1 00:00:00,040 --> 00:00:02,799 Speaker 1: I want to start today with a bit of a 2 00:00:02,879 --> 00:00:05,559 visualization exercise. Oh okay, I know, I know. Usually we 3 00:00:05,639 --> 00:00:08,279 just jump right in, but trust me on this one. 4 00:00:08,320 --> 00:00:11,000 I want you to close your eyes unless you are driving, 5 00:00:11,759 --> 00:00:14,960 in which case, please, for the love of physics, keep 6 00:00:15,000 --> 00:00:17,359 them open. I want you to picture. 7 00:00:17,079 --> 00:00:20,079 Speaker 2: The universe, all right, I'm picturing it the void. 8 00:00:20,399 --> 00:00:22,399 Speaker 1: What do you see? What's in that void? Uh? 9 00:00:22,480 --> 00:00:26,519 Speaker 2: The usual, you know, a vast infinite blackness. Maybe some 10 00:00:26,559 --> 00:00:30,559 scattered diamond dust, which you know that represents the stars. Sure, 11 00:00:30,719 --> 00:00:33,079 maybe a spiral galaxy or two floating in the distance 12 00:00:33,200 --> 00:00:37,200 like frisbees. It's mostly empty, right, that's the main takeaway. 13 00:00:36,799 --> 00:00:40,560 Speaker 1: Right, that's the classic view, kind of random speckled darkness. 14 00:00:41,079 --> 00:00:43,359 But I want you to wipe that image away, just deleted. 15 00:00:43,719 --> 00:00:49,399 I want you to replace that majestic, silent void with something, well, something. 16 00:00:49,240 --> 00:00:52,240 Speaker 2: Uglier, uglier. I mean, how can the universe be ugly? 17 00:00:52,399 --> 00:00:52,920 Speaker 1: Oh? It can? 18 00:00:53,159 --> 00:00:53,399 Speaker 2: Yeah. 19 00:00:53,520 --> 00:00:54,920 Speaker 1: I want you to picture an orc. 20 00:00:54,960 --> 00:00:58,240 Speaker 2: An orc, an orc like from a fantasy novel, green skin, 21 00:00:58,560 --> 00:01:02,880 protruding tusks, holding a crude club, ready to rate a village. 22 00:01:03,399 --> 00:01:06,519 Speaker 1: That kind of work, exactly, that kind of ork. Because, 23 00:01:06,560 --> 00:01:09,239 according to a stunning new paper we are breaking down today. 24 00:01:09,719 --> 00:01:13,079 If you look at the structure of our specific corner 25 00:01:13,120 --> 00:01:15,959 of the universe, I mean the distribution of matter and 26 00:01:16,000 --> 00:01:19,000 the void surrounding us, and you visualize it just right, 27 00:01:19,840 --> 00:01:23,200 the universe is making a face at us, and that 28 00:01:23,319 --> 00:01:24,719 face looks like an orc. 29 00:01:24,920 --> 00:01:27,719 Speaker 2: It sounds absolutely ridiculous when you say it out loud, 30 00:01:27,799 --> 00:01:30,680 It really does. It sounds like we've completely lost our minds, 31 00:01:30,760 --> 00:01:33,480 I know. But the physics behind that image, the density 32 00:01:33,560 --> 00:01:37,519 maps that actually create that face, are incredibly serious. 33 00:01:37,599 --> 00:01:40,159 Speaker 1: And here's the kicker and the real reason we are 34 00:01:40,159 --> 00:01:43,439 doing this show today. That orc face implies that we 35 00:01:43,480 --> 00:01:45,000 are living in a cosmic sandwich. 36 00:01:45,120 --> 00:01:45,840 Speaker 2: A sandwich. 37 00:01:45,920 --> 00:01:49,480 Speaker 1: Specifically, we are living in a thin, compressed pancake of 38 00:01:49,560 --> 00:01:53,359 dark matter that is being squeezed between two massive empty voids. 39 00:01:53,760 --> 00:01:57,400 Speaker 2: It is a striking, almost claustrophobic image when you really 40 00:01:57,439 --> 00:01:59,560 think about it, and honestly, it changes the way you 41 00:01:59,599 --> 00:02:02,319 look at the right. It turns out our neighborhood, our 42 00:02:02,439 --> 00:02:05,560 entire galaxy cluster, isn't just a random suburb in space. 43 00:02:06,120 --> 00:02:08,639 It's a structural anomaly. It's a special place. 44 00:02:08,919 --> 00:02:12,439 Speaker 1: Welcome to Thrilling Threads. I'm your host, and today I 45 00:02:12,479 --> 00:02:16,599 am ready to have my perception of reality completely flattened 46 00:02:16,639 --> 00:02:17,879 like a crape. 47 00:02:17,439 --> 00:02:19,199 Speaker 2: And I'm here to help pick up the pieces and 48 00:02:19,319 --> 00:02:22,719 hopefully explain why living in a pancake might solve one 49 00:02:22,719 --> 00:02:24,719 of the biggest crises in modern physics. 50 00:02:25,080 --> 00:02:28,639 Speaker 1: We are unpacking a really fascinating and honestly kind of 51 00:02:29,360 --> 00:02:32,680 kind of troubling new paper today. It suggests that our 52 00:02:32,719 --> 00:02:36,919 place in the universe isn't just random, it's statistically weird, 53 00:02:38,000 --> 00:02:41,400 and it might force us to completely rewrite what we 54 00:02:41,479 --> 00:02:44,479 think we know about the invisible stuff that makes up 55 00:02:44,639 --> 00:02:46,319 well most of the cosmos, that. 56 00:02:46,400 --> 00:02:48,319 Speaker 2: Is the core of it. This isn't just about mapping 57 00:02:48,319 --> 00:02:51,240 where we are. It's about understanding the invisible scaffolding, the 58 00:02:51,360 --> 00:02:53,479 dark matter, the dark matter, the stuff that holds the 59 00:02:53,560 --> 00:02:57,080 universe together, or, as this paper suggests, the invisible scaffolding 60 00:02:57,159 --> 00:02:59,599 that might be oh, it might be crumbling under the 61 00:02:59,599 --> 00:03:00,639 weight of new observation. 62 00:03:00,879 --> 00:03:03,479 Speaker 1: So we have an orc, we have a pancake, and 63 00:03:03,520 --> 00:03:06,719 we have a potential crisis in the standard model of cosmology. 64 00:03:07,120 --> 00:03:09,639 Let's get into the set. Before we get to the sandwich, 65 00:03:09,680 --> 00:03:13,120 we need to talk about the ingredients, or maybe more accurately, 66 00:03:13,159 --> 00:03:14,159 the missing ingredients. 67 00:03:14,520 --> 00:03:17,800 Speaker 2: Right. To understand why this new paper is such a bombshell, 68 00:03:18,039 --> 00:03:20,960 we have to establish the baseline. For decades now, the 69 00:03:20,960 --> 00:03:24,680 dominant theory and cosmology, the gold standard has been the 70 00:03:24,800 --> 00:03:27,319 Lambda CDM model Lambda CDM. 71 00:03:27,800 --> 00:03:30,479 Speaker 1: It sounds like a fraternity for physicists. Can we break 72 00:03:30,479 --> 00:03:32,479 that acronym down quickly for everyone, just so we're all 73 00:03:32,520 --> 00:03:33,280 on the same page. 74 00:03:33,360 --> 00:03:36,159 Speaker 2: Sure, it's essentially the standard model of the Big Bang. 75 00:03:36,960 --> 00:03:39,400 Lambda represents dark energy. 76 00:03:39,199 --> 00:03:41,919 Speaker 1: The mysterious force that is accelerating the expansion of the. 77 00:03:41,960 --> 00:03:45,840 Speaker 2: Universe exactly, that's the pushing out force. And then CDM 78 00:03:45,960 --> 00:03:47,800 stands for cold. 79 00:03:47,560 --> 00:03:49,360 Speaker 1: Dark matter, cold dark matter. 80 00:03:49,560 --> 00:03:52,479 Speaker 2: Yes, the theory posits that the vast majority of matter 81 00:03:52,479 --> 00:03:55,319 in the universe is this slow moving stuff. That's the 82 00:03:55,360 --> 00:03:58,439 cold part, and it's invisible, that's the dark part. We 83 00:03:58,479 --> 00:03:59,960 call it dark matter, and that's. 84 00:03:59,759 --> 00:04:02,439 Speaker 1: The famous eighty percent figure, right or something like that. 85 00:04:02,560 --> 00:04:05,599 Speaker 2: Roughly, Yeah, The idea is that about eighty percent to 86 00:04:05,639 --> 00:04:08,000 eighty five percent of all the matter in the universe 87 00:04:08,080 --> 00:04:12,080 is this invisible substance. It has mass, so it exerts gravity, 88 00:04:12,400 --> 00:04:15,719 and it basically acts as the glue holding galaxies together. 