speaker 1: did they get supermassive? They must have started from something. 416 00:20:58,119 --> 00:21:00,919 Speaker 1: If they started from something very small, then you know, 417 00:21:00,960 --> 00:21:04,159 Speaker 1: by simple arguments, they must have at some point been 418 00:21:04,240 --> 00:21:07,320 Speaker 1: in that intermediate range. Right, Well, I guess that's one 419 00:21:07,320 --> 00:21:09,600 Speaker 1: of the mysteries, right, Like, we don't actually know where 420 00:21:09,640 --> 00:21:13,720 Speaker 1: these supermassive ones in the center of galaxies came from 421 00:21:13,800 --> 00:21:16,399 Speaker 1: or how they came to be so large. That's one mystery, right, 422 00:21:16,480 --> 00:21:18,640 Speaker 1: that's exactly the mystery. Like the argument had just made 423 00:21:18,640 --> 00:21:22,120 Speaker 1: that supermassive black holes may have started from small things 424 00:21:22,160 --> 00:21:25,080 Speaker 1: and then grown to supermassive, we don't actually know if 425 00:21:25,119 --> 00:21:28,520 Speaker 1: that's true, and we see things about supermassive black holes 426 00:21:28,560 --> 00:21:31,960 Speaker 1: that we can't explain using that idea. For example, we 427 00:21:32,040 --> 00:21:34,639 Speaker 1: look really far into the edge of the universe to 428 00:21:34,680 --> 00:21:37,960 Speaker 1: see old old galaxies, to see galaxies when they were 429 00:21:38,080 --> 00:21:41,680 Speaker 1: very very young, right like just a billion years after 430 00:21:41,720 --> 00:21:44,520 Speaker 1: the beginning of the universe, there were already galaxies, and 431 00:21:44,600 --> 00:21:49,040 Speaker 1: in those galaxies we already see super massive black holes, 432 00:21:49,280 --> 00:21:52,840 Speaker 1: like black holes that have two billion solar masses. So like, 433 00:21:53,000 --> 00:21:55,359 Speaker 1: only a billion years have passed and already you've made 434 00:21:55,400 --> 00:21:59,600 Speaker 1: stars and galaxies and supermassive black holes inside them. We 435 00:21:59,640 --> 00:22:02,040 Speaker 1: don't know how it's possible to go from nothing to 436 00:22:02,119 --> 00:22:05,280 Speaker 1: supermassive black hole in just a billion years. So it's 437 00:22:05,280 --> 00:22:07,720 Speaker 1: a mystery. How did those black holes get started. We 438 00:22:07,720 --> 00:22:10,120 Speaker 1: don't know. I see a billion years from the Big Bang, 439 00:22:10,160 --> 00:22:12,600 Speaker 1: you're saying, we already had black holes that are billions 440 00:22:12,600 --> 00:22:14,800 Speaker 1: of times the massive US Sun. Yeah, exactly, And we 441 00:22:14,880 --> 00:22:18,159 Speaker 1: can see them because those super massive black holes have 442 00:22:18,400 --> 00:22:21,560 Speaker 1: really big accretion disks around them, like this disc of 443 00:22:21,680 --> 00:22:24,440 Speaker 1: gas and dust and other stuff that's getting swirled in 444 00:22:24,800 --> 00:22:27,159 Speaker 1: it gets really hot and it glows. It sends off 445 00:22:27,200 --> 00:22:30,399 Speaker 1: a huge amount of radiation. Those are called quasars. So 446 00:22:30,520 --> 00:22:33,439 Speaker 1: we see these quasars in the very very distant universe 447 00:22:33,480 --> 00:22:36,119 Speaker 1: from the very early universe, and if you model the 448 00:22:36,200 --> 00:22:39,560 Speaker 1: formation of galaxies, it's really hard to get a black 449 00:22:39,640 --> 00:22:42,639 Speaker 1: hole that big that fast. We talked about this in 450 00:22:42,680 --> 00:22:45,040 Speaker 1: our episode about supermassive black holes, so you can dig 451 00:22:45,080 --> 00:22:47,439 Speaker 1: into that if you want more details. But very briefly, 452 00:22:47,640 --> 00:22:49,720 Speaker 1: there's sort of like a limit at how fast a 453 00:22:49,800 --> 00:22:52,600 Speaker 1: black hole can grow. It's called Eddington limit. And as 454 00:22:52,640 --> 00:22:55,000 Speaker 1: you pump more stuff near a black hole than actually 455 00:22:55,040 --> 00:22:57,520 Speaker 1: the radiation from the stuff near it pushes stuff away 456 00:22:57,600 --> 00:22:59,760 Speaker 1: from the black hole. So it's hard to feed a 457 00:22:59,800 --> 00:23:02,200 Speaker 1: black back hole fast enough to have a grow to 458 00:23:02,280 --> 00:23:04,560 Speaker 1: be that big that quickly. So it's a mystery. We 459 00:23:04,640 --> 00:23:07,560 Speaker 1: don't know if these black holes actually started from something 460 00:23:07,640 --> 00:23:10,880 Speaker 1: small and then passed through this intermediate mass black hole 461 00:23:10,960 --> 00:23:13,919 Speaker 1: region and then became supermassive black hole, or if they 462 00:23:13,960 --> 00:23:16,119 Speaker 1: somehow skipped it. Could they have just you know, drunken 463 00:23:16,160 --> 00:23:20,160 Speaker 1: a lot of strong coffee or Italian style and black espresso, 464 00:23:20,640 --> 00:23:23,040 Speaker 1: or maybe American style boxes of cookies. You know, there 465 00:23:23,080 --> 00:23:25,760 Speaker 1: are other ideas to explain the supermassive black holes, like, 466 00:23:25,960 --> 00:23:29,960 Speaker 1: for example, maybe there were black holes that begin in 467 00:23:30,040 --> 00:23:33,840 Speaker 1: the very beginning of the universe, before there were even particles, 468 00:23:33,960 --> 00:23:36,680 Speaker 1: before they were stars, before there was even really matter. 