1 00:00:07,160 --> 00:00:09,200 Speaker 1: So I was outside the other night with my son 2 00:00:09,280 --> 00:00:11,119 Speaker 1: looking up at the sky, and we were having a 3 00:00:11,119 --> 00:00:12,880 Speaker 1: great time, and he turned to me and he asked 4 00:00:12,920 --> 00:00:16,760 Speaker 1: me a question. He said, Hey, Dad, why are there stars? 5 00:00:17,480 --> 00:00:22,440 Speaker 1: You mean like movie stars? No, No, why astronomical stars? 6 00:00:22,440 --> 00:00:24,599 Speaker 1: He wanted to know. Wow, what did you say? Well? 7 00:00:24,640 --> 00:00:27,320 Speaker 1: I thought he was asking me, like, why do stars exist? 8 00:00:27,440 --> 00:00:29,120 Speaker 1: You know, why do we have bright stars in the sky. 9 00:00:29,240 --> 00:00:31,760 Speaker 1: So of course I give him a long physics explanation 10 00:00:31,840 --> 00:00:33,720 Speaker 1: for you know, how funion works and all this kind 11 00:00:33,720 --> 00:00:35,559 Speaker 1: of stuff. I wonder what it's like to have your 12 00:00:35,640 --> 00:00:41,000 Speaker 1: dad be a physics professor. It's awesome. It's awesome. I 13 00:00:41,320 --> 00:00:42,879 Speaker 1: wonder how many times he's just like dad. I just 14 00:00:42,880 --> 00:00:48,800 Speaker 1: wanted a one sentence answer. I once heard him explaining 15 00:00:48,800 --> 00:00:52,080 Speaker 1: to his friends about black holes, and I thought, Hey, 16 00:00:52,400 --> 00:00:57,440 Speaker 1: that dude is cool because of me. I think cool 17 00:00:57,480 --> 00:01:01,120 Speaker 1: as might not be the appropriate adjective here. But what's 18 00:01:01,120 --> 00:01:04,520 Speaker 1: the What's he satisfied with your explanation? No? Not at all. 19 00:01:04,600 --> 00:01:07,119 Speaker 1: In fact, it turns out I totally misunderstood his question. 20 00:01:07,640 --> 00:01:09,960 Speaker 1: When he asked why are their stars? He didn't mean 21 00:01:10,040 --> 00:01:12,520 Speaker 1: like why does the star burn? He meant like, why 22 00:01:12,520 --> 00:01:15,039 Speaker 1: are their stars? Plural, like why don't we just have 23 00:01:15,440 --> 00:01:18,440 Speaker 1: one star? Right? Or like why isn't everything just spread 24 00:01:18,440 --> 00:01:21,040 Speaker 1: out smoothly in the universe? Why does things clump together 25 00:01:21,080 --> 00:01:23,720 Speaker 1: to make planets and stars and all that stuff? WHOA, 26 00:01:24,640 --> 00:01:27,640 Speaker 1: That is a good question. Yeah, it's a great question. 27 00:01:27,640 --> 00:01:29,560 Speaker 1: It's a kind of question kids ask, right, the kind 28 00:01:29,560 --> 00:01:32,160 Speaker 1: of question you don't necessarily think to ask. It's such 29 00:01:32,200 --> 00:01:34,840 Speaker 1: a basic, simple question. That's a question I have. And 30 00:01:34,840 --> 00:01:55,680 Speaker 1: I'm I'm definitely not five years old. Ye I am 31 00:01:55,680 --> 00:01:59,120 Speaker 1: Morhan and I'm Daniel, and welcome to our podcast, Daniel 32 00:01:59,160 --> 00:02:01,800 Speaker 1: and Jorgey Wayne the Universe, in which we try to 33 00:02:01,840 --> 00:02:05,000 Speaker 1: take everything or anything in the universe, even the obvious 34 00:02:05,040 --> 00:02:07,520 Speaker 1: stuff like stars, and explain it to you. Why is 35 00:02:07,560 --> 00:02:09,480 Speaker 1: it there? How does it work? Do I have to 36 00:02:09,480 --> 00:02:12,160 Speaker 1: worry about it? Can I buy one online? We try 37 00:02:12,200 --> 00:02:15,600 Speaker 1: to answer the smooth questions and also the lumpy questions. 38 00:02:16,840 --> 00:02:18,320 Speaker 1: And today is going to be a bit of a 39 00:02:18,400 --> 00:02:21,440 Speaker 1: lumpy episode. Today on the program, we're asking the question 40 00:02:26,680 --> 00:02:30,240 Speaker 1: why are there stars? The universe has a really strange 41 00:02:30,360 --> 00:02:34,480 Speaker 1: kind of shape. I mean, it's huge, but it's mostly empty, right, 42 00:02:34,560 --> 00:02:38,679 Speaker 1: Like there's vast distances between stars and even vaster ones 43 00:02:38,720 --> 00:02:42,079 Speaker 1: between galaxies. But then you have these hot little points, right, 44 00:02:42,200 --> 00:02:45,200 Speaker 1: all this matter concentrated in these little dots. It's a 45 00:02:45,360 --> 00:02:48,960 Speaker 1: really weird arrangement. Why is it concentrating these little pin points? 46 00:02:49,400 --> 00:02:53,000 Speaker 1: Why isn't more diffuse or why don't all those pin 47 00:02:53,040 --> 00:02:55,640 Speaker 1: points just clumped together? Yeah? Why don't we have just 48 00:02:55,760 --> 00:02:59,960 Speaker 1: one mega star or like a big pudding of delute 49 00:03:00,080 --> 00:03:03,120 Speaker 1: gas everywhere? Right? Why is the universe the way it 50 00:03:03,240 --> 00:03:05,280 Speaker 1: is and not any of those other ways? It could 51 00:03:05,280 --> 00:03:08,519 Speaker 1: have been those ways in some alternate multiverse. It probably 52 00:03:08,560 --> 00:03:10,720 Speaker 1: is those ways, but in those multiverses they don't have 53 00:03:10,760 --> 00:03:14,079 Speaker 1: awesome podcasts to ask this question. Yeah. Yeah, because you 54 00:03:14,080 --> 00:03:16,440 Speaker 1: look at the night sky and it's beautiful, right, I 55 00:03:16,440 --> 00:03:19,839 Speaker 1: mean it's it's like this black void with little white pinpoints. 56 00:03:20,040 --> 00:03:23,320 Speaker 1: But you gotta wonder why does it look that way? Okay, 57 00:03:23,320 --> 00:03:25,360 Speaker 1: so I have to take a digression here an artistic 58 00:03:25,440 --> 00:03:28,800 Speaker 1: question for you or here, which is why do you 59 00:03:28,880 --> 00:03:31,960 Speaker 1: think we find the night sky beautiful? I mean, I agree, 60 00:03:32,000 --> 00:03:34,200 Speaker 1: it's gorgeous. This is the best view in the universe, right, 61 00:03:34,560 --> 00:03:36,680 Speaker 1: But is it necessary do we find it beautiful to 62 00:03:36,760 --> 00:03:39,520 Speaker 1: be evolved to find it beautiful? Is it just chance? Like? 63 00:03:39,560 --> 00:03:41,080 Speaker 1: Could we have evolved in a way. We look up 64 00:03:41,080 --> 00:03:45,680 Speaker 1: at the night stine, We're like, yuck, that's gross. M h. Well, 65 00:03:45,720 --> 00:03:50,160 Speaker 1: I think we have a innate appreciation for sparkly things, right, 66 00:03:50,200 --> 00:03:55,200 Speaker 1: we like we'll all pyromaniacs. Yeah, no, I mean evolved 67 00:03:55,200 --> 00:03:59,440 Speaker 1: evolved from liking water maybe or being attracted to water 68 00:03:59,600 --> 00:04:02,920 Speaker 1: or spark the water. I don't know, sparkling water. They 69 00:04:02,920 --> 00:04:07,520 Speaker 1: had ivan then caved mondays right, Yeah, I think people 70 00:04:07,600 --> 00:04:09,600 Speaker 1: used to carbonate their own water back in cave men days. 71 00:04:09,600 --> 00:04:12,080 Speaker 1: I'm pretty sure that we should have asked that question 72 00:04:12,160 --> 00:04:13,920 Speaker 1: Ryan North when we had him on the podcast. When 73 00:04:13,960 --> 00:04:18,160 Speaker 1: did they invent sparkling water? The greatest invention all time? 74 00:04:18,480 --> 00:04:23,920 Speaker 1: Sparkling water. That's a great question is why are there 75 00:04:24,040 --> 00:04:29,480 Speaker 1: stars and planets as opposed to just having a monotonous, 76 00:04:30,640 --> 00:04:39,120 Speaker 1: monogamous no homogeneous, monochronous, monochromatic Yeah, I mean like a 77 00:04:39,160 --> 00:04:41,520 Speaker 1: plane universe. I guess why do we have stars and 78 00:04:41,520 --> 00:04:46,640 Speaker 1: planets and objects and spark the objects and things rather 79 00:04:46,760 --> 00:04:50,800 Speaker 1: than we're just living in a giant gas cloud. That's right. Yeah, 80 00:04:50,880 --> 00:04:53,279 Speaker 1: So that's the question we're gonna try to tackle today, 81 00:04:53,680 --> 00:04:56,080 Speaker 1: give you a solid answer for it. And so as 82 00:04:56,200 --> 00:04:59,440 Speaker 1: usual before we answer the question we I went out 83 00:04:59,480 --> 00:05:02,320 Speaker 1: and I asked bunch of unsuspecting you see, Irvine students, 84 00:05:02,400 --> 00:05:04,919 Speaker 1: off the top of their head. I asked them that question. 