89 00:04:15,840 --> 00:04:17,879 Speaker 1: So without it, galaxies would just fly apart. 90 00:04:18,079 --> 00:04:21,639 Speaker 2: They would if you just look at the visible matter stars, 91 00:04:21,920 --> 00:04:28,759 gas planets, you me this microphone. There isn't enough gravity 92 00:04:28,920 --> 00:04:31,800 to keep a galaxy like the Milky Way from flinging 93 00:04:31,839 --> 00:04:33,319 itself apart as it spins. 94 00:04:33,600 --> 00:04:36,000 Speaker 1: So dark matter is the safety belt at the galaxy. 95 00:04:36,120 --> 00:04:38,800 Speaker 2: It's even more fundamental than that. It's the scaffolding. Okay, 96 00:04:39,199 --> 00:04:41,879 imagine a building where you can only see the dry wall, 97 00:04:42,160 --> 00:04:44,959 but you can't see any of the steel beams. The 98 00:04:45,079 --> 00:04:47,560 dark matter is the steel beams. We assume it's there 99 00:04:47,600 --> 00:04:50,639 because well, because the building is standing up, and we 100 00:04:50,680 --> 00:04:52,720 all know drywall doesn't stand up on its own. 101 00:04:52,920 --> 00:04:56,000 Speaker 1: That is a great analogy. But and here is the 102 00:04:56,000 --> 00:04:57,560 butt that keeps me up at nine, and I know 103 00:04:57,600 --> 00:05:00,360 it bothers a lot of people in your field. We 104 00:05:00,439 --> 00:05:02,319 have never actually seen this deal beams. 105 00:05:02,399 --> 00:05:04,879 Speaker 2: We haven't, not directly, and that is the source of 106 00:05:04,959 --> 00:05:08,040 all the tension. We haven't found decisive evidence that it 107 00:05:08,079 --> 00:05:11,000 is a particle. I mean, we have built these massive detectors, 108 00:05:11,560 --> 00:05:14,439 buried them deep underground, and abandoned minds to shield them 109 00:05:14,439 --> 00:05:15,920 from cosmic radiation, like. 110 00:05:15,879 --> 00:05:19,480 Speaker 1: The lux z Plen experiment, a giant tank of xenon. 111 00:05:19,600 --> 00:05:24,920 Speaker 2: Exactly huge tanks of liquid xenon, just waiting, waiting for 112 00:05:25,000 --> 00:05:27,839 a dark matter particle to bump into one of its nuclei. 113 00:05:28,279 --> 00:05:31,199 We've smashed atoms together at the Large Hadron Collider, hoping 114 00:05:31,199 --> 00:05:35,040 to produce one and nothing. We haven't found a single 115 00:05:35,079 --> 00:05:36,680 particle that fits the description. 116 00:05:37,519 --> 00:05:39,560 Speaker 1: So it's a ghost in the machine. But I mean, 117 00:05:39,560 --> 00:05:41,439 we haven't proven it doesn't exist either. 118 00:05:41,199 --> 00:05:44,560 Speaker 2: Have we No, And that's the problem. We have no 119 00:05:44,680 --> 00:05:48,319 decisive evidence against it being a particle either. The math 120 00:05:48,480 --> 00:05:51,079 just works so well on large scales that we can't 121 00:05:51,160 --> 00:05:55,240 let it go. We are stuck in this scientific limbo, 122 00:05:56,160 --> 00:05:58,240 as the source material for Today puts it. And I 123 00:05:58,279 --> 00:06:00,839 love this quote. It's really infuriating. 124 00:06:01,040 --> 00:06:04,079 Speaker 1: I love that too. It's infuriating. You can feel the 125 00:06:04,160 --> 00:06:07,439 visceral frustration of the physicists in that line, can't you. Absolutely, 126 00:06:07,480 --> 00:06:09,839 it's not just a puzzle anymore. It's an annoyance. It's 127 00:06:09,839 --> 00:06:11,560 like looking for your keys when you know they are 128 00:06:11,560 --> 00:06:13,680 in the house, but you've torn the catch up part 129 00:06:13,720 --> 00:06:15,879 three times and they're just not there. 130 00:06:15,839 --> 00:06:17,720 Speaker 2: And you're starting to wonder if the keys ever existed 131 00:06:17,759 --> 00:06:20,800 in the first place, or if you just you know, hallucinated. 132 00:06:20,160 --> 00:06:23,399 Speaker 1: Them exactly and this is where the drama really starts 133 00:06:23,439 --> 00:06:26,560 to build, because the standard theory of dark matter, the 134 00:06:26,600 --> 00:06:28,560 one we've all been taught in school, the one on 135 00:06:28,600 --> 00:06:31,240 all the posters at the science Museum, is starting to 136 00:06:31,279 --> 00:06:33,759 feel a little bit shaky. 137 00:06:33,920 --> 00:06:35,680 Speaker 2: Shaky is a very polite way to put it. 138 00:06:35,800 --> 00:06:38,800 Speaker 1: The source goes even further. They imply that the standard 139 00:06:38,839 --> 00:06:41,839 theory is starting to feel less like hard science and 140 00:06:41,879 --> 00:06:43,920 more like a creative writing exercise. 141 00:06:44,000 --> 00:06:47,879 Speaker 2: That is a stinging critique, but it captures the mood 142 00:06:47,879 --> 00:06:51,040 in the community perfectly. We are seeing a trend where 143 00:06:51,399 --> 00:06:53,680 to keep the dark matter theory alive in the face 144 00:06:53,680 --> 00:06:56,600 of new data, we have to keep adding new rules. 145 00:06:56,639 --> 00:06:58,600 We have to keep tweaking the story. 146 00:06:58,720 --> 00:07:00,399 Speaker 1: It's like a plot hole in a movie that the 147 00:07:00,399 --> 00:07:03,680 writers try to fix with a really convoluted backstory, and 148 00:07:03,720 --> 00:07:05,360 then that creates another plot hole, so they have to 149 00:07:05,360 --> 00:07:07,519 write a prequel to explain that one precisely. 150 00:07:07,839 --> 00:07:09,920 Speaker 2: And that brings us right back to this new paper, 151 00:07:10,480 --> 00:07:13,040 because if this paper is right, we are sitting in 152 00:07:13,079 --> 00:07:17,000 a very very peculiar structural anomaly that the standard simple 153 00:07:17,040 --> 00:07:20,959 models struggle to explain naturally, not without even more creative writing. 154 00:07:21,199 --> 00:07:24,639 Speaker 1: Okay, let's get into segment one, the shape of our reality. 155 00:07:24,959 --> 00:07:27,199 I want to go back to this pancake because when 156 00:07:27,240 --> 00:07:30,120 I hear pantake, I think breakfast. But we're talking about 157 00:07:30,120 --> 00:07:33,600 a galactic scale here. What exactly is the local sheet? 158 00:07:34,000 --> 00:07:36,519 Speaker 2: So to understand this you have to know about way 159 00:07:36,560 --> 00:07:39,480 way out, way past the Milky Way. Okay, we are 160 00:07:39,519 --> 00:07:42,120 part of a group of galaxies called the local group. 161 00:07:42,240 --> 00:07:45,639 You've got Us, Andromeda a few others, and the local 162 00:07:45,639 --> 00:07:48,160 group is part of a larger structure. 163 00:07:47,839 --> 00:07:49,399 Speaker 1: A supercluster. Is that the right term? 164 00:07:49,560 --> 00:07:53,759 Speaker 2: Essentially, yes, and the paper describes our local environment. The 165 00:07:53,800 --> 00:07:57,160 technical term is the local sheet as a flat, thin 166 00:07:57,360 --> 00:08:02,360 concentration of mass. Imagine a vast, flattened region where all 167 00:08:02,399 --> 00:08:05,399 the galaxies, including the Milky Way, Andromeda, and our neighbors 168 00:08:05,399 --> 00:08:07,959 in the Virgo cluster, are all clustered together. 