469 00:23:37,320 --> 00:23:40,600 Speaker 1: Maybe there were these primordial black holes right because the 470 00:23:40,840 --> 00:23:43,840 Speaker 1: Big Band was pretty crazy, I imagine, or at least 471 00:23:43,960 --> 00:23:46,159 Speaker 1: how the universe was before the Big Bang, and you know, 472 00:23:46,280 --> 00:23:49,840 Speaker 1: things were pretty chaotic and crazy, and so maybe why not, 473 00:23:50,000 --> 00:23:52,119 Speaker 1: why couldn't you just have black holes form and that 474 00:23:52,280 --> 00:23:55,760 Speaker 1: kind of primordial high energy soup. Yeah, you could have. 475 00:23:56,320 --> 00:23:58,200 Speaker 1: And if you did that, then you could have gotten 476 00:23:58,240 --> 00:24:01,360 Speaker 1: a bunch of really tiny black holes and intermediate mass 477 00:24:01,400 --> 00:24:04,439 Speaker 1: black holes and maybe even supermassive black holes, or big 478 00:24:04,560 --> 00:24:06,919 Speaker 1: enough at least to become a seed which later turned 479 00:24:07,000 --> 00:24:11,159 Speaker 1: into these early supermassive black holes. And so it might 480 00:24:11,280 --> 00:24:14,280 Speaker 1: be possible that the supermassive black holes were seeing were 481 00:24:14,440 --> 00:24:17,840 Speaker 1: never intermediate mass, that they formed like suddenly during the 482 00:24:17,920 --> 00:24:21,720 Speaker 1: Big Bang, already fifty thousand solar masses and then just 483 00:24:21,880 --> 00:24:24,560 Speaker 1: grew to a billion masses. So the point there is 484 00:24:24,920 --> 00:24:27,760 Speaker 1: just because you have really big black holes doesn't mean 485 00:24:27,880 --> 00:24:30,639 Speaker 1: they were once medium sized. Right. It's it's kind of 486 00:24:30,680 --> 00:24:33,159 Speaker 1: like having a birthmark, like a mall you're born with, 487 00:24:34,200 --> 00:24:36,480 Speaker 1: not a mall of that shows up later. Yeah, and 488 00:24:37,000 --> 00:24:38,480 Speaker 1: there's a lot of really fun stuff. We have a 489 00:24:38,520 --> 00:24:40,960 Speaker 1: whole episode about primordial black holes, which is a really 490 00:24:41,000 --> 00:24:44,200 Speaker 1: fascinating topic because they might actually be real and out there, 491 00:24:44,240 --> 00:24:46,159 Speaker 1: and some people still think they might account for the 492 00:24:46,320 --> 00:24:49,119 Speaker 1: dark matter. So it's a really fun topic. The problem 493 00:24:49,200 --> 00:24:51,320 Speaker 1: with primordial black holes is that if you make them, 494 00:24:51,560 --> 00:24:53,800 Speaker 1: you expect to make them out all sizes, like really 495 00:24:53,840 --> 00:24:56,200 Speaker 1: big ones and then also really little ones and the 496 00:24:56,280 --> 00:24:58,680 Speaker 1: smaller ones. We should see those, and we should see 497 00:24:58,720 --> 00:25:02,520 Speaker 1: them evaporating, because from small black holes evaporate and they 498 00:25:02,600 --> 00:25:05,359 Speaker 1: give off radiation and as they give off radiation, they 499 00:25:05,400 --> 00:25:07,080 Speaker 1: get smaller, and as they get smaller, they give off 500 00:25:07,119 --> 00:25:10,440 Speaker 1: more radiation, so they would evaporate very brightly and we 501 00:25:10,480 --> 00:25:13,600 Speaker 1: should see that, and we haven't. So there's some skepticism 502 00:25:13,640 --> 00:25:16,520 Speaker 1: about whether primordial black holes are a thing. You're saying, like, 503 00:25:16,600 --> 00:25:19,000 Speaker 1: at the beating of the universe, we don't see evidence 504 00:25:19,080 --> 00:25:21,240 Speaker 1: for those little tiny black holes for me. Yeah, we 505 00:25:21,280 --> 00:25:22,919 Speaker 1: don't see evans for it. It doesn't mean that they 506 00:25:22,960 --> 00:25:25,399 Speaker 1: didn't happen, but we don't see evidence for it. So 507 00:25:25,760 --> 00:25:29,439 Speaker 1: if primordial black holes are the explanation for super massive 508 00:25:29,480 --> 00:25:32,120 Speaker 1: black holes, you need some reason why they basically only 509 00:25:32,200 --> 00:25:34,239 Speaker 1: got made on the larger size and they didn't make 510 00:25:34,320 --> 00:25:36,440 Speaker 1: littler ones that we would also be seen. But that's 511 00:25:36,480 --> 00:25:39,080 Speaker 1: not the only problem with that theory, right that Also 512 00:25:39,160 --> 00:25:41,399 Speaker 1: the theory is that even if you had started with 513 00:25:41,520 --> 00:25:44,120 Speaker 1: tiny black holes from the Big Bang, there's no way 514 00:25:44,119 --> 00:25:47,639 Speaker 1: they could have grown that big to what we see today. Yeah, well, 515 00:25:47,680 --> 00:25:50,080 Speaker 1: you need to make primordial black holes to be pretty big, 516 00:25:50,440 --> 00:25:53,200 Speaker 1: so you need to start from pretty large primordial black 517 00:25:53,240 --> 00:25:55,879 Speaker 1: holes so that they could be big enough to seed 518 00:25:56,320 --> 00:25:59,439 Speaker 1: the supermassive black holes we see today. You'd make them 519 00:25:59,480 --> 00:26:01,760 Speaker 1: at all ales in the Big Bang from tiny to 520 00:26:01,880 --> 00:26:03,600 Speaker 1: really massive. And I see. And the problem is that 521 00:26:03,680 --> 00:26:06,679 Speaker 1: we don't see evidence for those large seeds or what well, 522 00:26:06,720 --> 00:26:09,240 Speaker 1: that would explain the supermassive black holes. But we would 523 00:26:09,280 --> 00:26:11,280 Speaker 1: also expect to see the little ones, and we don't 524 00:26:11,320 --> 00:26:13,520 Speaker 1: see the little ones anywhere. Like the little ones. We 525 00:26:13,560 --> 00:26:16,479 Speaker 1: should see those evaporating all over the galaxy like they 526 00:26:16,480 --> 00:26:18,520 Speaker 1: should last, you know, a few billion years, and they 527 00:26:18,520 --> 00:26:21,320 Speaker 1: should be evaporating in these bright flashes of light as 528 00:26:21,400 --> 00:26:24,280 Speaker 1: they disappear. But we don't see that. So that means 529 00:26:24,400 --> 00:26:27,520 Speaker 1: that there aren't little primordial black holes. Doesn't mean there 530 00:26:27,560 --> 00:26:29,840 Speaker 1: weren't really big primordial black holes, but it means there 531 00:26:29,840 --> 00:26:32,480 Speaker 1: weren't really little primorial black holes. And that means that 532 00:26:32,520 --> 00:26:35,080 Speaker 1: it's a little bit more complicated to explain. Oh, I 533 00:26:35,240 --> 00:26:37,600 Speaker 1: see right, because we can see back in time. Right 534 00:26:37,640 --> 00:26:39,440 Speaker 1: when we look at into space, we can sort of 535 00:26:39,520 --> 00:26:42,720 Speaker 1: see back in time towards what was there close to 536 00:26:42,800 --> 00:26:45,320 Speaker 1: the Big Bang. Exactly, we do literally see back in 537 00:26:45,440 --> 00:26:47,840 Speaker 1: time because light takes time to get here from Earth. 538 00:26:47,920 --> 00:26:50,879 Speaker 1: We're seeing now what happened a million or a billion, 539 00:26:51,040 --> 00:26:53,280 Speaker 1: or five or ten billion years ago. As we look 540 00:26:53,320 --> 00:26:55,920 Speaker 1: deeper into the universe. It's really pretty awesome that we 541 00:26:55,960 --> 00:26:58,280 Speaker 1: can look backwards in time. But there are also other 542 00:26:58,400 --> 00:27:00,800 Speaker 1: ways that you could form these sue for massive black 543 00:27:00,880 --> 00:27:05,359 Speaker 1: holes without going through the intermediate mass black hole route right. 