85 00:05:05,120 --> 00:05:07,679 Speaker 1: So think about it at home or wherever you're listening. 86 00:05:07,839 --> 00:05:10,280 Speaker 1: Why do you think there are stars and planets and 87 00:05:10,360 --> 00:05:14,520 Speaker 1: not just a smooth universe? Here's what people had to say. 88 00:05:14,680 --> 00:05:17,120 Speaker 1: Why is the universe so lumpy like? Why doesn't matter 89 00:05:17,200 --> 00:05:19,760 Speaker 1: just spread out totally smoothly and evenly through the universe. 90 00:05:20,279 --> 00:05:23,599 Speaker 1: I want to say gravity, because there's like a certain 91 00:05:23,680 --> 00:05:28,120 Speaker 1: kind of gravity putting things in place. And I have 92 00:05:28,320 --> 00:05:32,760 Speaker 1: no idea. Okay, gravity, it's a result of the big bank. 93 00:05:32,960 --> 00:05:36,599 Speaker 1: You had matter and antimatter, and they made clumps and 94 00:05:36,720 --> 00:05:40,640 Speaker 1: they kept expanding, and that's just how it occurred. At 95 00:05:40,720 --> 00:05:45,600 Speaker 1: least that's the model that I've heard. There were at 96 00:05:45,680 --> 00:05:48,719 Speaker 1: some point areas where there was a slight greater density, 97 00:05:49,200 --> 00:05:52,120 Speaker 1: and you know, in the matter in the universevity works, 98 00:05:52,120 --> 00:05:55,320 Speaker 1: a greater density will kind of collapse in the greater 99 00:05:55,320 --> 00:05:57,040 Speaker 1: and greater and greater density to you have a galaxy, 100 00:05:57,040 --> 00:06:01,400 Speaker 1: your plans or whatever the ions. Okay, all right, so 101 00:06:01,480 --> 00:06:03,760 Speaker 1: that's pretty interesting. I feel like you should maybe stop 102 00:06:03,800 --> 00:06:07,120 Speaker 1: advertising that they're U s Irvine students because I don't 103 00:06:07,120 --> 00:06:10,200 Speaker 1: know if you're helping the marketing there. I think it's 104 00:06:10,240 --> 00:06:13,040 Speaker 1: wonderful all these U see Irvine students are willing to 105 00:06:13,080 --> 00:06:16,359 Speaker 1: stop and think about a random question from a randy, 106 00:06:16,760 --> 00:06:21,040 Speaker 1: random scruffy looking dude and think about the universe. Likecent 107 00:06:21,120 --> 00:06:23,800 Speaker 1: of people answer these questions. To me, they get full 108 00:06:23,800 --> 00:06:26,280 Speaker 1: credit even just for trying, for thinking about it, for 109 00:06:26,440 --> 00:06:29,480 Speaker 1: engaging right. To me, that's wonderful. When we first started 110 00:06:29,480 --> 00:06:31,200 Speaker 1: this project, I was sure I was going to get 111 00:06:31,240 --> 00:06:34,000 Speaker 1: one percent answers. So the fact that they don't know 112 00:06:34,320 --> 00:06:36,520 Speaker 1: not a big deal. The fact that they try to answer, 113 00:06:36,800 --> 00:06:38,520 Speaker 1: that's wonderful. I think you should try it down the 114 00:06:38,520 --> 00:06:40,400 Speaker 1: streets of New York next and see what kind of 115 00:06:40,400 --> 00:06:43,080 Speaker 1: reaction you get get out of here. Yeah, well, as 116 00:06:43,080 --> 00:06:45,160 Speaker 1: you were suggesting, maybe I should go up to cal 117 00:06:45,200 --> 00:06:48,400 Speaker 1: Tech and see see if they get them more precise answers. 118 00:06:48,800 --> 00:06:51,919 Speaker 1: But everyone seems to say gravity as the answer to 119 00:06:51,960 --> 00:06:54,960 Speaker 1: the question. Yeah, everybody says gravity, And I think that 120 00:06:55,120 --> 00:06:59,600 Speaker 1: comes from everybody's feeling correctly that gravity plays a big role, right. 121 00:06:59,640 --> 00:07:02,280 Speaker 1: Gravity is the thing that made these structures. Gravity is 122 00:07:02,279 --> 00:07:06,200 Speaker 1: which responsible for holding a start together. Gravity controls the 123 00:07:06,200 --> 00:07:09,159 Speaker 1: shape of the galaxy. Gravity certainly plays a big role, 124 00:07:09,960 --> 00:07:13,240 Speaker 1: but I guess the twist is that it's not the 125 00:07:13,280 --> 00:07:15,760 Speaker 1: only thing you need to make stars. Right. Gravity only 126 00:07:15,760 --> 00:07:19,200 Speaker 1: clumps links together if you if you already have small 127 00:07:19,240 --> 00:07:22,200 Speaker 1: clumps to begin with, right, that's right, Gravity is not 128 00:07:22,280 --> 00:07:25,440 Speaker 1: the complete answer. If you had a universe that was 129 00:07:25,600 --> 00:07:30,200 Speaker 1: totally smooth, right, completely smooth, then gravity couldn't do anything 130 00:07:30,920 --> 00:07:33,520 Speaker 1: because each particle in the universe would be pulled both 131 00:07:33,640 --> 00:07:36,480 Speaker 1: left and right with equal force because it would be 132 00:07:36,560 --> 00:07:39,240 Speaker 1: equal amounts of stuff on both sides of it, And 133 00:07:39,280 --> 00:07:42,119 Speaker 1: so every object would be sort of like pinned down 134 00:07:42,160 --> 00:07:45,800 Speaker 1: by gravity. But it couldn't form any structures, right, So 135 00:07:45,880 --> 00:07:49,840 Speaker 1: gravity can't make lumps. It can only exaggerate lumps. Once 136 00:07:49,880 --> 00:07:52,520 Speaker 1: you've gotten a little bit started, we paint that picture 137 00:07:52,560 --> 00:07:54,360 Speaker 1: a little bit more for me. So let's imagine a 138 00:07:54,440 --> 00:07:59,120 Speaker 1: perfectly smooth universe, meaning that all the particles in the 139 00:07:59,240 --> 00:08:02,360 Speaker 1: universe are kind of at the same distance from each 140 00:08:02,360 --> 00:08:06,320 Speaker 1: other as every other particle in the universe exactly. So imagine, 141 00:08:06,680 --> 00:08:08,720 Speaker 1: you know, every particle is on a grid, right, and 142 00:08:09,120 --> 00:08:11,800 Speaker 1: they have one particle every centimeter or something. Right, So 143 00:08:12,200 --> 00:08:15,680 Speaker 1: take a perfectly exact grid. Everyone. Every particle is one 144 00:08:15,720 --> 00:08:18,960 Speaker 1: centimeter apart from the next particle exactly. And if you're 145 00:08:18,960 --> 00:08:22,080 Speaker 1: thinking this is strange and artificial, it's actually very simple, right, 146 00:08:22,080 --> 00:08:25,680 Speaker 1: And it's very natural. The opposite idea that there's one 147 00:08:25,680 --> 00:08:28,640 Speaker 1: place where there's particles are closer together, or they're denser 148 00:08:28,760 --> 00:08:32,280 Speaker 1: and they're denser, or something that's strange, that's unusual, that 149 00:08:32,320 --> 00:08:34,920 Speaker 1: would be like, well, why they're not here. So having 150 00:08:34,960 --> 00:08:38,360 Speaker 1: a perfectly smooth, symmetric universe as a as a starting 151 00:08:38,400 --> 00:08:41,680 Speaker 1: point actually makes the most sense. It's the most natural concept, 152 00:08:42,320 --> 00:08:46,080 Speaker 1: like a perfect jelly or like a perfect crystal exactly, 153 00:08:46,320 --> 00:08:49,000 Speaker 1: like a perfectly smooth chocolate pudding with new lumps in it. Right. 