169 00:08:08,079 --> 00:08:10,519 Speaker 1: Why is flat weird? I mean, the Solar system is flat, right, 170 00:08:10,639 --> 00:08:14,120 the planet's orbit in a disc. Galaxies themselves are flat discs. 171 00:08:14,319 --> 00:08:15,839 Why shouldn't the cluster be flat? 172 00:08:16,279 --> 00:08:19,000 Speaker 2: That's a great question, and it's an important distinction. Solar 173 00:08:19,000 --> 00:08:22,000 systems and galaxies are flat because of angular momentum. 174 00:08:22,079 --> 00:08:22,639 Speaker 1: They're spinning. 175 00:08:22,800 --> 00:08:25,439 Speaker 2: They spin, and that spinning flattens them out like pizza do. 176 00:08:26,319 --> 00:08:29,199 But on the scale of galaxy clusters we are talking 177 00:08:29,879 --> 00:08:33,440 tens of millions of light years across. Gravity usually just 178 00:08:33,480 --> 00:08:37,960 pulls things into filaments or big spherical blob like a spun. 179 00:08:38,120 --> 00:08:39,679 Speaker 1: I've heard it called the cosmic web. 180 00:08:39,840 --> 00:08:42,200 Speaker 2: Exactly. The cosmic web usually looks like a three D 181 00:08:42,240 --> 00:08:46,279 spund or aus spider web. Finding a distinct razor thin 182 00:08:46,480 --> 00:08:52,080 sheet that extends for this enormous distance is well, it's unique. 183 00:08:52,120 --> 00:08:54,840 It implies a very specific type of compression happened. 184 00:08:54,840 --> 00:08:57,240 Speaker 1: Okay, so instead of a big round ball of galaxies 185 00:08:57,360 --> 00:08:59,759 or a scattered cloud, we are living in a cosmic 186 00:08:59,759 --> 00:09:02,039 shaitt a pancake. 187 00:09:01,720 --> 00:09:05,320 Speaker 2: Precisely, and this pancake of dark matter is sandwiched on 188 00:09:05,440 --> 00:09:08,440 either side of this flat sheet. There are two huge, 189 00:09:08,519 --> 00:09:12,639 almost void regions, bubbles of nothingness, almost empty bubbles, is 190 00:09:12,679 --> 00:09:14,600 how the source describes them. One of them is called 191 00:09:14,600 --> 00:09:15,360 the local void. 192 00:09:15,799 --> 00:09:18,240 Speaker 1: The local void that sounds like a dive bar in 193 00:09:18,279 --> 00:09:19,159 a sci fi movie. 194 00:09:19,200 --> 00:09:21,559 Speaker 2: It does, doesn't it. It's a massive region of space 195 00:09:21,639 --> 00:09:24,399 with very very few galaxies. And on the other side 196 00:09:24,399 --> 00:09:27,879 you have another underdense region, often associated with something called 197 00:09:27,879 --> 00:09:29,080 the North Polar spur. 198 00:09:29,440 --> 00:09:33,600 Speaker 1: So let me see if I have this right, you 199 00:09:33,639 --> 00:09:36,519 have this high density wall or sheet in the mirror 200 00:09:36,639 --> 00:09:40,320 axis and then just deep emptiness on both sides. 201 00:09:40,399 --> 00:09:42,039 Speaker 2: That's the picture that is. 202 00:09:42,000 --> 00:09:44,120 Speaker 1: Such a weird mental image. It's like we are living 203 00:09:44,120 --> 00:09:49,039 on a partition wall between two gigantic empty rooms, or 204 00:09:49,080 --> 00:09:52,080 like the cream filling in an oreo if the cookies 205 00:09:52,080 --> 00:09:53,039 were made of nothingness. 206 00:09:53,399 --> 00:09:56,360 Speaker 2: That is a great analogy. And the paper suggests that 207 00:09:56,559 --> 00:09:59,440 dark matter, if it exists in the way Lambda CDM 208 00:09:59,440 --> 00:10:03,759 says it does, must be strongly concentrated along this mirror axis. 209 00:10:04,039 --> 00:10:07,039 It squeezed into the pancake, leaving the bubbles empty, and this. 210 00:10:06,960 --> 00:10:09,080 Speaker 1: Is where the orc comes in. The source mentioned that 211 00:10:09,080 --> 00:10:11,480 if you look at the visualization of this structure, the 212 00:10:11,519 --> 00:10:13,799 pancake and the voids, it looks like an orc. I'm 213 00:10:13,840 --> 00:10:16,320 still trying to picture it. Are the voids the eyes. 214 00:10:16,480 --> 00:10:18,799 Speaker 2: It's a bit of a roar shot test for cosmologists, 215 00:10:18,919 --> 00:10:21,080 you know. But yes, if you look at the density 216 00:10:21,080 --> 00:10:23,919 maps from the simulation, the voids act as these large 217 00:10:23,919 --> 00:10:26,159 hollowed out eye sockets. They are dark and empty. 218 00:10:26,240 --> 00:10:27,840 Speaker 1: Okay, I can see that, and the local. 219 00:10:27,600 --> 00:10:30,480 Speaker 2: Sheet, the dense region where we live forms the bridge 220 00:10:30,519 --> 00:10:33,080 of the nose, the heavy brow ridge, and maybe the mouth. 221 00:10:33,440 --> 00:10:37,200 Speaker 1: It's funny, but it's also kind of haunting. The universe 222 00:10:37,240 --> 00:10:40,480 has a face, and it's not a friendly face. It's 223 00:10:40,519 --> 00:10:40,879 an orc. 224 00:10:41,240 --> 00:10:44,000 Speaker 2: It definitely has character. But the point the author was 225 00:10:44,000 --> 00:10:48,000 making is playful but serious. The universe isn't just a 226 00:10:48,120 --> 00:10:52,320 uniform fog. It has structure, it has distinct features, and 227 00:10:52,360 --> 00:10:54,320 we happen to live in one of the most distinct 228 00:10:54,360 --> 00:10:55,279 features of all. 229 00:10:55,679 --> 00:10:58,639 Speaker 1: And when we say we are in the pancake, we 230 00:10:58,679 --> 00:11:02,039 need to clarify we. I'm assuming we don't just mean 231 00:11:02,080 --> 00:11:03,879 Earth or the Solar System. 232 00:11:03,919 --> 00:11:06,159 Speaker 2: No, no, not just Earth, not just the Solar System, not 233 00:11:06,200 --> 00:11:08,639 even just the Milky Way galaxy. When the paper says we, 234 00:11:09,279 --> 00:11:12,360 it refers to the entire cluster of galaxies. We are 235 00:11:12,360 --> 00:11:14,639 surrounded by our whole cosmic neighborhood. 236 00:11:14,720 --> 00:11:16,039 Speaker 1: That is a massive neighborhood. 237 00:11:16,080 --> 00:11:18,840 Speaker 2: It is the scale is tens of millions of light years, 238 00:11:19,159 --> 00:11:21,960 and yet on that enormous scale, it's flat. It's a sheet. 239 00:11:22,279 --> 00:11:24,519 Speaker 1: It makes you feel kind of special, doesn't it. I mean, 240 00:11:24,600 --> 00:11:27,000 we aren't just floating in some random soup. We are 241 00:11:27,000 --> 00:11:28,440 in the pancake of destiny. 242 00:11:28,559 --> 00:11:31,639 Speaker 2: We'll hold that thought on destiny because usually in cosmology, 243 00:11:31,720 --> 00:11:33,919 if you find yourself in a special place, that is 244 00:11:33,960 --> 00:11:35,080 a massive red flag. 245 00:11:35,200 --> 00:11:37,639 Speaker 1: Why everyone wants to be special. My mom told me 246 00:11:37,639 --> 00:11:38,240 I was special. 247 00:11:38,440 --> 00:11:41,639 Speaker 2: Your mom is definitely right. But in physics, special is 248 00:11:41,639 --> 00:11:44,840 a problem. We rely on something called Copernican. 249 00:11:44,320 --> 00:11:47,080 Speaker 1: Principle, the idea that we are not the center of 250 00:11:47,080 --> 00:11:48,080 the universe. 