544 00:27:05,440 --> 00:27:07,600 Speaker 1: You could, for example, even without forming them in the 545 00:27:07,640 --> 00:27:10,720 Speaker 1: Big Bang, you could have this scenario where super massive 546 00:27:10,720 --> 00:27:14,080 Speaker 1: black holes formed directly from clouds of gas and dust. 547 00:27:14,280 --> 00:27:16,800 Speaker 1: It's called direct collapse. They never stopped and become a 548 00:27:16,880 --> 00:27:19,000 Speaker 1: star and burn for billions of years. First they just 549 00:27:19,080 --> 00:27:21,480 Speaker 1: go straight to black hole. Really, you can do that. 550 00:27:21,640 --> 00:27:25,080 Speaker 1: You can just form a black hole without igniting and 551 00:27:25,200 --> 00:27:27,720 Speaker 1: with fusion and everything. It's a theory. We've never proven 552 00:27:27,760 --> 00:27:29,560 Speaker 1: it and we've never seen one, but it's a theory 553 00:27:29,600 --> 00:27:32,840 Speaker 1: that people can't rule out. If you have enough stuff, 554 00:27:32,920 --> 00:27:36,280 Speaker 1: like a really big blob of stuff, then it collapses 555 00:27:36,359 --> 00:27:39,400 Speaker 1: fast enough the fusion doesn't have a chance to slow 556 00:27:39,480 --> 00:27:41,600 Speaker 1: it down and repel it, and it just goes straight 557 00:27:41,680 --> 00:27:44,040 Speaker 1: to black hole. And you can sort of simulate it, 558 00:27:44,200 --> 00:27:46,480 Speaker 1: and that can actually happen, like if you like the 559 00:27:46,600 --> 00:27:50,879 Speaker 1: clouds somehow takes up enough speed compressing that it starts 560 00:27:50,920 --> 00:27:52,840 Speaker 1: to night in the middle, but it's too late. There's 561 00:27:52,840 --> 00:27:55,119 Speaker 1: more stuff falling in and then poof, it becomes a 562 00:27:55,160 --> 00:27:57,840 Speaker 1: black hole. Yeah, grand gravity wins. And again it's still 563 00:27:57,880 --> 00:28:00,320 Speaker 1: just a theory, but the calculations check out out. We've 564 00:28:00,359 --> 00:28:02,320 Speaker 1: never seen when we don't have direct evidence for it. 565 00:28:02,440 --> 00:28:05,600 Speaker 1: But it's a way to potentially explain how these supermassive 566 00:28:05,640 --> 00:28:08,960 Speaker 1: black holes got started and then had a chance to grow. 567 00:28:09,320 --> 00:28:11,360 Speaker 1: And it would be another way to have really big 568 00:28:11,440 --> 00:28:14,639 Speaker 1: black holes without ever going through this middle phase, this 569 00:28:14,800 --> 00:28:17,720 Speaker 1: awkward teenage years of the black hole, when you head 570 00:28:17,760 --> 00:28:21,240 Speaker 1: between a hundred and ten thousand solar masses. They could 571 00:28:21,280 --> 00:28:24,280 Speaker 1: have directly collapsed to something really really big fifty tho 572 00:28:24,520 --> 00:28:26,920 Speaker 1: solar masses and then just kept growing from there. Isn't 573 00:28:26,920 --> 00:28:29,880 Speaker 1: there another theory that these supermassive black holes come from 574 00:28:30,280 --> 00:28:34,320 Speaker 1: smaller black holes colliding and merging into bigger and bigger ones. 575 00:28:34,520 --> 00:28:37,240 Speaker 1: For sure, But that takes a long time, right. If 576 00:28:37,320 --> 00:28:40,120 Speaker 1: you think that these big black holes came from really 577 00:28:40,160 --> 00:28:43,720 Speaker 1: tiny black holes, then they spend a long time in 578 00:28:43,800 --> 00:28:47,120 Speaker 1: the tiny stage, right because the gravity is proportional to 579 00:28:47,200 --> 00:28:48,920 Speaker 1: the size of it. And so if you start from 580 00:28:49,000 --> 00:28:52,040 Speaker 1: just like one stellar black hole and then at another 581 00:28:52,120 --> 00:28:54,560 Speaker 1: and at another, there's not enough time in the universe 582 00:28:54,640 --> 00:28:58,840 Speaker 1: to get up to billions of solar masses. That's the problem, right, 583 00:28:58,920 --> 00:29:01,040 Speaker 1: because I guess you know it thinks in space on 584 00:29:01,240 --> 00:29:03,200 Speaker 1: just like collapse head on. Right, they have to circle 585 00:29:03,240 --> 00:29:05,920 Speaker 1: each other for a while, you have to date, you know, 586 00:29:06,280 --> 00:29:09,000 Speaker 1: you have to go grab some coffee, eat some cookies, 587 00:29:09,080 --> 00:29:11,440 Speaker 1: and then eventually they collapse into each other. Right, that's 588 00:29:11,480 --> 00:29:13,400 Speaker 1: kind of the idea, Like things just don't running to 589 00:29:13,480 --> 00:29:15,320 Speaker 1: each other out there in space. Yeah, it's not like 590 00:29:15,440 --> 00:29:17,720 Speaker 1: some huge cosmic kid out there is trying to build, 591 00:29:17,960 --> 00:29:20,080 Speaker 1: you know, a supermassive black hole by sticking the black 592 00:29:20,120 --> 00:29:22,600 Speaker 1: hole legos together. It's got to happen. And for that 593 00:29:22,720 --> 00:29:24,040 Speaker 1: to happen, the things have to be in the right 594 00:29:24,120 --> 00:29:26,520 Speaker 1: arrangement and they have to collapse into each other. And 595 00:29:26,600 --> 00:29:29,080 Speaker 1: it gets easier as your black hole gets bitter because 596 00:29:29,120 --> 00:29:31,240 Speaker 1: it's more powerful and it can gobble stuff, so like 597 00:29:31,680 --> 00:29:34,520 Speaker 1: the sphere of its influence grows and where it can 598 00:29:34,600 --> 00:29:37,320 Speaker 1: eat from grows, so then it grows more quickly. But 599 00:29:37,400 --> 00:29:39,120 Speaker 1: that's why a black hole that starts from a really 600 00:29:39,240 --> 00:29:42,880 Speaker 1: small object spends most of its time small before it 601 00:29:42,920 --> 00:29:46,080 Speaker 1: accelerates its growth near the later phase. So we would 602 00:29:46,120 --> 00:29:48,400 Speaker 1: see those and they would take too long to get 603 00:29:48,440 --> 00:29:51,320 Speaker 1: to the supermassive black hole stage, so they can't explain 604 00:29:51,440 --> 00:29:55,240 Speaker 1: all the really old, huge black holes that we see, right, 605 00:29:55,360 --> 00:29:58,400 Speaker 1: and so that's the big mysteries that we know where 606 00:29:58,640 --> 00:30:01,760 Speaker 1: the smaller size black holes come from. They come from stars, 607 00:30:01,960 --> 00:30:05,200 Speaker 1: and then we see a bunch of the huge black 608 00:30:05,240 --> 00:30:08,240 Speaker 1: holes in the center of galaxies, but we don't see 609 00:30:08,320 --> 00:30:09,960 Speaker 1: the ones in between, and we don't know how the 610 00:30:10,000 --> 00:30:12,400 Speaker 1: big ones got as big as they did, Yeah, exactly. 