154 00:08:49,880 --> 00:08:53,000 Speaker 1: So if and and if the universe is infinite, you're 155 00:08:53,000 --> 00:08:58,440 Speaker 1: saying that cloud of perfectly ordered particles would not clump 156 00:08:58,480 --> 00:09:01,760 Speaker 1: together exactly. So take one random particle, right, And it 157 00:09:01,760 --> 00:09:03,760 Speaker 1: doesn't matter which one you choose, because we set this 158 00:09:03,840 --> 00:09:06,280 Speaker 1: up so that all the particles are exactly the same. 159 00:09:06,600 --> 00:09:09,760 Speaker 1: So pick one random particle. Now, that particle is going 160 00:09:09,800 --> 00:09:12,199 Speaker 1: to get pulled on by all the other particles in 161 00:09:12,240 --> 00:09:14,559 Speaker 1: the universe due to gravity and other forces. But let's 162 00:09:14,600 --> 00:09:17,959 Speaker 1: just think about gravity right now. Now, Um, there's an 163 00:09:18,000 --> 00:09:20,240 Speaker 1: infinite number of particles pulling it to the left, and 164 00:09:20,280 --> 00:09:22,600 Speaker 1: an infinite number of particles pulling it to the right, 165 00:09:22,840 --> 00:09:25,280 Speaker 1: and up and down to right exactly, and in any 166 00:09:25,400 --> 00:09:28,679 Speaker 1: any way you slice it, you get the same answer. Right. Um, 167 00:09:28,760 --> 00:09:31,520 Speaker 1: you divide the universe into two halves around this particle, 168 00:09:31,840 --> 00:09:33,560 Speaker 1: and one half of the universe is pulling it one way, 169 00:09:33,600 --> 00:09:35,080 Speaker 1: the other half is pulling it the other way. It 170 00:09:35,160 --> 00:09:39,400 Speaker 1: exactly balances out. It cancels perfectly. Right. It's like if 171 00:09:39,440 --> 00:09:41,160 Speaker 1: you have two kids and each one is pulling on 172 00:09:41,160 --> 00:09:44,440 Speaker 1: one arm, You're not going anywhere. Right. Does that happen 173 00:09:44,480 --> 00:09:47,920 Speaker 1: to you often? That's a random hypothetical I just invented. 174 00:09:47,960 --> 00:09:49,520 Speaker 1: It's not that I have two kids who often have 175 00:09:49,640 --> 00:09:53,440 Speaker 1: totally different ideas about what we should do or um, 176 00:09:53,480 --> 00:09:55,280 Speaker 1: where they want to go or where they want to eat. 177 00:09:55,880 --> 00:09:59,360 Speaker 1: That's right, um. And so in this scenario, every particle 178 00:09:59,600 --> 00:10:03,760 Speaker 1: is an equilibrium. Right. There's no way to begin lumpiness 179 00:10:03,760 --> 00:10:07,240 Speaker 1: because everything is being tugged equally left and right or 180 00:10:07,400 --> 00:10:10,160 Speaker 1: up and down, or you know, back and forth. So 181 00:10:10,200 --> 00:10:13,320 Speaker 1: you would the universe would just sit there, It would 182 00:10:13,320 --> 00:10:16,760 Speaker 1: just stay static. It would it wouldn't wouldn't move right, like, 183 00:10:17,200 --> 00:10:19,520 Speaker 1: we would just stay there forever, because every particle would 184 00:10:19,520 --> 00:10:22,640 Speaker 1: just be perfectly bounds where it is. Exactly. It's like 185 00:10:22,679 --> 00:10:25,240 Speaker 1: if you put a ball in the bottom of a bowl, right, 186 00:10:25,240 --> 00:10:28,120 Speaker 1: it's just gonna sit there. It's not gonna go anywhere, right, 187 00:10:28,160 --> 00:10:30,600 Speaker 1: And that's exactly the situation of each of those particles. 188 00:10:30,600 --> 00:10:33,240 Speaker 1: They're sitting in the bottom of a bowl. That bowl 189 00:10:33,320 --> 00:10:35,920 Speaker 1: is the gravitational well made by all the other particles 190 00:10:35,920 --> 00:10:38,960 Speaker 1: in the universe. And so if the universe is infinite, 191 00:10:39,080 --> 00:10:42,400 Speaker 1: then you can apply the same argument to every particle, right. 192 00:10:42,480 --> 00:10:45,679 Speaker 1: And so if you start out with an infinite, smooth universe, 193 00:10:46,240 --> 00:10:50,000 Speaker 1: then you can't get any structure. You can't start to 194 00:10:50,000 --> 00:10:52,640 Speaker 1: build anything. Hold on, you said that if that's only 195 00:10:52,679 --> 00:10:54,920 Speaker 1: if the universe is infinite, But what happens if we 196 00:10:54,960 --> 00:10:58,319 Speaker 1: have this perfect jelly and the universe is finite, meaning 197 00:10:58,880 --> 00:11:01,960 Speaker 1: that at some point ends. Yeah, well, then this argument 198 00:11:01,960 --> 00:11:05,679 Speaker 1: doesn't apply because there's some point um Because then this 199 00:11:05,800 --> 00:11:08,800 Speaker 1: argument only applies to the very center of the universe. Right. Then, 200 00:11:08,840 --> 00:11:11,760 Speaker 1: if the universe is finite, that means that it has 201 00:11:11,800 --> 00:11:14,400 Speaker 1: a center, right, that there's someplace where there's an equal 202 00:11:14,440 --> 00:11:16,040 Speaker 1: amount of stuff to the left and to the right 203 00:11:16,080 --> 00:11:19,079 Speaker 1: and up and down right, and this argument would only 204 00:11:19,080 --> 00:11:21,680 Speaker 1: apply right there, or if you go to the edge 205 00:11:21,720 --> 00:11:24,280 Speaker 1: of all that stuff right. This is again assuming the 206 00:11:24,360 --> 00:11:26,160 Speaker 1: universe is finite. If you go to the edge of 207 00:11:26,160 --> 00:11:28,560 Speaker 1: all that stuff, the argument doesn't hold anymore. You have 208 00:11:28,640 --> 00:11:31,240 Speaker 1: more stuff on one side than on the other. So 209 00:11:31,280 --> 00:11:34,280 Speaker 1: in the scenario of a finite universe, everything would be 210 00:11:34,320 --> 00:11:37,319 Speaker 1: attracted towards the center. Everything would be attracted towards the center. 211 00:11:37,600 --> 00:11:40,440 Speaker 1: All everyone, all the particles would just go towards the center. 212 00:11:40,960 --> 00:11:42,720 Speaker 1: And then what would happen? Man, I think it would 213 00:11:42,760 --> 00:11:45,559 Speaker 1: get like a huge star or a massive black hole, 214 00:11:45,679 --> 00:11:47,920 Speaker 1: or it would be a pretty crazy party, So the 215 00:11:48,000 --> 00:11:51,680 Speaker 1: universe would be just one star or one black hole. 216 00:11:51,840 --> 00:11:55,160 Speaker 1: I'm because I would be pretty complicated, but I think, yeah, 217 00:11:55,160 --> 00:11:58,400 Speaker 1: you would end up with one really big blob of matter, um, 218 00:11:58,400 --> 00:12:00,200 Speaker 1: and it would be you know, it wouldn't be compally 219 00:12:00,240 --> 00:12:03,920 Speaker 1: compressed into a point because matter resists being compressed and 220 00:12:03,920 --> 00:12:06,319 Speaker 1: and if it was spinning right then that keeps it 221 00:12:06,360 --> 00:12:09,920 Speaker 1: from being compressed further. Um. I don't know if anybody's 222 00:12:09,960 --> 00:12:11,719 Speaker 1: really studied what would happen if you just like had 223 00:12:11,720 --> 00:12:15,319 Speaker 1: a huge universized blob of finite matter and then let 224 00:12:15,360 --> 00:12:18,800 Speaker 1: it collapse. That would be fascinating. So it would be 225 00:12:19,040 --> 00:12:22,240 Speaker 1: kind of this one just one, not two, not three, 226 00:12:22,320 --> 00:12:25,400 Speaker 1: just one giant lump of stuff. That's