251 00:11:47,759 --> 00:11:50,960 Speaker 2: Right, we are not in a privileged position. The universe 252 00:11:50,960 --> 00:11:53,440 should look roughly the same no matter where you are standing. 253 00:11:53,519 --> 00:11:55,759 That's a core assumption called homogeneity. 254 00:11:56,480 --> 00:11:59,039 Speaker 1: So if the universe is supposed to be the same everywhere, 255 00:11:59,279 --> 00:12:03,240 finding ourselves in this highly specific odd structure that looks 256 00:12:03,279 --> 00:12:06,200 like an orc, well, it raises some mybrows. 257 00:12:06,279 --> 00:12:09,320 Speaker 2: Exactly. It suggests that maybe our local patch of the 258 00:12:09,360 --> 00:12:13,320 universe is violating the standard rules, or perhaps more disturbingly, 259 00:12:13,360 --> 00:12:16,600 that the standard rules don't actually predict what we see around. 260 00:12:16,320 --> 00:12:18,799 Speaker 1: Us, which is a perfect segue. Okay, so we are 261 00:12:18,799 --> 00:12:21,360 in an orc shaped dark matter sandwich. That's the one. 262 00:12:21,440 --> 00:12:23,519 Now I want to get into the why this is 263 00:12:23,559 --> 00:12:27,039 a problem. This brings us to segment two, the trouble 264 00:12:27,039 --> 00:12:30,360 with dark matter. You mentioned earlier that the theory is 265 00:12:30,399 --> 00:12:35,039 becoming a creative writing exercise, let's uttack that what exactly 266 00:12:35,080 --> 00:12:36,360 is going wrong with the theory. 267 00:12:36,600 --> 00:12:38,399 Speaker 2: This is where we have to look at the track 268 00:12:38,440 --> 00:12:41,000 record of the dark matter theory over the last decade 269 00:12:41,080 --> 00:12:44,399 or so. The issue is that the observations what we 270 00:12:44,519 --> 00:12:47,759 actually see through a telescopes keep contradicting what the dark 271 00:12:47,759 --> 00:12:49,679 matter computer models predict. 272 00:12:49,440 --> 00:12:51,840 Speaker 1: And every time that happens, the theorists have to go 273 00:12:51,960 --> 00:12:54,440 back and fix the model. 274 00:12:54,600 --> 00:12:58,279 Speaker 2: Right, and in science, you want a theory that predicts things, 275 00:12:58,399 --> 00:13:00,759 not a theory that you have to constant patch up 276 00:13:00,799 --> 00:13:03,360 after the fact. If you have to keep adding what 277 00:13:03,399 --> 00:13:07,480 we call epicycles, extra little distinct rules to make it work. 278 00:13:07,759 --> 00:13:10,559 Eventually you have to ask if the core theory is flawed. 279 00:13:10,919 --> 00:13:13,960 Speaker 1: Okay, give me a concrete example. What's the first big anomaly. 280 00:13:14,240 --> 00:13:17,200 Speaker 2: Let's talk about galactic cores. This is often called the 281 00:13:17,279 --> 00:13:18,720 cusp core problem. 282 00:13:18,759 --> 00:13:22,519 Speaker 1: The cusp core problem sounds pointy. Lay it on me 283 00:13:22,519 --> 00:13:23,720 in plain English. 284 00:13:23,559 --> 00:13:26,559 Speaker 2: Standard cold dark matter theory is very very clear on 285 00:13:26,600 --> 00:13:29,799 how gravity works. It predicts that dark matter should clump 286 00:13:29,879 --> 00:13:32,639 effectively in the center of galaxies. It should get very 287 00:13:32,720 --> 00:13:35,240 very dense in the middle. We call this a cusp. 288 00:13:35,480 --> 00:13:37,799 A cusp think of it like a sharp mountain peak 289 00:13:37,840 --> 00:13:38,399 of density. 290 00:13:38,639 --> 00:13:41,480 Speaker 1: So if we could see dark matter, there should be 291 00:13:41,559 --> 00:13:45,799 a big, bright, well invitible ball of heavy stuff right 292 00:13:45,840 --> 00:13:48,000 in the middle of the Milky Way, a sharp. 293 00:13:47,759 --> 00:13:51,360 Speaker 2: Spike, correct a very sharp spike in density. But when 294 00:13:51,399 --> 00:13:54,799 we observe the way stars and gas move near the 295 00:13:54,840 --> 00:13:58,080 centers of galaxies, we don't see evidence for that sharp spike. 296 00:13:58,200 --> 00:13:59,240 Speaker 1: What do we see instead? 297 00:13:59,440 --> 00:14:03,279 Speaker 2: The observation suggest the core is much smoother. It's flat. 298 00:14:03,480 --> 00:14:06,639 It's a core, not a cusp. Imagine a flat plateau 299 00:14:06,720 --> 00:14:09,279 instead of a mountain peak. The dark matter seems to 300 00:14:09,320 --> 00:14:11,919 be spread out evenly, not clumped up in the middle. 301 00:14:12,120 --> 00:14:14,519 Speaker 1: So the map doesn't match the territory. Yeah, the theory 302 00:14:14,559 --> 00:14:17,759 says mountain, and the telescope says plateau exactly. 303 00:14:17,879 --> 00:14:20,159 Speaker 2: So what do the theorists do. They don't throw out 304 00:14:20,159 --> 00:14:23,120 the theory, of course not. They tweak the model. They 305 00:14:23,159 --> 00:14:25,559 introduce what they call baryonic feedback. 306 00:14:25,679 --> 00:14:28,519 Speaker 1: Buryonic feedback. That sounds suspiciously technical. 307 00:14:28,600 --> 00:14:32,000 Speaker 2: It's a fancy way of saying supernova's. They say, well, 308 00:14:32,000 --> 00:14:34,879 maybe supernova explosions in the center of the galaxy push 309 00:14:34,919 --> 00:14:38,240 the dark matter out, or maybe there's some complex feedback 310 00:14:38,320 --> 00:14:41,919 mechanism between gas and dark matter that smoothed out the bump. 311 00:14:42,039 --> 00:14:44,360 Speaker 1: Is that plausible? I mean, could that actually. 312 00:14:44,039 --> 00:14:48,919 Speaker 2: Happen physically possible? Supernovas are incredibly powerful, but you have 313 00:14:48,960 --> 00:14:51,000 to fine tune the math just right to make it 314 00:14:51,039 --> 00:14:53,960 happen in every galaxy we see. As the source says, 315 00:14:54,120 --> 00:14:56,960 one can make that work, but it feels forced. 316 00:14:57,240 --> 00:14:59,639 Speaker 1: One can make that work. Yeah, it sounds like when 317 00:14:59,639 --> 00:15:01,399 I'm trying to to fix a waterly table and I 318 00:15:01,440 --> 00:15:04,240 just keep shoving folded paper under the leg until it 319 00:15:04,240 --> 00:15:08,360 stops moving. It works, but it's not exactly elegant engineering. 320 00:15:08,559 --> 00:15:12,720 Speaker 2: That is a distressingly accurate analogy. You're patching the theory 321 00:15:13,120 --> 00:15:16,000 and it happens again with satellite galaxies. Okay, this is 322 00:15:16,039 --> 00:15:17,519 the missing satellites problem. 323 00:15:17,559 --> 00:15:19,600 Speaker 1: I've heard of this. This is about the little, tiny 324 00:15:19,600 --> 00:15:21,840 galaxies that orbit big ones like ours. 325 00:15:21,960 --> 00:15:26,440 Speaker 2: Yes, the dark matter simulations predict that large galaxies like 326 00:15:26,519 --> 00:15:30,759 our Milky Way should be surrounded by hundreds, potentially thousands, 327 00:15:30,759 --> 00:15:33,639 of smaller clumps of dark matter, each one hosting a 328 00:15:33,679 --> 00:15:35,200 tiny dwarf galaxy like. 329 00:15:35,240 --> 00:15:36,759 Speaker 1: A swarm of bees around a hive. 330 00:15:37,000 --> 00:15:39,720 Speaker 2: Exactly because the dark matter is messy, right, it should 331 00:15:39,720 --> 00:15:42,879 break off into little chunks. Gravity is fractal in these simulations. 332 00:15:42,879 --> 00:15:46,200 It makes big clumps and little clumps. The simulation says, look. 333 00:15:46,039 --> 00:15:47,720 Speaker 1: For the swarm, and whether we see a swarm. 