611 00:30:12,760 --> 00:30:15,520 Speaker 1: We don't know those big ones were once intermediate size, 612 00:30:15,560 --> 00:30:18,280 Speaker 1: and we can't see any examples of the intermediate sized ones, 613 00:30:18,320 --> 00:30:21,000 Speaker 1: which seems like a head scratcher, right. Yeah, it's kind 614 00:30:21,000 --> 00:30:22,640 Speaker 1: of like a double mystery, like we don't know how 615 00:30:22,680 --> 00:30:25,240 Speaker 1: they got so big, and also we don't see any 616 00:30:25,280 --> 00:30:28,000 Speaker 1: of the middle ones. Yeah, and we'd love to unravel 617 00:30:28,080 --> 00:30:30,600 Speaker 1: that mystery. We'd love to understand how these supermassive black 618 00:30:30,640 --> 00:30:33,800 Speaker 1: holes form. And so finding one like when it was 619 00:30:33,880 --> 00:30:36,360 Speaker 1: a child might really give us a clue to how 620 00:30:36,440 --> 00:30:38,680 Speaker 1: they formed, or if we could prove that they never 621 00:30:38,760 --> 00:30:42,040 Speaker 1: were children, they were like fully born as supermassive black holes, 622 00:30:42,120 --> 00:30:44,840 Speaker 1: then one fell swoop that would also be fascinating. That 623 00:30:45,000 --> 00:30:47,720 Speaker 1: is a possibility, is that maybe they were made super 624 00:30:47,800 --> 00:30:50,480 Speaker 1: big in the big bank as primordial black holes or 625 00:30:50,560 --> 00:30:54,000 Speaker 1: through direct collapse. There are some mechanisms to make these 626 00:30:54,040 --> 00:30:57,640 Speaker 1: things and skip that intermediate phase. Right, That would make sense, right, 627 00:30:57,760 --> 00:31:01,200 Speaker 1: you know, to have their own proper origin story that 628 00:31:01,360 --> 00:31:04,400 Speaker 1: doesn't involve growing. Yeah, it does make sense. But you know, 629 00:31:04,560 --> 00:31:08,400 Speaker 1: galaxies come in all sizes. There are really big galaxies 630 00:31:08,480 --> 00:31:11,000 Speaker 1: and there are smaller galaxies, and it goes down to 631 00:31:11,160 --> 00:31:14,000 Speaker 1: pretty small like galaxies can be down to just a 632 00:31:14,120 --> 00:31:19,000 Speaker 1: few thousand stars. And so if black holes inside galaxies 633 00:31:19,000 --> 00:31:21,440 Speaker 1: are proportional to the mass of the black hole, and 634 00:31:21,480 --> 00:31:23,760 Speaker 1: again we don't know that, we've just seen that relationship 635 00:31:23,800 --> 00:31:26,560 Speaker 1: for larger galaxies, then it stands to reason that these 636 00:31:26,600 --> 00:31:30,800 Speaker 1: smaller galaxies should have smaller black holes inside them. Well 637 00:31:30,880 --> 00:31:33,560 Speaker 1: that's the mystery, and so let's talk about now how 638 00:31:33,720 --> 00:31:36,320 Speaker 1: we could find them or are people looking for these 639 00:31:36,400 --> 00:31:39,400 Speaker 1: medium sized black holes and is it theoretically possible to 640 00:31:39,440 --> 00:31:42,080 Speaker 1: see them or that they can exist. So let's get 641 00:31:42,080 --> 00:31:57,560 Speaker 1: into that, but first let's take another quick break. Alright, 642 00:31:57,600 --> 00:32:01,280 Speaker 1: we're talking about the ignored middle child, i'll black holes 643 00:32:01,400 --> 00:32:03,880 Speaker 1: of the universe, And I know this is a personal 644 00:32:04,000 --> 00:32:06,600 Speaker 1: topic for you. Daniel I'm sticking up for these black holes. 645 00:32:07,960 --> 00:32:10,320 Speaker 1: You're just trying to make them the cool ones. I think, Yeah, 646 00:32:10,920 --> 00:32:12,760 Speaker 1: we're like, who cares about? The little ones are the 647 00:32:12,840 --> 00:32:15,800 Speaker 1: big ones, They get all the attention. The cool ones 648 00:32:15,840 --> 00:32:17,360 Speaker 1: are the ones that you know, sit in the back 649 00:32:17,520 --> 00:32:21,480 Speaker 1: and plot their revenge with a podcast years later, decades, 650 00:32:21,920 --> 00:32:28,040 Speaker 1: decades into making This is My Revenge. No, set the 651 00:32:28,080 --> 00:32:31,160 Speaker 1: record straight. I love my brothers. They're wonderful and they're supportive, 652 00:32:31,320 --> 00:32:34,920 Speaker 1: and we're all very good friends. Right, Yes, did that 653 00:32:35,000 --> 00:32:39,600 Speaker 1: not sound sincere I meant it to. That sounded a 654 00:32:39,640 --> 00:32:41,520 Speaker 1: little tacked on at the end, But hey, you know, 655 00:32:42,040 --> 00:32:45,920 Speaker 1: I know how it goes your lawyer or a therapist. 656 00:32:46,240 --> 00:32:50,440 Speaker 1: Is there supposed to be a difference? Really? All right, well, 657 00:32:50,480 --> 00:32:53,280 Speaker 1: let's get into this mystery of the medium sized black holes. 658 00:32:53,320 --> 00:32:55,640 Speaker 1: We can't see them anywhere, now, Daniel. Do you think 659 00:32:55,720 --> 00:32:57,600 Speaker 1: we don't see them because we can't see them or 660 00:32:57,600 --> 00:32:59,880 Speaker 1: because they don't exist? That's the question. We don't know 661 00:33:00,080 --> 00:33:04,560 Speaker 1: the answer too, because frustratingly, smaller black holes are harder 662 00:33:04,680 --> 00:33:07,400 Speaker 1: to see. Like, one thing we're pretty good at is 663 00:33:07,480 --> 00:33:10,200 Speaker 1: figuring out what we're good at, and we're good at 664 00:33:10,240 --> 00:33:12,880 Speaker 1: seeing really big black holes because we can see them 665 00:33:12,920 --> 00:33:15,840 Speaker 1: affect how stars move in the center of galaxies, or 666 00:33:15,920 --> 00:33:19,120 Speaker 1: sometimes they have like huge quasars. We also know that 667 00:33:19,200 --> 00:33:22,720 Speaker 1: we're not very good at seeing smaller black holes, and 668 00:33:22,800 --> 00:33:25,000 Speaker 1: so we haven't seen any. But we also know that 669 00:33:25,080 --> 00:33:27,160 Speaker 1: we're not great at spotting them, so that leaves the 670 00:33:27,240 --> 00:33:29,520 Speaker 1: questions sort of up in the