right. And even 227 00:12:25,400 --> 00:12:29,400 Speaker 1: in that scenario where the universe is perfectly smooth but finite, right, 228 00:12:29,840 --> 00:12:33,400 Speaker 1: you can't get any asymmetries. Everything has to be perfectly 229 00:12:33,400 --> 00:12:35,920 Speaker 1: balanced in every direction. Right. Yes, you have a center, 230 00:12:35,960 --> 00:12:38,480 Speaker 1: so everything's attracted towards the center, but you can't like 231 00:12:39,000 --> 00:12:42,000 Speaker 1: make stars clumping along the way as they're getting dragged 232 00:12:42,000 --> 00:12:44,640 Speaker 1: towards the center. Still has to be perfectly smooth because 233 00:12:44,640 --> 00:12:47,240 Speaker 1: it's the same in every direction, right, In order to 234 00:12:47,280 --> 00:12:49,120 Speaker 1: get the kind of structure that we see when we 235 00:12:49,120 --> 00:12:50,720 Speaker 1: look at the night sky, you have like a star 236 00:12:50,800 --> 00:12:53,079 Speaker 1: here and no star there, and or galaxy here and 237 00:12:53,440 --> 00:12:57,079 Speaker 1: galaxy there. That's and those are asymmetry. So right, that's 238 00:12:57,080 --> 00:13:00,480 Speaker 1: a structure, that's a lump. Yeah, it's a in the 239 00:13:00,559 --> 00:13:03,720 Speaker 1: universe exactly. So that's obviously not the universe we're in. 240 00:13:03,800 --> 00:13:06,719 Speaker 1: We're not in a perfectly smooth, jelly universe, and we're 241 00:13:06,760 --> 00:13:12,080 Speaker 1: not living in one giant, singular super cluster of stuff. 242 00:13:12,720 --> 00:13:15,560 Speaker 1: We live in this kind of a stranger universe, right, 243 00:13:15,640 --> 00:13:17,320 Speaker 1: and thank god we do, right. I mean, it would 244 00:13:17,360 --> 00:13:20,000 Speaker 1: be pretty boring to live in an infinitely smooth pudding 245 00:13:20,559 --> 00:13:22,960 Speaker 1: or even just have like one big star living in 246 00:13:22,960 --> 00:13:26,720 Speaker 1: a perfect jelly. Seems pretty pretty peaceful to me. Again, 247 00:13:26,760 --> 00:13:28,440 Speaker 1: I think you should have a snack before we do 248 00:13:28,520 --> 00:13:31,240 Speaker 1: this podcast. Okay, although, as you tell you tend towards 249 00:13:31,240 --> 00:13:33,240 Speaker 1: these food analogies that I think it just reflects what 250 00:13:33,360 --> 00:13:37,439 Speaker 1: you're feeling rather than what you're thinking. Well, let's let's 251 00:13:37,720 --> 00:13:39,800 Speaker 1: get into how lumpy the universe is and how it 252 00:13:39,880 --> 00:13:42,360 Speaker 1: got that way. But first let's take a quick break. 253 00:13:54,880 --> 00:13:57,400 Speaker 1: All right, So we don't live in a perfectly smooth universe, 254 00:13:57,440 --> 00:13:59,280 Speaker 1: and we don't live in a universe such as one 255 00:13:59,480 --> 00:14:04,280 Speaker 1: giant cluster, black hole, slash star. That's not the universe 256 00:14:04,280 --> 00:14:06,319 Speaker 1: we'll live in, right, We are actually in a very 257 00:14:06,400 --> 00:14:09,520 Speaker 1: lumpy universe. Yeah, And the universe, the structure universe is 258 00:14:09,520 --> 00:14:12,280 Speaker 1: really fascinating. We should dig into it really deeply in 259 00:14:12,320 --> 00:14:14,560 Speaker 1: another podcast episode and talk about it and why it 260 00:14:14,640 --> 00:14:16,520 Speaker 1: is this way in that way. Um, but let's just 261 00:14:16,559 --> 00:14:19,360 Speaker 1: review briefly sort of where we are in the universe, 262 00:14:20,000 --> 00:14:23,840 Speaker 1: the the status of the lumps, the level of lumpiness 263 00:14:23,840 --> 00:14:26,080 Speaker 1: of the universe. Yeah, so we we are sitting here 264 00:14:26,120 --> 00:14:29,000 Speaker 1: on Earth presumably, that's right. We are two lumps on 265 00:14:29,040 --> 00:14:32,320 Speaker 1: a rock. Yeah. Um, presumably most of our listeners are 266 00:14:32,560 --> 00:14:34,240 Speaker 1: on Earth. And if you're not, by the way, if 267 00:14:34,240 --> 00:14:36,040 Speaker 1: you're listening to this podcast and you're not on Earth, 268 00:14:36,160 --> 00:14:40,480 Speaker 1: we really want to hear from you. Yeah. Absolutely, But 269 00:14:40,600 --> 00:14:43,160 Speaker 1: we are in a big rock around rock, going around 270 00:14:43,280 --> 00:14:47,320 Speaker 1: a sun, a star, and that's our solar system, right, 271 00:14:47,440 --> 00:14:49,880 Speaker 1: and even that is super lumpy. I mean from the 272 00:14:49,880 --> 00:14:52,680 Speaker 1: point of view of like how smooth this stuff distributed. 273 00:14:53,080 --> 00:14:55,200 Speaker 1: You know, people are probably familiar with how far away 274 00:14:55,240 --> 00:14:57,880 Speaker 1: the Sun is. It's you know, it takes a time 275 00:14:57,920 --> 00:15:00,000 Speaker 1: for light to even get there. It's minutes and minute, 276 00:15:00,000 --> 00:15:02,000 Speaker 1: it's in minutes, right, And the Sun itself is a 277 00:15:02,120 --> 00:15:05,560 Speaker 1: huge blov of matter, but it's super far away. You know. 278 00:15:05,640 --> 00:15:08,200 Speaker 1: The size of the Earth is enormous and the size 279 00:15:08,240 --> 00:15:09,800 Speaker 1: of the Sun is enormous, but the size of the 280 00:15:09,840 --> 00:15:14,040 Speaker 1: distance between them dwarfs both of them. Right, So even 281 00:15:14,080 --> 00:15:16,600 Speaker 1: just the solar system is really really lumpy in that 282 00:15:16,640 --> 00:15:19,280 Speaker 1: sense that the matter is concentrated and not spread out. 283 00:15:19,720 --> 00:15:22,640 Speaker 1: And then our solarcism is inside of a galaxy. Right, 284 00:15:23,640 --> 00:15:26,240 Speaker 1: and that's even lumpier from that point of view, right, 285 00:15:26,280 --> 00:15:29,960 Speaker 1: Like the distance between stars is huge compared to the 286 00:15:29,960 --> 00:15:32,720 Speaker 1: size of the stars. And it had some sort of structure, right, 287 00:15:32,720 --> 00:15:36,720 Speaker 1: Like the galaxy has spirals and it's kind of thicker 288 00:15:36,760 --> 00:15:39,280 Speaker 1: and more dense in the middle. Right, there's no structure 289 00:15:39,640 --> 00:15:42,120 Speaker 1: at that scale too. Yeah, the galaxy told me it 290 00:15:42,160 --> 00:15:44,520 Speaker 1: doesn't like when you talk about it's thickening waistline rhead. 291 00:15:45,000 --> 00:15:51,560 Speaker 1: But it's true. It sparkly. I'm talking about its sparkliness. 292 00:15:51,880 --> 00:15:55,040 Speaker 1: It's beautiful. It's beautiful, the milky way. Um, yeah, exactly. 293 00:15:55,040 --> 00:15:56,920 Speaker 1: We got all these stars, hundred billions of stars, but 294 00:15:56,960 --> 00:15:59,080 Speaker 1: they're not just a blob, right, They're not just distributed 295 00:15:59,160 --> 00:16:01,520 Speaker 1: evenly all THEO. For a long time people thought that's 296 00:16:01,280 --> 00:16:03,920 Speaker 1: what happened, But now we know that they're arranged in 297 00:16:03,920 --> 00:16:07,720 Speaker 1: this amazing swirl pattern right or the center of the galaxy. 