334 00:15:47,919 --> 00:15:51,120 Speaker 2: We see a few. We have the Magellanic clouds, which 335 00:15:51,120 --> 00:15:54,200 are beautiful, and we've found a handful of other ultra 336 00:15:54,320 --> 00:15:58,960 faint dwarfs. But we don't see hundreds. We see vastly, 337 00:15:59,120 --> 00:16:00,799 vastly fewer. And the theory. 338 00:16:00,559 --> 00:16:03,679 Speaker 1: Predicts so the swarm is missing. Where did they go? 339 00:16:04,000 --> 00:16:07,480 Speaker 2: That's the multi billion dollar question? So how do they 340 00:16:07,480 --> 00:16:08,200 make that work? 341 00:16:09,080 --> 00:16:11,840 Speaker 1: Let me guess they adjust the model again. 342 00:16:11,600 --> 00:16:13,600 Speaker 2: They adjust the model. They say, well, maybe the small 343 00:16:13,600 --> 00:16:16,480 clumps of dark matter exist, but they just didn't manage 344 00:16:16,480 --> 00:16:19,600 to attract enough gas to form stars. So the clumps 345 00:16:19,639 --> 00:16:23,080 are there, but they are invisible. They are dark galaxies. 346 00:16:23,440 --> 00:16:26,519 Speaker 1: That feels incredibly convenient. The invisible stuff is there, it's 347 00:16:26,600 --> 00:16:28,799 just doubly invisible now because it didn't light up. 348 00:16:28,960 --> 00:16:31,799 Speaker 2: It protects the theory from being falsified. If you can 349 00:16:31,840 --> 00:16:34,919 always claim the missing evidence is just too faint to see, 350 00:16:34,960 --> 00:16:36,480 you can never really be proven wrong. 351 00:16:36,559 --> 00:16:38,519 Speaker 1: You see the pattern, one can make that work. 352 00:16:38,559 --> 00:16:40,360 Speaker 2: And then there's the big one. The new kid on 353 00:16:40,399 --> 00:16:43,279 the block, A not only number three courtesy of the 354 00:16:43,360 --> 00:16:44,799 James Webb Space Telescope. 355 00:16:44,919 --> 00:16:48,200 Speaker 1: The Early Universe. I remember the headlines when JWST started 356 00:16:48,200 --> 00:16:50,720 sending back those first pictures. People were freaking out. 357 00:16:50,919 --> 00:16:53,720 Speaker 2: They were right to freak out, because under the standard 358 00:16:53,840 --> 00:16:57,840 dark matter model, galaxies build up slowly. It's a bottom 359 00:16:57,960 --> 00:17:01,279 up process, right. Gravity takes time to pull things together. 360 00:17:01,600 --> 00:17:04,680 You start small and messy, and over billions of years 361 00:17:04,720 --> 00:17:07,319 you get big, structured galaxies, slow and. 362 00:17:07,279 --> 00:17:09,599 Speaker 1: Stead He wins the race. You don't get a skyscraper 363 00:17:09,799 --> 00:17:11,400 five minutes after you break around. 364 00:17:11,640 --> 00:17:15,279 Speaker 2: That was the prediction. But JWST looked back at the 365 00:17:15,559 --> 00:17:19,519 very early universe. We're talking red shifts of ten or eleven, 366 00:17:19,599 --> 00:17:23,079 almost right after the Big Bang cosmologically speaking, and what 367 00:17:23,160 --> 00:17:23,720 did it find? 368 00:17:24,240 --> 00:17:26,640 Speaker 1: Big galaxies, huge fully. 369 00:17:26,279 --> 00:17:30,240 Speaker 2: Formed, bright galaxies, some of them massive enough to rival 370 00:17:30,240 --> 00:17:33,079 our own Milky Way, but existing at a time when 371 00:17:33,160 --> 00:17:35,039 the universe was just in its infancy. 372 00:17:35,200 --> 00:17:37,839 Speaker 1: It's like walking into a nursery and finding a newborn 373 00:17:37,880 --> 00:17:40,319 baby who was already six feet tall, wearing a suit 374 00:17:40,519 --> 00:17:41,799 and trading stocks. 375 00:17:41,480 --> 00:17:45,319 Speaker 2: A perfect analogy. It completely defies the developmental timeline we 376 00:17:45,400 --> 00:17:48,319 expected the universe shouldn't have been able to organize itself 377 00:17:48,319 --> 00:17:50,640 that quickly if it was relying on the slow, steady 378 00:17:50,640 --> 00:17:52,680 trickle of cold dark matter gravity. 379 00:17:52,759 --> 00:17:55,079 Speaker 1: And what was the response? Did they scrap the theory? 380 00:17:55,119 --> 00:17:57,559 Speaker 2: Oh? They said, well, maybe star formation was just more 381 00:17:57,559 --> 00:18:00,839 efficient back then, or maybe our calibration was off, maybe 382 00:18:00,880 --> 00:18:04,440 the dust obscures the real mass. They find a way 383 00:18:04,519 --> 00:18:06,880 to keep the dark matter framework, but they have to 384 00:18:06,920 --> 00:18:09,559 bend it into a pretzel to make it fit, and. 385 00:18:09,480 --> 00:18:12,200 Speaker 1: That's why the source calls it a creative writing exercise. 386 00:18:12,480 --> 00:18:16,359 Speaker 2: Yes, the critique is this, at what point does a 387 00:18:16,400 --> 00:18:21,359 theory stop being predictive and start being merely reactive? If 388 00:18:21,359 --> 00:18:25,079 you have to modify the story after every single new discovery, 389 00:18:25,119 --> 00:18:28,359 are you actually explaining the universe or are you just 390 00:18:28,400 --> 00:18:29,799 describing it after the fact. 391 00:18:29,839 --> 00:18:32,200 Speaker 1: That is a savage burn on the physics community. But 392 00:18:32,319 --> 00:18:34,480 I mean, given the list you just gave, it feels 393 00:18:34,559 --> 00:18:35,359 kind of justified. 394 00:18:35,480 --> 00:18:37,880 Speaker 2: It is a valid scientific concern. Science is supposed to 395 00:18:37,920 --> 00:18:40,759 be about falsifiability. You have to be able to be 396 00:18:40,799 --> 00:18:43,480 proven wrong. If your theory acts like a chameleon and 397 00:18:43,559 --> 00:18:46,359 changes color to match whatever background you put it against, 398 00:18:46,640 --> 00:18:48,839 it's not a very useful theory anymore. 399 00:18:48,440 --> 00:18:51,079 Speaker 1: Which brings us back to the pancake, because this new 400 00:18:51,119 --> 00:18:53,400 paper is essentially saying, Okay, if you want to keep 401 00:18:53,400 --> 00:18:56,119 the standard model, if you want to keep LAMB to CDM, 402 00:18:56,599 --> 00:18:59,599 here is the extremely weird shape you have to accept 403 00:18:59,599 --> 00:19:00,000 we live in. 404 00:19:00,480 --> 00:19:02,839 Speaker 2: Right. They are testing the limits of the model by 405 00:19:02,839 --> 00:19:05,319 looking at our local address in the cosmos. 406 00:19:05,440 --> 00:19:08,759 Speaker 1: Okay, let's move to segment three. How did they find it? 407 00:19:09,279 --> 00:19:12,440 Because we've established pretty clearly that dark matter is invisible, 408 00:19:13,039 --> 00:19:16,079 So how do these researchers know we're in a pancake 409 00:19:16,200 --> 00:19:20,559 between two voids? Did they just look at the stars 410 00:19:20,599 --> 00:19:21,079 and guess? 411 00:19:21,400 --> 00:19:24,480 Speaker 2: No guessing involved. They used a very sophisticated tool called 412 00:19:24,519 --> 00:19:30,160 structure simulation models. Specifically, they used a technique called constrained realizations. 413 00:19:30,279 --> 00:19:33,559 Speaker 1: Okay, break that down for me. Constrained realizations. That sounds 414 00:19:33,599 --> 00:19:36,720 like a therapy technique. I had a constrained realization about 415 00:19:36,720 --> 00:19:37,799 my childhood. 