air. Right. Yeah, even 671 00:33:29,560 --> 00:33:31,840 Speaker 1: the ones that come from giants sons, they're kind of 672 00:33:31,880 --> 00:33:34,960 Speaker 1: hard to spot in space, right, It's not like they glow, 673 00:33:35,080 --> 00:33:39,240 Speaker 1: they're transparent invisible, and space is pretty dark, and maybe 674 00:33:39,280 --> 00:33:40,960 Speaker 1: they're not heavy enough to kind of like have a 675 00:33:41,000 --> 00:33:43,120 Speaker 1: big impact in the stars around them. Yeah, you have 676 00:33:43,280 --> 00:33:45,160 Speaker 1: to infer them. You have to be lucky. So you 677 00:33:45,280 --> 00:33:48,960 Speaker 1: have to see for example, gravitational lensing where the light 678 00:33:49,120 --> 00:33:51,480 Speaker 1: that passes near them gets bent as if there was 679 00:33:51,520 --> 00:33:54,320 Speaker 1: a huge invisible mass of stuff there, and you know, 680 00:33:54,520 --> 00:33:56,360 Speaker 1: you have to know that it's really compact and dense, 681 00:33:56,400 --> 00:33:58,480 Speaker 1: so it's not just like some big diffuse cloud or 682 00:33:58,560 --> 00:34:01,040 Speaker 1: dark matter, or you have to see their impact on 683 00:34:01,200 --> 00:34:04,080 Speaker 1: other nearby stars with nothing else to explain it. So 684 00:34:04,160 --> 00:34:07,080 Speaker 1: it's usually just like a process of elimination. We see 685 00:34:07,200 --> 00:34:09,320 Speaker 1: something happening in space and we can't explain it in 686 00:34:09,400 --> 00:34:12,640 Speaker 1: any other way other than a black hole. It's pretty rare. 687 00:34:12,719 --> 00:34:15,640 Speaker 1: You get very direct evidence of a black hole though sometimes, 688 00:34:15,880 --> 00:34:17,880 Speaker 1: and that's usually in the center of a galaxy, when 689 00:34:17,880 --> 00:34:21,279 Speaker 1: they're really big and there's like quasar emissions and other 690 00:34:21,360 --> 00:34:23,719 Speaker 1: stars moving very close to them. Have we seen the 691 00:34:23,800 --> 00:34:26,520 Speaker 1: smaller black holes, like, is there a catalog of them 692 00:34:26,640 --> 00:34:29,640 Speaker 1: or are they still kind of theoretical that they exist? Now, 693 00:34:29,719 --> 00:34:32,879 Speaker 1: we have definitely observed stellar mass black holes. Absolutely, we've 694 00:34:32,880 --> 00:34:35,360 Speaker 1: seen their gravitational lensing, we have seen their effect on 695 00:34:35,480 --> 00:34:37,880 Speaker 1: other bodies. In fact, we did a whole fun podcast 696 00:34:37,920 --> 00:34:40,759 Speaker 1: episode about the history of how people became convinced that 697 00:34:40,920 --> 00:34:43,560 Speaker 1: was not just a mathematical concept, but they were real 698 00:34:43,719 --> 00:34:45,520 Speaker 1: and they were out there, and the first one was 699 00:34:45,600 --> 00:34:48,120 Speaker 1: at the center of our galaxy is supermassive black hole. 700 00:34:48,440 --> 00:34:51,239 Speaker 1: But then later we observed a few candidates whereas a 701 00:34:51,280 --> 00:34:53,960 Speaker 1: stellar mass black hole m I see. And so we 702 00:34:54,080 --> 00:34:55,880 Speaker 1: see those, and we sort of see them in our 703 00:34:55,920 --> 00:34:58,480 Speaker 1: neighborhood kind of in our galaxy at least, but we 704 00:34:58,560 --> 00:35:00,959 Speaker 1: don't see the ones that are bigger, which you would 705 00:35:00,960 --> 00:35:03,279 Speaker 1: think we'd see, right because they are more massive and 706 00:35:03,360 --> 00:35:06,279 Speaker 1: so they would have more more of an impact on 707 00:35:06,400 --> 00:35:09,120 Speaker 1: the motion of stars around them, but we don't see them. 708 00:35:09,280 --> 00:35:11,600 Speaker 1: We see them if they're big enough, right, A million 709 00:35:11,760 --> 00:35:14,560 Speaker 1: mass black hole has a big impact on what's going 710 00:35:14,600 --> 00:35:16,719 Speaker 1: on in the center of galaxy. And so we can 711 00:35:16,840 --> 00:35:19,239 Speaker 1: look at those galaxies and we can study the motion 712 00:35:19,320 --> 00:35:21,440 Speaker 1: of stars in their center, and we can infer the 713 00:35:21,560 --> 00:35:23,800 Speaker 1: presence of a black hole, just like we do for 714 00:35:23,920 --> 00:35:27,560 Speaker 1: our galaxy. The problem is that smaller galaxies have fewer 715 00:35:27,640 --> 00:35:30,400 Speaker 1: stars and smaller black holes. So if you're looking at 716 00:35:30,440 --> 00:35:32,919 Speaker 1: a smaller galaxy like a dwarf galaxy, and you're trying 717 00:35:32,960 --> 00:35:35,160 Speaker 1: to understand does the motion of the stars tell me 718 00:35:35,280 --> 00:35:38,440 Speaker 1: there's some invisible sorts of gravity there? Then these are 719 00:35:38,560 --> 00:35:40,839 Speaker 1: small galaxies. It's sort of hard to just like get 720 00:35:40,920 --> 00:35:44,160 Speaker 1: the angular resolution you need to tell the motion of 721 00:35:44,239 --> 00:35:47,839 Speaker 1: the stars in these far away small galaxies. Oh, I see. 722 00:35:48,000 --> 00:35:51,320 Speaker 1: So you're saying that maybe they are there in smaller galaxies, 723 00:35:51,360 --> 00:35:53,560 Speaker 1: but we just can't tell. We know that we can't 724 00:35:53,600 --> 00:35:55,480 Speaker 1: see them. We know that if they were there, we 725 00:35:55,600 --> 00:35:57,680 Speaker 1: could not see them today. We just do not have 726 00:35:58,160 --> 00:36:01,920 Speaker 1: the resolution in current tell lescopes to see these stars 727 00:36:02,040 --> 00:36:05,160 Speaker 1: moving well enough to answer the question is there an 728 00:36:05,200 --> 00:36:07,960 Speaker 1: intermediate mass black hole there, Like, we just don't have 729 00:36:08,080 --> 00:36:10,440 Speaker 1: the eyeballs that we need. So they could be out there, 730 00:36:10,480 --> 00:36:12,120 Speaker 1: then it could be out there. We know that we 731 00:36:12,160 --> 00:36:14,200 Speaker 1: couldn't see them if they were there, so they could 732 00:36:14,239 --> 00:36:16,279 Speaker 1: be out there. And we have big plans like the 733 00:36:16,360 --> 00:36:20,239 Speaker 1: thirty meter telescope or the extremely large telescope. These are 734 00:36:20,280 --> 00:36:22,280 Speaker 1: things that are being built now and will come online 735 00:36:22,280 --> 00:36:25,640 Speaker 1: in tennish years. These will have much better