298 00:16:07,760 --> 00:16:09,400 Speaker 1: And then we have these arms that come out and 299 00:16:09,440 --> 00:16:12,760 Speaker 1: because it's rotating, those arms sort of dragged behind it, 300 00:16:13,320 --> 00:16:15,560 Speaker 1: and uh, and you get this amazing swirl and then 301 00:16:15,560 --> 00:16:17,960 Speaker 1: you can keep going like the galaxy is part of 302 00:16:17,960 --> 00:16:21,480 Speaker 1: a supercluster of galaxies and that's super. No, you missed one? 303 00:16:21,680 --> 00:16:23,720 Speaker 1: What you missed one? The galaxy is part of a 304 00:16:23,760 --> 00:16:26,880 Speaker 1: cluster of galaxies, right, And when we talk about a cluster, 305 00:16:27,000 --> 00:16:29,920 Speaker 1: we mean things that are gravitationally bound to each other, 306 00:16:29,960 --> 00:16:32,960 Speaker 1: that essentially are orbiting each other over billions and billions 307 00:16:33,000 --> 00:16:36,320 Speaker 1: of years. So we and ours is called the local group, 308 00:16:36,440 --> 00:16:40,000 Speaker 1: right Like our cluster of galaxies is very imaginatively called 309 00:16:40,040 --> 00:16:43,400 Speaker 1: the local group. I know that sounds like a temporary 310 00:16:43,480 --> 00:16:45,240 Speaker 1: name somebody came up with, like, oh, I need to 311 00:16:45,280 --> 00:16:47,400 Speaker 1: call this something and talk to my advisor, and then 312 00:16:47,400 --> 00:16:49,120 Speaker 1: it just stuck and they're like, dang, and I should 313 00:16:49,160 --> 00:16:52,960 Speaker 1: have named it after my dog. What's the opposite of local? 314 00:16:53,200 --> 00:16:57,520 Speaker 1: Like basically, just here, it means the galaxies near us, right, 315 00:16:58,040 --> 00:17:02,520 Speaker 1: It's pretty lame name. Um yeah, so that's the cluster. 316 00:17:03,000 --> 00:17:05,760 Speaker 1: You know, our galaxy cluster is green and you know 317 00:17:06,520 --> 00:17:12,480 Speaker 1: local sources locally, that's right. I don't think it's vegan, 318 00:17:12,800 --> 00:17:22,160 Speaker 1: but at least it's local, right. Um yeah, exactly. Our 319 00:17:22,200 --> 00:17:24,879 Speaker 1: galaxy is part of a structure of of other with 320 00:17:25,040 --> 00:17:29,920 Speaker 1: other galaxies. Even that cluster is part of another structure 321 00:17:29,960 --> 00:17:33,000 Speaker 1: in the universe, right. Yeah. They call those superclusters, and 322 00:17:33,040 --> 00:17:37,560 Speaker 1: these are basically clusters of clusters another imaginative name. Huh. 323 00:17:37,680 --> 00:17:39,920 Speaker 1: And again you might ask, like, are these totally arbitrary? 324 00:17:39,920 --> 00:17:42,080 Speaker 1: Is just making this up? Could you have organized it differently? 325 00:17:42,280 --> 00:17:44,640 Speaker 1: The answers, No, there's some science behind it. We think 326 00:17:44,680 --> 00:17:48,159 Speaker 1: about how these groups operate, you know, And essentially a 327 00:17:48,240 --> 00:17:52,000 Speaker 1: supercluster is not just a really really big cluster, it's 328 00:17:52,080 --> 00:17:56,000 Speaker 1: a cluster of clusters, meaning that the each cluster inside 329 00:17:56,000 --> 00:17:59,720 Speaker 1: a supercluster is gravitationally bound to itself, and then those 330 00:17:59,760 --> 00:18:02,880 Speaker 1: things themselves are gravitationally bound to each other, and that's 331 00:18:02,880 --> 00:18:05,199 Speaker 1: what makes the super clustered. They're sort of trapped in 332 00:18:05,240 --> 00:18:08,520 Speaker 1: a sort of gravitational bubble almost. Yeah, the way like 333 00:18:08,760 --> 00:18:11,280 Speaker 1: you know, the Earth and the Moon are a gravitational system, right, 334 00:18:11,280 --> 00:18:13,880 Speaker 1: which is embedded inside the Solar System, which is embedded 335 00:18:13,880 --> 00:18:17,000 Speaker 1: inside the galaxy. Right, you might say it's arbitrary to 336 00:18:17,040 --> 00:18:18,760 Speaker 1: define whether or not the Moon is part of the 337 00:18:18,760 --> 00:18:20,760 Speaker 1: Earth system, of the Solar System, whatever. Really makes much 338 00:18:20,760 --> 00:18:22,919 Speaker 1: more sense to consider the Earth to be part of 339 00:18:22,960 --> 00:18:25,239 Speaker 1: our system, and then the Solar System may be part 340 00:18:25,280 --> 00:18:27,280 Speaker 1: of the galaxy, rather than just say like, oh, it's 341 00:18:27,280 --> 00:18:30,439 Speaker 1: all one big galaxy. So that's why we get these hierarchies, 342 00:18:30,640 --> 00:18:32,639 Speaker 1: and it's amazing that we have these hierarchies, you know, 343 00:18:32,680 --> 00:18:34,840 Speaker 1: and like also because you can zoom down right and 344 00:18:34,840 --> 00:18:36,719 Speaker 1: you get like down to the atom and things are 345 00:18:36,800 --> 00:18:39,840 Speaker 1: orbiting and stuff. So we have this over incredible the 346 00:18:40,000 --> 00:18:45,400 Speaker 1: different distances from microscopic to what megascopic we have similar 347 00:18:45,400 --> 00:18:47,800 Speaker 1: structures of things orbiting each other and right on these 348 00:18:47,840 --> 00:18:51,080 Speaker 1: on these large scales, like an infinite Russian doll, you 349 00:18:51,119 --> 00:18:54,280 Speaker 1: can stack them up almost infinitely, seems yeah, but infinite, 350 00:18:54,280 --> 00:18:56,120 Speaker 1: we don't know, right, We talked about that another time, 351 00:18:56,160 --> 00:18:59,800 Speaker 1: Like we think the universe probably has the smallest scale, 352 00:19:00,119 --> 00:19:02,480 Speaker 1: and when we talk about the structure of the galaxy 353 00:19:02,560 --> 00:19:04,720 Speaker 1: as the structure of the the universe, and another podcast episode 354 00:19:04,720 --> 00:19:07,240 Speaker 1: we'll talk about the biggest structures in the university is 355 00:19:07,280 --> 00:19:09,720 Speaker 1: a whole other fascinating topic. You can keep going in. 356 00:19:09,720 --> 00:19:12,080 Speaker 1: There are bigger, bigger structures, right. Well, there's a point 357 00:19:12,080 --> 00:19:15,560 Speaker 1: where they stop. Yeah, at some point they stop. At 358 00:19:15,600 --> 00:19:19,119 Speaker 1: some point they stop. There's an end to the Russian doll, 359 00:19:19,280 --> 00:19:21,600 Speaker 1: as far as we know, there is. There's the largest 360 00:19:21,640 --> 00:19:23,960 Speaker 1: Russian doll. Yeah. Um, anyway, but that's the topic for 361 00:19:24,000 --> 00:19:28,200 Speaker 1: another another day. Let's talk about why why we have structure. Yeah, 362 00:19:28,200 --> 00:19:30,080 Speaker 1: the point is that there is structure, right, Like, we're 363 00:19:30,119 --> 00:19:32,880 Speaker 1: not in a smooth universe and we're not just one 364 00:19:32,920 --> 00:19:36,520 Speaker 1: giant lump. There is like texture to the universe, right, 365 00:19:36,520 --> 00:19:40,399 Speaker 1: there's features, there's things to look at, there's good stuff 366 00:19:40,440 --> 00:19:44,960 Speaker 1: to see exactly, and as our you see I question 367 00:19:45,040 --> 00:19:49,240 Speaker 1: answers earlier said gravity is responsible for forming those things. 