416 00:19:37,319 --> 00:19:40,240 Speaker 2: Today, Doc, It does, doesn't it? But in physics it 417 00:19:40,319 --> 00:19:43,880 means running a simulation that isn't random. Oka. Usually when 418 00:19:43,920 --> 00:19:46,680 cosmologists simulate the universe, they just throw in some random 419 00:19:46,680 --> 00:19:49,000 initial conditions, press play and see what kind of universe 420 00:19:49,000 --> 00:19:50,640 pops out. They get a generic universe. 421 00:19:50,640 --> 00:19:53,440 Speaker 1: A generic universe like buying a universe starter pack from 422 00:19:53,480 --> 00:19:54,839 a store exactly. 423 00:19:55,160 --> 00:19:58,599 Speaker 2: But that doesn't help us understand our specific neighborhood. So 424 00:19:58,960 --> 00:20:02,359 these researchers did something different. They started with the standard 425 00:20:02,440 --> 00:20:06,319 cosmological model Lambda CDM, but they added. 426 00:20:06,000 --> 00:20:08,279 Speaker 1: Constraints, constraints, what kind of constraints. 427 00:20:08,319 --> 00:20:12,440 Speaker 2: They forced the simulation to match the actual position of 428 00:20:12,480 --> 00:20:16,079 the galaxies we see in the sky today. They basically said, okay, computer, 429 00:20:16,480 --> 00:20:19,440 simulate a universe from the Big Bang forward. But at 430 00:20:19,440 --> 00:20:22,359 the end of the simulation, the Milky Way must be here, 431 00:20:22,720 --> 00:20:26,119 Andromeda must be over there, and the Virgo cluster must 432 00:20:26,200 --> 00:20:27,559 be in that exact spot. 433 00:20:27,960 --> 00:20:31,240 Speaker 1: So they rigged the game. They started with the answer. 434 00:20:31,000 --> 00:20:33,759 Speaker 2: In a way, Yes, they rigged it to match reality. 435 00:20:33,799 --> 00:20:36,680 They reverse engineered the Big Bang. They asked the question, 436 00:20:37,319 --> 00:20:40,119 what must the initial conditions have been, and more importantly, 437 00:20:40,440 --> 00:20:43,519 where must the unseen dark matter be today to produce 438 00:20:43,640 --> 00:20:46,880 this specific arrangement of visible galaxies that we observe. 439 00:20:47,119 --> 00:20:49,480 Speaker 1: Ah, I see so because the galaxies are just the 440 00:20:49,519 --> 00:20:51,240 tip of the iceberg. They're like the lights on the 441 00:20:51,319 --> 00:20:53,799 Christmas tree. If you know exactly where all the lights are, 442 00:20:54,079 --> 00:20:56,359 you can figure out the shape of the invisible branches 443 00:20:56,400 --> 00:20:57,960 holding them up exactly. 444 00:20:58,079 --> 00:21:01,799 Speaker 2: That is the perfect metaphoras. Galaxies are the tracers. They 445 00:21:01,920 --> 00:21:05,440 follow the gravitational pull of the dark matter. So if 446 00:21:05,480 --> 00:21:08,240 you see a sheet of galaxies, the computer deduces that 447 00:21:08,279 --> 00:21:10,599 there must be a sheet of dark matter holding them there. 448 00:21:11,160 --> 00:21:12,720 Speaker 1: And they didn't just run this once. 449 00:21:12,640 --> 00:21:15,480 Speaker 2: Oh no, they ran it thousands of times. They created 450 00:21:15,640 --> 00:21:19,880 thousands of potential universes that all ended up looking exactly 451 00:21:20,039 --> 00:21:22,480 like our local neighborhood in terms of the visible matter. 452 00:21:22,559 --> 00:21:24,319 Speaker 1: And what was the common denominator? What did they all 453 00:21:24,359 --> 00:21:24,960 have in common? 454 00:21:25,359 --> 00:21:29,319 Speaker 2: In every single simulation that matched our visible reality, the 455 00:21:29,440 --> 00:21:32,680 underlying dark matter structure was the same. It was that 456 00:21:32,839 --> 00:21:37,440 specific pancake shape with the two massive voids on either side. 457 00:21:37,559 --> 00:21:41,480 Speaker 1: WHOA. So they didn't just see the pancake. They deduced 458 00:21:41,480 --> 00:21:44,279 that the pancake must be there for our reality to 459 00:21:44,359 --> 00:21:46,039 make sense under the current rules. 460 00:21:46,200 --> 00:21:48,519 Speaker 2: Exactly. There was no other way to get the visible 461 00:21:48,519 --> 00:21:52,480 result without that specific invisible structure To explain why our 462 00:21:52,480 --> 00:21:54,880 galaxies are arranged the way they are. The dark matter 463 00:21:54,920 --> 00:21:58,759 has to be squeezed into this thin sheet between empty bubbles. 464 00:21:58,640 --> 00:22:00,880 Speaker 1: So it's not just a pretty pick or a funny 465 00:22:01,000 --> 00:22:04,440 orc face. It's a mathematical necessity of the LAMB to 466 00:22:04,519 --> 00:22:07,799 CDM model when you apply it to our specific location. 467 00:22:08,079 --> 00:22:11,039 Speaker 2: Correct. If the standard model is true, then the orc 468 00:22:11,200 --> 00:22:11,759 is real. 469 00:22:12,480 --> 00:22:15,880 Speaker 1: That's incredibly cool and also incredibly weird, which leads us 470 00:22:15,920 --> 00:22:20,440 to segment four, the odds and the significance. Is this normal? 471 00:22:20,880 --> 00:22:24,480 Are their cosmic pancakes everywhere? Or are we the odd 472 00:22:24,480 --> 00:22:25,000 ones out? 473 00:22:25,200 --> 00:22:28,039 Speaker 2: That is the big question. How rare is a cosmic work? 474 00:22:28,240 --> 00:22:31,279 Speaker 1: I'm guessing pretty rare. I mean orcs in fantasy usually 475 00:22:31,319 --> 00:22:35,279 travel in hordes, but maybe cosmic orcs are solitary creatures. 476 00:22:35,359 --> 00:22:37,559 Speaker 2: The paper tries to quantify this. They looked at how 477 00:22:37,599 --> 00:22:41,559 often structures like our local sheet and these specific voids 478 00:22:41,640 --> 00:22:45,799 appear in those generic random universe simulations we talked about earlier. 479 00:22:45,920 --> 00:22:48,119 Speaker 1: Okay, lay the stance on me. How special are we? 480 00:22:48,319 --> 00:22:50,839 Speaker 2: Earlier estimates and these are from studies looking at similar 481 00:22:50,880 --> 00:22:53,759 structures put the probability of finding ourselves in such a 482 00:22:53,759 --> 00:22:56,559 spot at somewhere between two point five and three point 483 00:22:56,559 --> 00:22:57,400 three sigma. 484 00:22:57,799 --> 00:23:00,680 Speaker 1: Okay, speak English, professor, what is this sigma? I know 485 00:23:00,680 --> 00:23:02,359 it's a Greek letter, but what does it mean in 486 00:23:02,400 --> 00:23:03,279 this context? 487 00:23:03,680 --> 00:23:07,039 Speaker 2: Sigma is a measure of statistical significance. It tells you 488 00:23:07,119 --> 00:23:09,960 how far away a result is from the average from 489 00:23:10,000 --> 00:23:13,799 what's normal. In this context, one sigma is like flipping 490 00:23:13,839 --> 00:23:15,160 a coin and getting heads. 491 00:23:15,160 --> 00:23:16,519 Speaker 1: Totally normal happens all the. 492 00:23:16,440 --> 00:23:20,640 Speaker 2: Time, exactly. Five sigma is the gold standard in particle physics. 493 00:23:20,680 --> 00:23:24,039 For a discovery that's winning the lottery, it's basically considered proof. 494 00:23:24,319 --> 00:23:27,000 Speaker 1: And two point five to three point three sigma where 495 00:23:27,039 --> 00:23:27,640 does that land? 496 00:23:28,039 --> 00:23:30,599 Speaker 2: That translates roughly to a one in one hundred to 497 00:23:30,640 --> 00:23:32,119 a one in one thousand chance. 