resolution. They'll 736 00:36:25,680 --> 00:36:28,600 Speaker 1: be able to like get crisper pictures of these small 737 00:36:28,719 --> 00:36:31,400 Speaker 1: galaxies that are far away, to get a sense for 738 00:36:31,440 --> 00:36:34,279 Speaker 1: the motion of the stars near their center and tell 739 00:36:34,400 --> 00:36:36,719 Speaker 1: us if there's an intermediate black hole there or not. 740 00:36:37,040 --> 00:36:39,400 Speaker 1: We just can't see them today, and we haven't been 741 00:36:39,480 --> 00:36:42,239 Speaker 1: able to see them, right, Like, we know that they've 742 00:36:42,280 --> 00:36:45,200 Speaker 1: been kind of hiding from us if they exist, which 743 00:36:45,239 --> 00:36:47,080 Speaker 1: we don't know if they exist. Yeah, we know they've 744 00:36:47,080 --> 00:36:49,440 Speaker 1: been hiding from us. But that's just one technique to 745 00:36:49,680 --> 00:36:52,200 Speaker 1: see intermediate mass black holes, right is to look for 746 00:36:52,280 --> 00:36:55,279 Speaker 1: the motion of the stars near their center. There are 747 00:36:55,400 --> 00:36:57,440 Speaker 1: other techniques that people have been trying as well. What 748 00:36:57,680 --> 00:37:00,319 Speaker 1: are those techniques? Well, another one is not to look 749 00:37:00,440 --> 00:37:03,319 Speaker 1: at galaxies at all, but to look for other kinds 750 00:37:03,360 --> 00:37:05,360 Speaker 1: of things. Is this stuff out there in the universe 751 00:37:05,400 --> 00:37:08,800 Speaker 1: called globular clusters. We had a whole fun podcast EFFS 752 00:37:08,960 --> 00:37:11,480 Speaker 1: just about what are globular clusters and how much fun 753 00:37:11,560 --> 00:37:13,880 Speaker 1: it is to say that word. But these are weird 754 00:37:14,040 --> 00:37:18,560 Speaker 1: spherical collections of stars, and because they're much smaller than galaxies, 755 00:37:18,640 --> 00:37:22,080 Speaker 1: people think they might have intermediate mass black holes in them. 756 00:37:22,239 --> 00:37:24,920 Speaker 1: The upside is that they're much closer than other galaxies. 757 00:37:24,920 --> 00:37:27,400 Speaker 1: They tend to be like orbiting our galaxy. Like we 758 00:37:27,520 --> 00:37:31,360 Speaker 1: have several globular clusters orbiting our galaxy, so they're nearby, 759 00:37:31,520 --> 00:37:34,319 Speaker 1: so we can like take pretty good pictures and see 760 00:37:34,360 --> 00:37:36,880 Speaker 1: the motions of the stars inside them and get a 761 00:37:36,960 --> 00:37:39,239 Speaker 1: sense for whether or not there's an intermediate mass black 762 00:37:39,320 --> 00:37:43,319 Speaker 1: hole inside. Oh, I see these clusters. They're busier basically, right, 763 00:37:43,400 --> 00:37:45,239 Speaker 1: They have more stuff to them, more stars, and so 764 00:37:45,360 --> 00:37:47,840 Speaker 1: you would be able to maybe see the effects of 765 00:37:47,920 --> 00:37:50,399 Speaker 1: a medium black hole in them. Yeah, and they're much 766 00:37:50,480 --> 00:37:53,040 Speaker 1: closer than these other dwarf galaxies which tend to be 767 00:37:53,080 --> 00:37:55,320 Speaker 1: pretty distant, and so we would have a shot. The 768 00:37:55,400 --> 00:37:58,240 Speaker 1: problem is that these globular clusters aren't as tightly packed 769 00:37:58,320 --> 00:38:01,200 Speaker 1: sometimes as a dwarf galaxy, and so the speeds of 770 00:38:01,280 --> 00:38:04,160 Speaker 1: the stars are slower, so it's hard to tell if 771 00:38:04,200 --> 00:38:06,680 Speaker 1: there's an intermediate mass black hole. There are not. You 772 00:38:06,719 --> 00:38:09,200 Speaker 1: need to take pictures over like decades to see the 773 00:38:09,320 --> 00:38:11,600 Speaker 1: motions of those stars and infer it. And there's a 774 00:38:11,680 --> 00:38:14,839 Speaker 1: few globular clusters out there where people think maybe there's 775 00:38:14,840 --> 00:38:17,640 Speaker 1: a black hole there based on the measurements of velocities 776 00:38:17,640 --> 00:38:19,719 Speaker 1: of the stars, but none of them really hold a 777 00:38:19,800 --> 00:38:22,239 Speaker 1: to scrutiny. Like somebody announces, wow, look we found an 778 00:38:22,239 --> 00:38:25,120 Speaker 1: intermediate mass black hole, and then another group looks at 779 00:38:25,160 --> 00:38:27,200 Speaker 1: the same measurements and they say, no, we can explain 780 00:38:27,280 --> 00:38:29,640 Speaker 1: this without a black hole, So it doesn't really hold up. 781 00:38:29,800 --> 00:38:31,920 Speaker 1: You see, it's tricky. It's tricky because you have to 782 00:38:32,000 --> 00:38:34,879 Speaker 1: kind of like see the footprint of the black hole, 783 00:38:35,320 --> 00:38:38,040 Speaker 1: and it's not easy to do. And another technique is 784 00:38:38,120 --> 00:38:41,000 Speaker 1: to look not for the motion of stars, but for 785 00:38:41,080 --> 00:38:44,320 Speaker 1: the radiation from the accretion disc Right, we know that 786 00:38:44,440 --> 00:38:46,560 Speaker 1: black holes are not on their own, and especially the 787 00:38:46,680 --> 00:38:49,400 Speaker 1: massive ones in the centers of galaxies are surrounded by 788 00:38:49,520 --> 00:38:52,320 Speaker 1: gas and dust that's emitting a lot of radiation, so 789 00:38:52,400 --> 00:38:55,799 Speaker 1: these are called quasars. And we think that intermediate mass 790 00:38:55,840 --> 00:38:58,880 Speaker 1: black holes should also have intermediate mass accretion disks and 791 00:38:59,000 --> 00:39:02,480 Speaker 1: be intermediate as quasars, So we're looking for these as well. 792 00:39:02,719 --> 00:39:08,319 Speaker 1: Really we've only seen like supermassive quasars or stellar size quasars. Yes, 793 00:39:08,400 --> 00:39:12,359 Speaker 1: we've only seen supermassive quasars. Stellar mass black holes don't 794 00:39:12,360 --> 00:39:14,160 Speaker 1: tend to have quasars because they don't have the mass 795 00:39:14,520 --> 00:39:17,320 Speaker 1: to get their creation disk like up to that energy, 796 00:39:17,680 --> 00:39:20,160 Speaker 1: so they tend to only be from the centers of galaxies. 