368 00:19:49,240 --> 00:19:52,000 Speaker 1: But gravity couldn't start those structures, right, That was the 369 00:19:52,000 --> 00:19:54,480 Speaker 1: point we were making earlier. So the point is that 370 00:19:54,520 --> 00:19:57,960 Speaker 1: gravity can't make lumps. When you start a lump, gravity 371 00:19:57,960 --> 00:20:00,399 Speaker 1: will accelerate like a chain reaction. Right, when you have 372 00:20:00,520 --> 00:20:03,119 Speaker 1: one point that's denser than everything else, it will have 373 00:20:03,160 --> 00:20:06,320 Speaker 1: a stronger gravitational pull and it'll start to attract stuff 374 00:20:06,359 --> 00:20:09,080 Speaker 1: and then look at heavier and have a stronger gravitational pull, 375 00:20:09,359 --> 00:20:11,919 Speaker 1: and it will feed on itself. But if everything is smooth, 376 00:20:12,000 --> 00:20:14,400 Speaker 1: then you can't. So the question is, so gravity can 377 00:20:14,400 --> 00:20:17,600 Speaker 1: make lumps bigger, but the question really comes down to 378 00:20:17,880 --> 00:20:20,119 Speaker 1: where did the first lumps come from. It's kind of 379 00:20:20,160 --> 00:20:23,760 Speaker 1: like gravity can roll a snowball down the hill, but 380 00:20:23,840 --> 00:20:28,320 Speaker 1: it can't sort of start the snowball rolling, Yeah, exactly, exactly, 381 00:20:28,359 --> 00:20:30,360 Speaker 1: Like once it's rolling, it gets bigger and lump here. 382 00:20:30,400 --> 00:20:33,560 Speaker 1: But you need some sort of something to get that 383 00:20:33,640 --> 00:20:35,760 Speaker 1: snowball going. Yeah, you have to knock it out of 384 00:20:35,800 --> 00:20:41,920 Speaker 1: equilibrium to get it to get things snowballing exactly. Okay, 385 00:20:44,480 --> 00:20:47,000 Speaker 1: all right, So how did the universe key head lumps? 386 00:20:47,320 --> 00:20:50,560 Speaker 1: How is it not perfectly smooth or one giant? So 387 00:20:50,600 --> 00:20:52,479 Speaker 1: that was a big mystery for a long time, right, 388 00:20:52,520 --> 00:20:55,840 Speaker 1: because it's very natural to think that the universe started symmetrically. 389 00:20:56,160 --> 00:20:58,119 Speaker 1: I think probably the most popular model for how the 390 00:20:58,160 --> 00:21:01,680 Speaker 1: universe started is the universe versus infinite and that has 391 00:21:01,760 --> 00:21:03,920 Speaker 1: infinite amount of matter in it, and that was created 392 00:21:03,920 --> 00:21:07,240 Speaker 1: in the first moments, right that we don't understand at all. 393 00:21:07,680 --> 00:21:09,800 Speaker 1: But not understanding it means we want to start with 394 00:21:09,840 --> 00:21:12,600 Speaker 1: the simplest idea. Okay, And it's not very simple to 395 00:21:12,640 --> 00:21:14,760 Speaker 1: imagine the creation of an infinite universe with an infinite 396 00:21:14,760 --> 00:21:16,720 Speaker 1: amount of stuff in it. But if you're gonna go there, 397 00:21:17,200 --> 00:21:19,359 Speaker 1: it makes more sense to say that the universe starts 398 00:21:19,359 --> 00:21:22,360 Speaker 1: out smooth. That's where this idea of smoothness comes right, right, 399 00:21:22,400 --> 00:21:26,080 Speaker 1: like simplicity, because the opposite like, oh, that the universe 400 00:21:26,160 --> 00:21:28,679 Speaker 1: was created with some initial lumpiness, that's weird. Because then 401 00:21:28,720 --> 00:21:31,320 Speaker 1: you have to ask why this lumpingness, Why not that lumpiness? 402 00:21:31,359 --> 00:21:34,200 Speaker 1: Who made that choice? Right? And uh so it was 403 00:21:34,240 --> 00:21:37,840 Speaker 1: a big puzzle for a long time. Um, And there's 404 00:21:37,840 --> 00:21:40,159 Speaker 1: really only one way that we know of that you 405 00:21:40,200 --> 00:21:44,160 Speaker 1: can make lumpiness out of smoothness. There's only one thing 406 00:21:44,200 --> 00:21:47,560 Speaker 1: in physics that's capable of doing that, Meaning there's only 407 00:21:47,640 --> 00:21:51,840 Speaker 1: one thing they can add features to something that should 408 00:21:51,920 --> 00:21:55,560 Speaker 1: be perfectly plain. That's right, what you need there's something 409 00:21:55,600 --> 00:22:00,400 Speaker 1: that's not deterministic, something which has a random element to it, right, 410 00:22:00,400 --> 00:22:03,280 Speaker 1: because if every particle universe starts in the same situation, 411 00:22:03,520 --> 00:22:05,520 Speaker 1: then they should all have the same future. Which you 412 00:22:05,560 --> 00:22:07,679 Speaker 1: need is to distinguish them somehow, for this one have 413 00:22:07,720 --> 00:22:09,520 Speaker 1: a different future than that one, for this one, have 414 00:22:09,520 --> 00:22:12,320 Speaker 1: a different experience somehow. The only thing we know they 415 00:22:12,359 --> 00:22:15,680 Speaker 1: can do that that can break determinism is quantum mechanics. 416 00:22:15,720 --> 00:22:20,240 Speaker 1: Because quantum mechanics has real randomness in it. Is that 417 00:22:20,320 --> 00:22:23,520 Speaker 1: the source then of randomness in the universe. Like without 418 00:22:23,600 --> 00:22:27,760 Speaker 1: quantum mechanics, we would all be perfectly smooth. Yeah, exactly, 419 00:22:27,840 --> 00:22:30,040 Speaker 1: But there was still another puzzle, right, So quantum mechanics 420 00:22:30,080 --> 00:22:32,480 Speaker 1: gives you randomness, but you know, quantum mechanics does not 421 00:22:32,520 --> 00:22:35,439 Speaker 1: something you notice. You don't like drive around and notice 422 00:22:35,600 --> 00:22:38,600 Speaker 1: random stuff happening from quantum mechannicals, Like if my phone 423 00:22:38,680 --> 00:22:41,800 Speaker 1: is here, it's not here and there, that's right. I mean, 424 00:22:41,840 --> 00:22:44,320 Speaker 1: maybe your bank accounts seems to fluctuate randomly, but there 425 00:22:44,320 --> 00:22:48,120 Speaker 1: actually is an explanation. My bank account could use more physics, 426 00:22:48,119 --> 00:22:53,919 Speaker 1: for sure. I am a quantum mechanic accountant, quantom accountant 427 00:22:54,560 --> 00:22:56,960 Speaker 1: um exactly. And that's why quantum mechanics took such a 428 00:22:57,000 --> 00:23:00,000 Speaker 1: long time to discover, because people thought the universe was deterministic. 429 00:23:00,000 --> 00:23:02,720 Speaker 1: I thought two particles in the same situation would always 430 00:23:02,760 --> 00:23:05,199 Speaker 1: have the same future. I see, there's no reason for 431 00:23:05,240 --> 00:23:08,080 Speaker 1: them to be different. Like if you create a universe 432 00:23:08,840 --> 00:23:11,879 Speaker 1: without quantum mechanics, there's no reason for all the particles 433 00:23:11,920 --> 00:23:14,240 Speaker 1: to be different. There's nothing that gives it that initial 434 00:23:14,680 --> 00:23:19,280 Speaker 1: randomness exactly. The problem is that quantum mechanics is a 435 00:23:19,280 --> 00:23:22,320 Speaker 1: tiny amount of randomness, right, it's at the particle scale. 436 00:23:22,600 --> 00:23:26,159 Speaker 1: It's super duper small, right, these tiny little fluctuations, And 437 00:23:26,200 --> 00:23:28,320 Speaker 1: what are we talking about concretely, we're talking about like 438 00:23:28,840 --> 00:23:31,560 Speaker 1: particles being created out of the vacuum. Quantum mechanics can 439 00:23:31,560 --> 00:23:33,720 Speaker 1: do that. It can take energy and just turn it 440 00:23:33,720 --> 00:23:35,879 Speaker 1: into particles and then they can turn back into energy. 441 00:23:36,520 --> 00:23:38,800 Speaker 1: Or you know, this particle can have a chance to 442 00:23:38,880 --> 00:23:40,719 Speaker 1: go left or right, and you know, maybe this one 443 00:23:40,760 --> 00:23:43,080 Speaker 1: goes left and another one goes right. This kind of stuff, 444 00:23:43,080 --> 00:23:46,880 Speaker 1: it's really really tiny effects, not really enough to get 445 00:23:46,880 --> 00:23:50,440 Speaker 1: gravity going because gravity is super duper weak, right, Gravity 446 00:23:50,480 --> 00:23:54,240 Speaker 1: needs more than the tiniest little discrepancy. I mean, if 447 00:23:54,240 --> 00:23:56,440 Speaker 1: you've given billions of years. But the kicker is that 448 00:23:56,480 --> 00:23:58,879 Speaker 1: the universe used to be small, right, that's the twist. 