498 00:23:32,319 --> 00:23:34,440 Speaker 1: So if I have a bag of a thousand universes, 499 00:23:34,640 --> 00:23:37,160 only one of them has us living in this specific 500 00:23:37,319 --> 00:23:38,079 orc sandwich. 501 00:23:38,359 --> 00:23:40,400 Speaker 2: Roughly, Yes, that's the idea. 502 00:23:40,519 --> 00:23:43,519 Speaker 1: That feels rare, but it's not impossible. It's not one in. 503 00:23:43,480 --> 00:23:47,119 Speaker 2: A billion exactly. It's what we call statistically significant but 504 00:23:47,200 --> 00:23:51,359 not impossible. It's in that uncomfortable middle ground. It's just 505 00:23:51,559 --> 00:23:53,519 rare enough to make you wonder if something else is 506 00:23:53,559 --> 00:23:56,279 going on, but not rare enough to completely disprove the 507 00:23:56,279 --> 00:23:57,119 theory on its own. 508 00:23:57,200 --> 00:23:58,920 Speaker 1: It's like winning a raffle at a school for that 509 00:23:58,920 --> 00:24:02,160 you didn't even know you entered. It happens, but you're 510 00:24:02,200 --> 00:24:03,000 pretty surprised. 511 00:24:03,119 --> 00:24:06,200 Speaker 2: Yes, and this brings us to the bullshit meter. 512 00:24:06,680 --> 00:24:09,160 Speaker 1: I love that the source used a bullshit meter. We 513 00:24:09,240 --> 00:24:11,680 need more of those in science. So what was the 514 00:24:11,720 --> 00:24:12,759 score for this paper? 515 00:24:13,440 --> 00:24:14,599 Speaker 2: She gave it a one out of ten? 516 00:24:14,920 --> 00:24:16,599 Speaker 1: Wait, one is low rate or is one high? 517 00:24:16,759 --> 00:24:20,079 Speaker 2: One is very low bullshit? A ten would be total nonsense. 518 00:24:20,119 --> 00:24:22,359 A one means this is solid science. 519 00:24:23,000 --> 00:24:26,119 Speaker 1: Okay. So despite the weird ORC imagery and the strange result, 520 00:24:26,480 --> 00:24:28,440 the methodology behind it is sound. 521 00:24:29,079 --> 00:24:31,880 Speaker 2: It is, but she noted a limitation, which is why 522 00:24:31,920 --> 00:24:34,079 she gave it a one and not a perfect zero. 523 00:24:34,680 --> 00:24:38,720 She can't personally judge the computer simulations. These codes are 524 00:24:38,759 --> 00:24:42,119 incredibly complex, written by teams over years. You have to 525 00:24:42,160 --> 00:24:44,920 trust that the researcher set up the simulation correctly. 526 00:24:45,039 --> 00:24:47,880 Speaker 1: Trust but verify the old motto exactly. 527 00:24:48,160 --> 00:24:51,160 Speaker 2: And she had one other minor annoyance. Oh, the paper 528 00:24:51,279 --> 00:24:55,240 didn't calculate the exact probability for their specific new model. 529 00:24:55,599 --> 00:24:58,440 They relied on those earlier two point five to three 530 00:24:58,519 --> 00:25:01,640 point three sigma estimates from previous studies. She wanted them 531 00:25:01,680 --> 00:25:04,279 to run the numbers fresh for this particular. 532 00:25:03,880 --> 00:25:05,839 Speaker 1: ORC, so we know it's rare, but we don't know 533 00:25:05,880 --> 00:25:09,920 exactly how rare this specific pancake orc situation is correct. 534 00:25:10,160 --> 00:25:12,720 Speaker 2: Hopefully another team will run the numbers soon and give 535 00:25:12,799 --> 00:25:17,279 us a precise figure. But the qualitative result stands we 536 00:25:17,359 --> 00:25:19,839 live in a rare squeezed environment. 537 00:25:20,079 --> 00:25:23,079 Speaker 1: So let's get to segment five, the bigger picture, the 538 00:25:23,119 --> 00:25:26,279 so what question? Why does it matter that I live 539 00:25:26,319 --> 00:25:29,200 in a pancake? I mean, my rent is still the same, 540 00:25:29,279 --> 00:25:32,160 my coffee still tastes the same this morning. Why should 541 00:25:32,200 --> 00:25:34,240 the average listener care about the local sheet? 542 00:25:34,480 --> 00:25:37,039 Speaker 2: It matters because it connects right back to that creative 543 00:25:37,079 --> 00:25:40,440 writing problem we discussed. The more we try to fit 544 00:25:40,480 --> 00:25:44,440 our observations to the standard dark matter model, the weirder 545 00:25:44,480 --> 00:25:46,759 and more special our local environment appears to be. 546 00:25:47,000 --> 00:25:50,240 Speaker 1: It's imagine you have a suit that doesn't fit. You 547 00:25:50,279 --> 00:25:52,000 can tailor it, you can tuck it, you can pin 548 00:25:52,079 --> 00:25:53,960 it here and there, but eventually you look in the 549 00:25:54,000 --> 00:25:57,079 mirror and you just look ridiculous. The proportions are all wrong, And. 550 00:25:57,079 --> 00:25:59,480 Speaker 2: At that point you have to ask yourself a fundamental question, 551 00:25:59,720 --> 00:26:02,160 is my body weird? Or is the suit just the 552 00:26:02,160 --> 00:26:02,799 wrong size? 553 00:26:02,920 --> 00:26:04,599 Speaker 1: Or maybe it's the wrong suit entirely. 554 00:26:04,759 --> 00:26:07,000 Speaker 2: That is the philosophical point at the heart of this 555 00:26:07,319 --> 00:26:10,319 is the universe naturally weird and we just happen to 556 00:26:10,400 --> 00:26:13,200 land in a one in one thousand spot by sheer luck. 557 00:26:13,839 --> 00:26:17,440 Or is our theory of dark matter wrong? The source 558 00:26:17,480 --> 00:26:19,640 suggests that we might be missing something. 559 00:26:19,400 --> 00:26:22,920 Speaker 1: Big, something big, like maybe dark matter isn't a particle 560 00:26:22,920 --> 00:26:23,319 at all. 561 00:26:23,559 --> 00:26:27,839 Speaker 2: That is the leading alternative. There are theories like MOND, 562 00:26:28,079 --> 00:26:31,720 which stands for modified Newtonian dynamics, that suggest we don't 563 00:26:31,759 --> 00:26:34,920 need invisible matter, we just need to tweak our understanding 564 00:26:34,920 --> 00:26:36,200 of gravity itself. 565 00:26:36,440 --> 00:26:39,480 Speaker 1: So maybe gravity just works differently on really big scales, 566 00:26:39,559 --> 00:26:42,720 like how boiling water behaves differently than a single water 567 00:26:42,799 --> 00:26:44,039 molecule exactly. 568 00:26:44,079 --> 00:26:45,880 Speaker 2: And if you change the laws of gravity, maybe this 569 00:26:46,000 --> 00:26:49,319 pancake structure isn't an anomaly anymore. Maybe it's exactly what 570 00:26:49,359 --> 00:26:50,400 you'd expect to see. 571 00:26:50,599 --> 00:26:53,319 Speaker 1: Well, that would certainly solve the creative writing problem. You 572 00:26:53,359 --> 00:26:57,440 wouldn't need to invent invisible galaxies or use supernovas to 573 00:26:57,519 --> 00:26:59,559 push matter around to explain things. 574 00:27:00,519 --> 00:27:03,039 Speaker 2: But mon D has its own set of problems. It's 575 00:27:03,039 --> 00:27:05,960 not a perfect fix either. It really struggles to explain 576 00:27:06,000 --> 00:27:10,160 the cosmic microwave background radiation, for instance, But the tension 577 00:27:10,200 --> 00:27:13,920 between these ideas is leading us somewhere new. And you 578 00:27:13,960 --> 00:27:16,359 mentioned quantum gravity before. How does that fit in? 579 00:27:16,559 --> 00:27:18,519 Speaker 1: Yes, the holy grail of physics. 