797 00:39:20,719 --> 00:39:22,880 Speaker 1: And the problem here is that we're looking for like 798 00:39:23,200 --> 00:39:26,320 Speaker 1: really old galaxies before they got really really big, so 799 00:39:26,440 --> 00:39:29,680 Speaker 1: like intermediate size galaxies, and these tend to be pretty 800 00:39:29,719 --> 00:39:33,080 Speaker 1: far away. And if you're looking for the black hole, 801 00:39:33,160 --> 00:39:35,239 Speaker 1: because it's a quasar, it tends to like drown out 802 00:39:35,320 --> 00:39:37,479 Speaker 1: the rest of the galaxy, so you can't like really 803 00:39:37,560 --> 00:39:40,000 Speaker 1: see what's going on in the galaxy. So we have 804 00:39:40,200 --> 00:39:43,680 Speaker 1: these quasars we've identified as maybe candidates for intermediate mass 805 00:39:43,719 --> 00:39:45,880 Speaker 1: black holes, but they're so far away we can't like 806 00:39:45,960 --> 00:39:48,399 Speaker 1: see the stars and really identify whether there's a black 807 00:39:48,480 --> 00:39:50,440 Speaker 1: hole there. Oh, I see, because there could just be 808 00:39:50,520 --> 00:39:53,160 Speaker 1: like a bunch of stars, yeah, clustered together. So but 809 00:39:53,239 --> 00:39:55,120 Speaker 1: that's one thing people are doing. But I think the 810 00:39:55,239 --> 00:39:58,959 Speaker 1: most exciting is this brand new way we have looking 811 00:39:59,040 --> 00:40:01,480 Speaker 1: at the universe first seeing things that's not based on 812 00:40:01,640 --> 00:40:05,200 Speaker 1: light but based on gravitational waves, right, like the ripples 813 00:40:05,320 --> 00:40:08,400 Speaker 1: and off space. Yes, out there in the universe, the 814 00:40:08,520 --> 00:40:12,520 Speaker 1: ripples in space itself, because when anything accelerates in the universe, 815 00:40:12,880 --> 00:40:15,840 Speaker 1: it creates a change in the gravitational field, and that 816 00:40:16,040 --> 00:40:19,399 Speaker 1: change ripples through space. And if the thing is really 817 00:40:19,480 --> 00:40:22,240 Speaker 1: really big, really really massive, and moving really really fast, 818 00:40:22,480 --> 00:40:26,040 Speaker 1: then you can actually measure these gravitational waves billions and 819 00:40:26,160 --> 00:40:28,880 Speaker 1: billions of light years away, and we have and the 820 00:40:29,080 --> 00:40:32,120 Speaker 1: things that have generated the gravitational waves that we've been 821 00:40:32,120 --> 00:40:34,960 Speaker 1: able to see here on Earth in observatories like Lego 822 00:40:35,280 --> 00:40:38,600 Speaker 1: are the mergers. For example, of two black holes falling 823 00:40:38,719 --> 00:40:41,279 Speaker 1: into each other, they accelerate around each other in this 824 00:40:41,520 --> 00:40:44,680 Speaker 1: crazy death spiral, emitting a huge amount of energy as 825 00:40:44,760 --> 00:40:47,920 Speaker 1: gravitational waves, and that we can use to figure out 826 00:40:48,160 --> 00:40:50,520 Speaker 1: how massive were the two black holes that fell in 827 00:40:50,760 --> 00:40:53,479 Speaker 1: and how massive is the resulting black hole, right because 828 00:40:53,719 --> 00:40:56,600 Speaker 1: you're seeing like the actual ripples and gravity from these 829 00:40:56,640 --> 00:40:59,879 Speaker 1: black holes, So just the ripple itself kind of tell 830 00:41:00,600 --> 00:41:02,640 Speaker 1: how big the things are that are crashing into each 831 00:41:02,640 --> 00:41:05,760 Speaker 1: other it's a very very detailed fingerprint because the ripples 832 00:41:05,800 --> 00:41:07,440 Speaker 1: tell you how fast things were going, and from that 833 00:41:07,560 --> 00:41:09,719 Speaker 1: you can back out things like how massive they must 834 00:41:09,800 --> 00:41:12,399 Speaker 1: have been, how strong was the gravity, and so yeah, 835 00:41:12,440 --> 00:41:15,120 Speaker 1: you can figure out how massive the individual black holes 836 00:41:15,120 --> 00:41:17,600 Speaker 1: were before they collapsed, and the mass of the final 837 00:41:17,640 --> 00:41:19,799 Speaker 1: black hole, which is not just the two black holes 838 00:41:19,800 --> 00:41:22,520 Speaker 1: added together. Some of the energy from the original two 839 00:41:22,520 --> 00:41:26,320 Speaker 1: black holes get lost in gravitational radiation, these gravitational waves, 840 00:41:26,440 --> 00:41:28,080 Speaker 1: and so the idea is that you know, we can 841 00:41:28,800 --> 00:41:32,080 Speaker 1: listen to when these black holes crashing into each other, 842 00:41:32,520 --> 00:41:34,560 Speaker 1: and so you're saying, like, maybe one day we'll see 843 00:41:34,840 --> 00:41:38,640 Speaker 1: or hear are the tag two intermediate black holes crashing 844 00:41:38,719 --> 00:41:40,680 Speaker 1: into each other, and then we'll be able to say, hey, 845 00:41:40,800 --> 00:41:44,040 Speaker 1: there's an intermediate one. Yes, absolutely, that's a possibility, because 846 00:41:44,120 --> 00:41:46,040 Speaker 1: we can use this as a way to weigh black 847 00:41:46,080 --> 00:41:49,360 Speaker 1: holes and we cannot otherwise directly see right, because remember, 848 00:41:49,360 --> 00:41:52,719 Speaker 1: gravitational waves can pass through anything. No amount of gas 849 00:41:52,920 --> 00:41:55,279 Speaker 1: or dust or radiation or whatever can stop them. So 850 00:41:55,360 --> 00:41:58,640 Speaker 1: it's just another very powerful orthogonal way of looking at 851 00:41:58,680 --> 00:42:01,440 Speaker 1: the universe, so we can get glimpses. Also, there's another 852 00:42:01,560 --> 00:42:04,720 Speaker 1: angle there, which is maybe we can see two really 853 00:42:04,880 --> 00:42:08,800 Speaker 1: really big stellar mass black holes merge. Like what happens 854 00:42:08,800 --> 00:42:11,120 Speaker 1: when an eighties solar mass black hole and a seventies 855 00:42:11,120 --> 00:42:15,000 Speaker 1: solar mass black hole get together, Well, they must form 856 00:42:15,320 --> 00:42:17,919 Speaker 1: a black hole that's heavier, right, that maybe even over 857 00:42:18,040 --> 00:42:21,600 Speaker 1: that threshold into the intermediate mass range. Here, it's an 858 00:42:21,840 --> 00:42:28,200 Speaker 1: X rated event there that Yeah, and this has actually happened. 859 00:42:28,280 --> 00:42:31,440 Speaker 1: And in two thousand nineteen they did see a merger 860 00:42:31,600 --> 00:42:34,200 Speaker 1: that resulted in a black hole that weighed a hundred 861 00:42:34,239 --> 00:42:37,160 Speaker 1: and forty two solar masses. And so this is really cool. 862 00:42:37,239 --> 00:42:39,279 Speaker 1: You can look this up on Lego. They call this 863 00:42:39,440 --> 00:42:42,120 Speaker 1: the black hole graveyard, and they showed like the masses 864 00:42:42,200 --> 00:42:44,240 Speaker 1: of the black holes that formed the new black holes. 