449 00:23:59,000 --> 00:24:01,600 Speaker 1: Ending is that the universe used to be really tiny 450 00:24:01,640 --> 00:24:04,400 Speaker 1: and small. That's right, And so the very first moments 451 00:24:04,400 --> 00:24:07,240 Speaker 1: of the universe were super dramatic. What happened in the 452 00:24:07,280 --> 00:24:10,960 Speaker 1: first first moments of the universe was inflation. Inflation is 453 00:24:11,000 --> 00:24:14,120 Speaker 1: this idea that the universe used to be much denser 454 00:24:14,400 --> 00:24:17,000 Speaker 1: and then it got stretched out, it got inflated, right, 455 00:24:17,040 --> 00:24:19,840 Speaker 1: And that's just not stuff moving through space. This is 456 00:24:19,880 --> 00:24:23,720 Speaker 1: the actual expansion of space itself, meaning things got stretched right, 457 00:24:24,160 --> 00:24:27,119 Speaker 1: more space was made everything I'm blown and inflated and 458 00:24:27,119 --> 00:24:32,520 Speaker 1: blown up. What that means is that the microscopic became macroscopic. 459 00:24:32,800 --> 00:24:34,879 Speaker 1: We'll step us through this. So you're saying, this is 460 00:24:34,920 --> 00:24:37,440 Speaker 1: all this all goes back to the Big Bang, right, 461 00:24:37,640 --> 00:24:39,239 Speaker 1: Everything goes back to the Big Bang in the end. 462 00:24:39,240 --> 00:24:41,760 Speaker 1: You can blame everything in the Big Bang technically, I 463 00:24:41,800 --> 00:24:46,040 Speaker 1: guess yeah, um officer, I was speeding because the Big 464 00:24:46,040 --> 00:24:51,320 Speaker 1: Bang dot dot dot dot dot. I blame the universe. YadA, YadA, YadA, 465 00:24:51,320 --> 00:24:56,040 Speaker 1: I was speeding quantum mechanics. That gets me out of 466 00:24:56,040 --> 00:24:58,600 Speaker 1: every ticket, trust me. Before we keep going, let's take 467 00:24:58,640 --> 00:25:14,200 Speaker 1: a short break. Yeah, so the universe used to be very, 468 00:25:14,280 --> 00:25:17,119 Speaker 1: very small, and that's where these that's where quantum mechanics 469 00:25:17,119 --> 00:25:18,959 Speaker 1: played a big role, right, Yeah, And be careful when 470 00:25:19,000 --> 00:25:20,840 Speaker 1: you say the universe used to be very small, because 471 00:25:20,840 --> 00:25:23,480 Speaker 1: we're still saying the universe was infinite, right, and an 472 00:25:23,480 --> 00:25:26,359 Speaker 1: infinite amount of stuff in it, but it was denser, right. 473 00:25:26,359 --> 00:25:29,280 Speaker 1: It used to be more squished when it was created, 474 00:25:29,359 --> 00:25:30,960 Speaker 1: and then it was and then all that stuff was 475 00:25:31,040 --> 00:25:34,840 Speaker 1: stretched out due to inflation. Oh. I see, So it's 476 00:25:34,880 --> 00:25:37,640 Speaker 1: like an infinite ruler getting stretched. It's still infinite, right, 477 00:25:37,960 --> 00:25:40,360 Speaker 1: I see. So you're saying that the features we've see 478 00:25:40,359 --> 00:25:45,480 Speaker 1: in the universe today are really just the quantum features 479 00:25:45,520 --> 00:25:49,160 Speaker 1: that we used to have when we were denser, not smaller. 480 00:25:49,800 --> 00:25:52,720 Speaker 1: But now when inflation happened at the Big Bang, everything 481 00:25:52,760 --> 00:25:56,240 Speaker 1: all these small fluctuations got way way bigger. Yeah, it's 482 00:25:56,320 --> 00:25:59,000 Speaker 1: like an ant man right where he can. He can 483 00:25:59,119 --> 00:26:01,640 Speaker 1: make things much much of it. Right, ants can be enormous, 484 00:26:01,680 --> 00:26:03,840 Speaker 1: and then they can do construction projects and you can 485 00:26:04,080 --> 00:26:06,119 Speaker 1: ride in the back of a butterfly and cool stuff. 486 00:26:06,600 --> 00:26:10,399 Speaker 1: Take the microscopic and make it macroscopic. Right, So the 487 00:26:10,400 --> 00:26:15,679 Speaker 1: timeline is the universe is created perfectly smooth, right, little 488 00:26:15,760 --> 00:26:19,160 Speaker 1: quantum fluctuations happen a little bit this, one particle moves 489 00:26:19,160 --> 00:26:20,960 Speaker 1: a little bit this way, one particle moves a little 490 00:26:20,960 --> 00:26:24,679 Speaker 1: bit that way. Then inflation takes over and blows that 491 00:26:24,840 --> 00:26:28,960 Speaker 1: up right and inflates. It makes those tiny little fluctuations 492 00:26:29,000 --> 00:26:33,160 Speaker 1: into bigger fluctuations enough to see gravity, and then gravity 493 00:26:33,200 --> 00:26:36,639 Speaker 1: takes over for the next fourteen billion years. YadA, YadA, YadA. 494 00:26:36,680 --> 00:26:43,359 Speaker 1: I was speeding officer. I'm telling you that story works 495 00:26:43,400 --> 00:26:46,960 Speaker 1: every time. Yeah, they probably fall asleep before you finish. 496 00:26:48,760 --> 00:26:54,840 Speaker 1: Another physics professor, you just let him go. So you're saying, 497 00:26:55,000 --> 00:26:58,040 Speaker 1: the universe used to be small or denser, and and 498 00:26:58,119 --> 00:27:02,359 Speaker 1: everything was smoother at that scale, except that if we 499 00:27:02,400 --> 00:27:05,440 Speaker 1: didn't have quantum mechanics, but we still had inflation. Then 500 00:27:05,520 --> 00:27:09,000 Speaker 1: we would have exploded the universe or expanded universe, and 501 00:27:09,119 --> 00:27:12,440 Speaker 1: it would remain smooth. Yes, exactly, it would remain smooth 502 00:27:13,040 --> 00:27:15,479 Speaker 1: because we had those quantum fluctuations that a little bit 503 00:27:15,480 --> 00:27:19,639 Speaker 1: of random this at the beginning gave the universe texture exactly. 504 00:27:19,920 --> 00:27:22,840 Speaker 1: And those little fluctuations were random, right, and they could 505 00:27:22,840 --> 00:27:26,160 Speaker 1: have been different, different random throws of the universe dice, 506 00:27:26,400 --> 00:27:28,560 Speaker 1: and we would have a completely different structure. I mean, 507 00:27:28,760 --> 00:27:31,040 Speaker 1: I think the kinds of structures we would have would 508 00:27:31,080 --> 00:27:33,560 Speaker 1: still be the same. We would still have galaxies and stars, whatever, 509 00:27:33,720 --> 00:27:35,960 Speaker 1: but they would be arranged differently. So you might ask, 510 00:27:36,160 --> 00:27:38,840 Speaker 1: why do we have a galaxy here and not there? 511 00:27:39,080 --> 00:27:41,520 Speaker 1: And you can trace the answer that all the way 512 00:27:41,560 --> 00:27:46,280 Speaker 1: back to one little particle fluctuating my millibil of seconds 513 00:27:46,359 --> 00:27:48,760 Speaker 1: after the Big Bang. If it fluctuated this way, we 514 00:27:48,840 --> 00:27:51,000 Speaker 1: get this galaxy. We fluctuated that way, we get a 515 00:27:51,040 --> 00:27:53,600 Speaker 1: different galaxy, or in the same galaxy in a different place. 