580 00:27:18,599 --> 00:27:21,279 Speaker 2: That is the ultimate prize. Right now, we have two 581 00:27:21,319 --> 00:27:24,799 different rule books for the universe. We have general relativity, 582 00:27:24,839 --> 00:27:28,720 which handles big stuff like gravity, pancakes, and galaxies, and 583 00:27:28,759 --> 00:27:31,440 we have quantum mechanics, which handles the tiny stuff like 584 00:27:31,559 --> 00:27:33,640 atoms and subatomic particle And. 585 00:27:33,599 --> 00:27:35,440 Speaker 1: They don't get along at all. 586 00:27:35,559 --> 00:27:38,640 Speaker 2: They hate each other, they don't mathematically work together. We 587 00:27:38,720 --> 00:27:42,279 are desperately searching for a theory of quantum gravity, the 588 00:27:42,319 --> 00:27:43,880 one single theory that. 589 00:27:43,960 --> 00:27:46,839 Speaker 1: Unifies them, and solving the dark matter mystery can help 590 00:27:46,920 --> 00:27:47,400 us find it. 591 00:27:48,000 --> 00:27:51,799 Speaker 2: The source argues that, yes, absolutely, if we finally solve 592 00:27:51,839 --> 00:27:54,200 the riddle of dark matter, why the universe looks like 593 00:27:54,200 --> 00:27:56,960 an orc, why the galaxy is spin too fast, it 594 00:27:57,000 --> 00:27:59,440 won't just tell us what the invisible stuff is. It 595 00:27:59,519 --> 00:28:01,440 might give us it's the crucial clue we need to 596 00:28:01,519 --> 00:28:04,119 understand the fundamental nature of quantum gravity. 597 00:28:04,160 --> 00:28:05,759 Speaker 1: It's a two for one deal, two. 598 00:28:05,759 --> 00:28:09,039 Speaker 2: Unsolved mysteries for the price of one. If dark matter 599 00:28:09,119 --> 00:28:11,799 turns out to be a misunderstanding of how gravity works 600 00:28:11,839 --> 00:28:15,000 on a quantum level, it might reveal the bridge between 601 00:28:15,039 --> 00:28:17,519 the quantum world and the cosmic world. 602 00:28:17,680 --> 00:28:21,720 Speaker 1: I love that it turns this frustration, this infuriating creative 603 00:28:21,720 --> 00:28:25,680 writing exercise, into a massive opportunity. The fact that the 604 00:28:25,720 --> 00:28:29,039 model is breaking isn't a failure. It's actually good news. 605 00:28:29,759 --> 00:28:32,680 It means we are about to learn something profound. 606 00:28:32,920 --> 00:28:34,519 Speaker 2: That is the best way to look at it. The 607 00:28:34,559 --> 00:28:38,240 anomalies aren't failures, they are clues. The orc is a clue. 608 00:28:38,400 --> 00:28:40,559 Speaker 1: All right, let's wrap this up. This has been a 609 00:28:40,599 --> 00:28:43,599 wild ride. We started with an orc, moved to a pancake, 610 00:28:43,839 --> 00:28:46,599 realized our scientific model is held together by tape and 611 00:28:46,680 --> 00:28:49,279 creative writing, and we ended up at the holy grail 612 00:28:49,319 --> 00:28:49,799 of physics. 613 00:28:49,839 --> 00:28:51,759 Speaker 2: Just a typical Tuesday and cosmology. 614 00:28:52,160 --> 00:28:54,480 Speaker 1: But there's something really beautiful about it, isn't there. The 615 00:28:54,519 --> 00:28:57,359 source had this lovely reflection at the end of her analysis. 616 00:28:57,720 --> 00:29:00,680 Speaker 2: Yes, it's so easy to get lost and the math 617 00:29:00,799 --> 00:29:03,279 and the sigmas and all the jargon. But if you 618 00:29:03,279 --> 00:29:06,440 step back for a moment, everything we talked about today, 619 00:29:06,519 --> 00:29:10,640 the voids, the pancake, the galaxies, the orc, it all 620 00:29:10,759 --> 00:29:15,480 formed from minuscule quantum fluctuations over billions and billions of. 621 00:29:15,519 --> 00:29:19,160 Speaker 1: Years, Tiny little jitters in the energy of the early universe. 622 00:29:19,319 --> 00:29:24,519 Speaker 2: Tiny jitters, literally random quantum noise that gravity amplified into 623 00:29:24,559 --> 00:29:28,039 the massive cosmic structures we see today. As the host said, 624 00:29:28,079 --> 00:29:29,839 if you ever feel let down by the world, just 625 00:29:29,920 --> 00:29:33,880 remember it's all just quantum fluctuations that evolved into little 626 00:29:33,960 --> 00:29:36,000 human beings crawling around on planets. 627 00:29:36,160 --> 00:29:39,200 Speaker 1: That is weirdly comforting. I'm just a highly organized quantum 628 00:29:39,240 --> 00:29:41,160 fluctuation with a podcast. 629 00:29:40,720 --> 00:29:42,799 Speaker 2: And really the only thing to blame for all of this, 630 00:29:43,000 --> 00:29:45,559 the mess, the mystery, the ork is physics. 631 00:29:45,680 --> 00:29:47,480 Speaker 1: Blame physics. I'm going to use that next time I 632 00:29:47,559 --> 00:29:49,839 relate for a meeting. Sorry, physics made the universe weird 633 00:29:49,839 --> 00:29:51,279 and I got got in the local sheet. 634 00:29:51,440 --> 00:29:53,519 Speaker 2: It might not hold up in court, but it is 635 00:29:53,720 --> 00:29:55,880 on a fundamental level, technically true. 636 00:29:56,000 --> 00:30:00,359 Speaker 1: So here is the summary of today's thrilling thread. We 637 00:30:00,400 --> 00:30:03,799 are very likely living in a dark matter pancake sandwich 638 00:30:03,839 --> 00:30:08,039 between two giant voids. The theory we use to explain 639 00:30:08,160 --> 00:30:12,200 this is struggling to keep up with reality, requiring more 640 00:30:12,240 --> 00:30:15,559 and more creative writing to make sense. And the universe 641 00:30:15,640 --> 00:30:18,720 is wonderfully, stubbornly beautifully strange. 642 00:30:18,880 --> 00:30:19,960 Speaker 2: A perfect summary. 643 00:30:20,119 --> 00:30:21,839 Speaker 1: Now I want to turn this over to you, the listener. 644 00:30:22,200 --> 00:30:25,200 We've presented the evidence, we've shown you the fixes and 645 00:30:25,279 --> 00:30:28,519 the patches the scientists are making to the theory. So 646 00:30:28,640 --> 00:30:29,279 what do you think? 647 00:30:29,440 --> 00:30:31,920 Speaker 2: Yes, that is the real question. Do you think the 648 00:30:32,039 --> 00:30:34,799 dark matter model is just going through some growing pains 649 00:30:34,880 --> 00:30:37,079 and we'll eventually find that particle in a lab and 650 00:30:37,119 --> 00:30:38,920 it will all make sense. Or is it time to 651 00:30:39,000 --> 00:30:40,039 scrap it? 652 00:30:40,079 --> 00:30:42,599 Speaker 1: Is it time to burn the creative writing, the manuscript 653 00:30:42,599 --> 00:30:44,480 and start a new book. Are we missing something big? 654 00:30:44,640 --> 00:30:47,920 Speaker 2: It is the biggest question in modern science, and honestly, 655 00:30:48,079 --> 00:30:50,279 right now your guess is as good as ours. 656 00:30:50,440 --> 00:30:51,880 Speaker 1: Leave a comment let us know where you stand. Are 657 00:30:51,960 --> 00:30:54,599 you team dark matter or are you on team something new. 658 00:30:55,000 --> 00:30:57,400 Speaker 2: I'm very curious to see what people think about this one. 659 00:30:57,599 --> 00:31:00,839 Speaker 1: Me too. As always, thank you for joining us on 660 00:31:00,880 --> 00:31:04,880 this journey through the cosmos. Keep looking up and watch out. 661 00:31:04,720 --> 00:31:06,480 Speaker 2: For the orcs and mind the voids. 662 00:31:06,599 --> 00:31:08,640 Speaker 1: This has been thrilling threads. See you next time.