865 00:42:44,360 --> 00:42:46,319 Speaker 1: And so we're now seeing more and more of these things, 866 00:42:46,360 --> 00:42:48,319 Speaker 1: and they're sort of pushing up that limit. Like it's 867 00:42:48,360 --> 00:42:50,440 Speaker 1: true that you can't make a black hole from a 868 00:42:50,520 --> 00:42:54,120 Speaker 1: single star that's bigger than eighty but as you said earlier, 869 00:42:54,160 --> 00:42:56,080 Speaker 1: as you start to combine these, they can creep up 870 00:42:56,080 --> 00:42:59,560 Speaker 1: a little bit and get over that hundred stellar mass threshold. Right, 871 00:42:59,800 --> 00:43:01,520 Speaker 1: And we've seen this, right, you're saying, you can go 872 00:43:01,600 --> 00:43:03,680 Speaker 1: online and look at the data of a hundred and 873 00:43:03,760 --> 00:43:07,879 Speaker 1: forty two solar mass black hole basically being born. Yes, 874 00:43:08,120 --> 00:43:10,080 Speaker 1: you can see it. It happened billions of years ago, 875 00:43:10,160 --> 00:43:12,560 Speaker 1: but just recently seeing the evidence here on Earth, so 876 00:43:12,640 --> 00:43:15,160 Speaker 1: that's exciting. It sort of cracks that number. It doesn't 877 00:43:15,200 --> 00:43:17,560 Speaker 1: really answer the mystery, right because it doesn't explain why 878 00:43:17,640 --> 00:43:19,840 Speaker 1: we don't see them. At A thousand and five thousand 879 00:43:19,920 --> 00:43:23,320 Speaker 1: and ten thousand, it's like just over the threshold of 880 00:43:23,400 --> 00:43:26,719 Speaker 1: what you might consider intermediate mass black hole. But we're 881 00:43:26,760 --> 00:43:32,040 Speaker 1: planning to build future crazy gravitational observatories that might be 882 00:43:32,120 --> 00:43:34,440 Speaker 1: able to see even bigger ones from further away. I 883 00:43:34,440 --> 00:43:36,840 Speaker 1: don't know if you've heard about the Lisa experiment. No, 884 00:43:37,520 --> 00:43:40,120 Speaker 1: what is it. The Lisa experiment is a version of Ligo. 885 00:43:40,560 --> 00:43:44,120 Speaker 1: This experiment we have mirrors dangling underground in Louisiana and 886 00:43:44,200 --> 00:43:47,320 Speaker 1: in Washington and in Italy to observe the ripples of space. 887 00:43:47,640 --> 00:43:50,160 Speaker 1: This is a version of it, but using three satellites 888 00:43:50,320 --> 00:43:54,600 Speaker 1: in space placed like really really far apart, but precisely 889 00:43:54,680 --> 00:43:58,400 Speaker 1: aligned relative to each other. Wow, that's pretty cool in space. 890 00:43:58,680 --> 00:44:01,360 Speaker 1: In space, I know, it's names bonkers, right that you 891 00:44:01,440 --> 00:44:04,440 Speaker 1: could have like two satellites and have them maintain an 892 00:44:04,480 --> 00:44:07,080 Speaker 1: exact distance relative to each other. It's going to be 893 00:44:07,239 --> 00:44:11,040 Speaker 1: very complicated and very expensive. But if they build it 894 00:44:11,440 --> 00:44:15,239 Speaker 1: this facility, Lisa will be very powerful at seeing gravitational 895 00:44:15,320 --> 00:44:18,200 Speaker 1: waves and you could detect them from intermediate mass black 896 00:44:18,239 --> 00:44:22,160 Speaker 1: hole murders Lisa in space. It sounds like a song. 897 00:44:23,320 --> 00:44:25,400 Speaker 1: He ripped that off from the Beatles, Lisa and the 898 00:44:25,440 --> 00:44:29,680 Speaker 1: Sky black Holes. All right, Well, I think you convince me, Daniel. 899 00:44:29,719 --> 00:44:32,000 Speaker 1: I think the middle children are pretty cool or they 900 00:44:32,040 --> 00:44:35,239 Speaker 1: don't exist one of the two. Sometimes I feel that way. 901 00:44:35,440 --> 00:44:39,000 Speaker 1: They're definitely lurking, They're big. Middle children are big lurkers. 902 00:44:39,080 --> 00:44:41,800 Speaker 1: For sure. We are psychological lurkers. Yes, So it's a 903 00:44:41,800 --> 00:44:44,200 Speaker 1: really fun question like why don't we see these things? 904 00:44:44,719 --> 00:44:47,279 Speaker 1: How did the supermassive black holes get so big without 905 00:44:47,320 --> 00:44:49,400 Speaker 1: going through this stage? Or maybe we don't see them 906 00:44:49,480 --> 00:44:51,480 Speaker 1: just because we don't have the telescopes yet, And in 907 00:44:51,560 --> 00:44:53,520 Speaker 1: twenty or thirty years we'll see a bunch of them 908 00:44:53,719 --> 00:44:55,560 Speaker 1: and they'll answer a lot of our questions about how 909 00:44:55,680 --> 00:44:58,680 Speaker 1: black holes get made because they are, I guess, in general, 910 00:44:58,800 --> 00:45:01,360 Speaker 1: just a cool family. You know, the youngest siblings and 911 00:45:01,440 --> 00:45:03,440 Speaker 1: the oldest siblings. They're all pretty cool in their own 912 00:45:03,480 --> 00:45:07,360 Speaker 1: way and pretty impactful in the universe. Right, everybody contribute 913 00:45:07,360 --> 00:45:09,719 Speaker 1: to the family. We love every part of it. All right, 914 00:45:09,760 --> 00:45:12,040 Speaker 1: I guess we'll leave that question dankling. What happened to 915 00:45:12,120 --> 00:45:15,960 Speaker 1: the intermediate black holes? Nobody knows. It's a black hole 916 00:45:16,040 --> 00:45:18,839 Speaker 1: in itself of information, but we'll figure it out. Stay 917 00:45:18,920 --> 00:45:21,480 Speaker 1: tuned for more updates from science. You might have to 918 00:45:21,520 --> 00:45:25,920 Speaker 1: wait another three episodes until Daniel figures it out his therapist, 919 00:45:26,040 --> 00:45:28,960 Speaker 1: but we'll get there, okay, all right. We hope you 920 00:45:29,040 --> 00:45:31,600 Speaker 1: enjoyed that. Thanks for joining us, See you next time. 921 00:45:39,560 --> 00:45:42,400 Speaker 1: Thanks for listening, and remember that Daniel and Jorge explained. 922 00:45:42,400 --> 00:45:45,279 Speaker 1: The Universe is a production of I Heart Radio. For 923 00:45:45,440 --> 00:45:48,359 Speaker 1: more podcast from my Heart Radio, visit the i heart 924 00:45:48,440 --> 00:45:52,000 Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your 925 00:45:52,080 --> 00:45:52,800 Speaker 1: favorite shows.