516 00:27:54,400 --> 00:27:58,000 Speaker 1: That you said that that provided the seeds for the structure, 517 00:27:58,080 --> 00:28:01,040 Speaker 1: meaning it would have and it expanded, it would have 518 00:28:01,080 --> 00:28:04,440 Speaker 1: been smooth, but it had these kind of slightly small 519 00:28:04,960 --> 00:28:09,160 Speaker 1: shades of a texture, and those those shades became exaggerated 520 00:28:09,160 --> 00:28:11,600 Speaker 1: by gravity, and then things started to clump around those 521 00:28:11,760 --> 00:28:14,679 Speaker 1: little shades of texture exactly. And we can see this. 522 00:28:14,760 --> 00:28:16,800 Speaker 1: We can look back in time and we can see 523 00:28:16,840 --> 00:28:20,040 Speaker 1: this progression happening. Like if you look back deep, deep 524 00:28:20,040 --> 00:28:22,199 Speaker 1: into the history of the universe, you see the first 525 00:28:22,320 --> 00:28:24,600 Speaker 1: light that we can see, which comes from about three 526 00:28:25,040 --> 00:28:27,480 Speaker 1: eighty thousand years after the Big Bang. It's the cosmic 527 00:28:27,520 --> 00:28:30,520 Speaker 1: microwave background. We've talked about a few times. This light 528 00:28:30,640 --> 00:28:33,000 Speaker 1: is really really smooth. It's almost the same no matter 529 00:28:33,080 --> 00:28:34,680 Speaker 1: where you look at it. It's like the same color, 530 00:28:34,800 --> 00:28:37,960 Speaker 1: the same temperature, whatever. But if you measure it really 531 00:28:38,080 --> 00:28:42,560 Speaker 1: carefully that you can see little variations, tiny little fractions 532 00:28:43,000 --> 00:28:46,520 Speaker 1: of colder and hotter spots. Those that took four hundred 533 00:28:46,520 --> 00:28:49,680 Speaker 1: thousand years just to get that far right, those are 534 00:28:49,800 --> 00:28:53,960 Speaker 1: the seeds of from this quantum fluctuations exaggerated by gravity 535 00:28:54,000 --> 00:28:56,840 Speaker 1: for four hundred thousand years, then propagated forward in time. 536 00:28:56,880 --> 00:28:59,280 Speaker 1: Give gravity another few billion years, and you start to 537 00:28:59,320 --> 00:29:02,280 Speaker 1: get things like stars and galaxies and all that stuff. Right, 538 00:29:02,400 --> 00:29:05,440 Speaker 1: But we can see these quantum fluctuations from the early universe. 539 00:29:05,440 --> 00:29:10,239 Speaker 1: It's like the pattern that made our our cosmos was 540 00:29:10,280 --> 00:29:13,800 Speaker 1: totally random. It was totally random, exactly. And we think 541 00:29:13,920 --> 00:29:17,320 Speaker 1: quantum mechanics is truly random, right, not like there's some 542 00:29:17,440 --> 00:29:20,040 Speaker 1: hidden process that's controlling it that we don't understand. We 543 00:29:20,080 --> 00:29:22,600 Speaker 1: think it's really truly random. As mind blowing as it 544 00:29:22,680 --> 00:29:25,920 Speaker 1: is for anything in the universe to be honestly truly random, 545 00:29:26,240 --> 00:29:29,040 Speaker 1: it is, and it affects our universe is structure at 546 00:29:29,080 --> 00:29:32,600 Speaker 1: the deepest level. Right. Wow, it's amazing to think that 547 00:29:32,640 --> 00:29:34,880 Speaker 1: the reason you and I are here, or the whole 548 00:29:34,880 --> 00:29:37,560 Speaker 1: Earth this year, or the whole Sun and our solericism, 549 00:29:37,600 --> 00:29:40,240 Speaker 1: or even maybe even our galaxies here is just the 550 00:29:40,240 --> 00:29:43,960 Speaker 1: the random fluctuation of one little tiny particle way back 551 00:29:43,960 --> 00:29:46,720 Speaker 1: in the Big Bang. Yeah, it's the truth, man, The 552 00:29:46,720 --> 00:29:49,880 Speaker 1: truth is stranger than fiction. That's why. That's why I'm 553 00:29:49,880 --> 00:29:53,000 Speaker 1: a physicist, because you know, the universe will always alarm you. 554 00:29:53,200 --> 00:29:56,480 Speaker 1: The universe is like weirder and hotter and nastier and 555 00:29:56,560 --> 00:30:01,440 Speaker 1: crazier and stranger than anything human could or invent. Right, Well, 556 00:30:01,480 --> 00:30:04,760 Speaker 1: depends on how crazy and weird you are. But how 557 00:30:04,840 --> 00:30:10,440 Speaker 1: hot and where you are that's a whole different podcast. 558 00:30:15,480 --> 00:30:18,160 Speaker 1: So um, I'll have to play this podcast for my son, 559 00:30:18,240 --> 00:30:20,920 Speaker 1: But that basically answers this question, right, like why do 560 00:30:20,960 --> 00:30:23,600 Speaker 1: we have stars and not to the smooth distribution of matter, 561 00:30:23,720 --> 00:30:26,760 Speaker 1: you need two elements. You need quantum mechanics to give 562 00:30:26,800 --> 00:30:29,760 Speaker 1: you any fluctuation to avoid the smoothness, to break the 563 00:30:30,040 --> 00:30:32,440 Speaker 1: balance exactly, to break the balance, and then you need 564 00:30:32,640 --> 00:30:35,360 Speaker 1: inflation to blow it up so that it matters, and 565 00:30:35,400 --> 00:30:38,320 Speaker 1: that gravity can then take over. So it's a complicated 566 00:30:38,400 --> 00:30:43,440 Speaker 1: dance to Gravity takes these small fluctuations and basically exacerbates them, right, 567 00:30:43,440 --> 00:30:48,600 Speaker 1: it makes them, yeah, lumpier and clumpier than than it started. Yeah, 568 00:30:48,640 --> 00:30:50,719 Speaker 1: but remember gravity can only take little lumps and make 569 00:30:50,720 --> 00:30:53,840 Speaker 1: them into bigger lumps, right, It can't make lumps if 570 00:30:53,880 --> 00:30:58,120 Speaker 1: something is totally smooth. All right. Thanks to everyone for 571 00:30:58,160 --> 00:31:01,320 Speaker 1: listening to this lumpy episode and for listening to my 572 00:31:01,440 --> 00:31:05,200 Speaker 1: long explanation to my son's short question. Yeah, and whether 573 00:31:05,280 --> 00:31:09,040 Speaker 1: you're a movie star like Tom Cruise or just a 574 00:31:09,160 --> 00:31:12,400 Speaker 1: scruffy physicists, if you have any question or lumpy or 575 00:31:12,400 --> 00:31:15,120 Speaker 1: smooth or why or why do you have to be 576 00:31:15,360 --> 00:31:17,880 Speaker 1: a movie star or a scruffy physicist? Are you saying 577 00:31:17,880 --> 00:31:23,600 Speaker 1: you can't be both? That that no you can totally 578 00:31:23,680 --> 00:31:27,000 Speaker 1: be both. Totally. Yeah, don't ask me for a counterexample. 579 00:31:27,040 --> 00:31:29,320 Speaker 1: I can't think of one. Maybe maybe in another random 580 00:31:29,440 --> 00:31:32,600 Speaker 1: role of the universe. That's right. Why are you not 581 00:31:32,680 --> 00:31:39,239 Speaker 1: a movie star? Dad? Quantum mechanics, So whether you are 582 00:31:39,280 --> 00:31:41,720 Speaker 1: any of these things, if you have any questions, but 583 00:31:41,800 --> 00:31:45,160 Speaker 1: you can write us at feedback at Daniel and Jorge 584 00:31:45,320 --> 00:31:47,880 Speaker 1: dot com. We love getting your email, We love answering 585 00:31:47,960 --> 00:31:51,479 Speaker 1: questions on Twitter, so get in touch, send us your thoughts. 586 00:31:51,640 --> 00:31:53,040 Speaker 1: And so the next time you look out into the 587 00:31:53,160 --> 00:31:55,680 Speaker 1: night sky and you see all those sparkly stars, just 588 00:31:55,760 --> 00:31:59,520 Speaker 1: think everything is there. You are there because the one 589 00:32:00,000 --> 00:32:02,080 Speaker 1: and them part of them. But you still have to 590 00:32:02,080 --> 00:32:05,400 Speaker 1: pay your taxes and your speeding tickets unless you can 591 00:32:05,400 --> 00:32:16,920 Speaker 1: talk your way out of them. If you still have 592 00:32:16,960 --> 00:32:20,360 Speaker 1: a question after listening to all these explanations, please drop 593 00:32:20,440 --> 00:32:22,520 Speaker 1: us a line. We'd love to hear from you. You 594 00:32:22,520 --> 00:32:25,959 Speaker 1: can find us at Facebook, Twitter, and Instagram at Daniel 595 00:32:26,000 --> 00:32:29,520 Speaker 1: and Jorge That's one word, or email us at feedback 596 00:32:29,560 --> 00:32:40,520 Speaker 1: at Daniel and Orge dot com.