WEBVTT 1 00:00:03.399 --> 00:00:07.719 Welcome to Bedtime Astronomy. Explore the wonders of the cosmos 2 00:00:07.759 --> 00:00:12.279 with our soothing Bedtime Astronomie podcast. Each episode offers a 3 00:00:12.359 --> 00:00:16.320 gentle journey through the stars, planets, and beyond, perfect for 4 00:00:16.399 --> 00:00:20.239 unwinding after a long day. Let's travel through the mysteries 5 00:00:20.239 --> 00:00:22.440 of the universe as you drift off into a peaceful 6 00:00:22.480 --> 00:00:23.839 slumber under the night sky. 7 00:00:27.000 --> 00:00:29.199 So take a look at a glass of water, Like, 8 00:00:29.399 --> 00:00:32.039 just picture it sitting there right on your kitchen counter. 9 00:00:32.880 --> 00:00:35.799 If you were to take that glass, isolate just a 10 00:00:35.840 --> 00:00:41.320 single drop of it and ask the absolute smartest planetary 11 00:00:41.320 --> 00:00:45.520 physicists on Earth to analyze its atomic signature, well for 12 00:00:45.560 --> 00:00:47.520 the last forty years or so, they would have told 13 00:00:47.520 --> 00:00:52.119 you a very specific, a very dramatic story about where 14 00:00:52.119 --> 00:00:52.600 it came from. 15 00:00:52.640 --> 00:00:53.920 Yeah, a highly dramatic one. 16 00:00:54.000 --> 00:00:55.880 Right. They would have told you that the water you're 17 00:00:55.920 --> 00:00:59.119 about to drink was delivered by this massive bombardment of 18 00:00:59.399 --> 00:01:04.239 icy commet and frozen asteroids from billions of mild away 19 00:01:04.319 --> 00:01:07.359 like from the absolute darkest, coldest edges of the outer 20 00:01:07.439 --> 00:01:08.120 Solar System. 21 00:01:08.280 --> 00:01:11.480 It was basically the ultimate cosmic import business. I mean, 22 00:01:11.480 --> 00:01:14.920 the prevailing scientific consensus was just absolutely locked in on 23 00:01:14.959 --> 00:01:18.560 this idea that the Earth was born dryly dry, yeah, completely, 24 00:01:18.760 --> 00:01:21.799 and that it required this massive chaotic delivery system to 25 00:01:21.879 --> 00:01:23.920 become the blue marble that you know today. 26 00:01:24.120 --> 00:01:26.680 Right, But today we know they were wrong, like completely wrong. 27 00:01:26.799 --> 00:01:27.000 Yeah. 28 00:01:27.000 --> 00:01:29.120 The water in your glass, the ground beneath your feet, 29 00:01:29.159 --> 00:01:31.879 the mountains, the ocean's literally the entire mass of the Earth. 30 00:01:31.879 --> 00:01:34.519 It wasn't imported at all, No, not even a little bit. 31 00:01:34.640 --> 00:01:37.719 It was locally sourced. And we are going to explore 32 00:01:37.840 --> 00:01:43.480 exactly how researchers at ETH Zurich, specifically planetary scientists Paulososi 33 00:01:43.599 --> 00:01:47.200 and Dan Bauer, have completely rewritten the recipe for our planet. 34 00:01:47.239 --> 00:01:48.760 I mean, they've proven that the Earth is a one 35 00:01:48.799 --> 00:01:50.640 hundred percent local creation. 36 00:01:50.799 --> 00:01:54.280 Which is just a massive fundamental paradigm shift. We're talking 37 00:01:54.319 --> 00:01:58.640 about dismantling decades of accepted planetary science. 38 00:01:58.319 --> 00:01:59.239 Here, decades of it. 39 00:01:59.319 --> 00:02:02.159 Yeah, because when you prove that the Earth didn't need 40 00:02:02.200 --> 00:02:06.120 the Outer Solar System to get its water, you aren't 41 00:02:06.159 --> 00:02:08.439 just changing the history of one planet. You are completely 42 00:02:08.479 --> 00:02:13.039 altering our entire understanding of how star systems form. Wow, Yeah, 43 00:02:13.080 --> 00:02:16.360 and how vulnerable elements survive and ultimately, you know what 44 00:02:16.479 --> 00:02:19.199 the actual recipe for a habitable world really looks. 45 00:02:19.000 --> 00:02:21.719 Like, Okay, let's untack this because to really grasp the 46 00:02:21.800 --> 00:02:24.879 magnitude of what Soci and Bower have uncovered, we need 47 00:02:24.919 --> 00:02:28.400 to first thoroughly understand the old consensus, Like, why was 48 00:02:28.439 --> 00:02:31.560 the scientific community so utterly convinced that we needed this 49 00:02:31.639 --> 00:02:35.159 elaborate cosmic delivery service in the first place. Why did 50 00:02:35.240 --> 00:02:37.719 they think that, uh, I think it was up to 51 00:02:37.800 --> 00:02:40.240 forty percent of the Earth's mass had to come from 52 00:02:40.319 --> 00:02:41.400 beyond Jupiter. 53 00:02:41.759 --> 00:02:44.120 Well, it really all comes down to a concept called 54 00:02:44.120 --> 00:02:47.319 the snow line, or sometimes it's called the frost line 55 00:02:47.439 --> 00:02:49.800 in the early Solar System. Okay, so when you look 56 00:02:49.840 --> 00:02:52.400 back for and have billion years before the planets were 57 00:02:52.439 --> 00:02:57.199 actual spheres, the Solar System was just this flat protoplanetary. 58 00:02:56.360 --> 00:02:59.360 Disc basically just a swirling cloud of gas and dust 59 00:02:59.479 --> 00:03:02.599 right the really young, highly energetic. 60 00:03:02.199 --> 00:03:05.560 Sun exactly, and the physics of that disc dictate a 61 00:03:05.680 --> 00:03:08.560 very severe temperature gradient close to the Sun where the 62 00:03:08.639 --> 00:03:12.000 Earth was busy forming. The ambient temperature of this swirling 63 00:03:12.120 --> 00:03:14.960 gas and dust was just incredibly hid an oven, yeah, 64 00:03:15.000 --> 00:03:19.599 a scorching environment, and in that kind of heat, volatile elements, 65 00:03:19.759 --> 00:03:22.439 which are elements and compounds with really low boiling points, 66 00:03:22.680 --> 00:03:25.479 So primarily water, but also things like carbon and nitrogen, 67 00:03:26.080 --> 00:03:28.719 they simply cannot condense into a solid form. They just 68 00:03:28.759 --> 00:03:32.159 remain as a vapor, and the intense solar wind of 69 00:03:32.199 --> 00:03:36.000 the young Sun just relentlessly pushes that vapor outward. 70 00:03:36.280 --> 00:03:40.479 So the inner Solar system is essentially this giant cosmic oven. 71 00:03:40.520 --> 00:03:44.039 I mean, it's like baking a highly specific cake. You 72 00:03:44.080 --> 00:03:47.240 can't bake water into a rock if the ambient temperature 73 00:03:47.280 --> 00:03:49.039 is hot enough to instantly vaporize it. 74 00:03:49.120 --> 00:03:52.319 Right precisely, to find any solid ice, you had to 75 00:03:52.360 --> 00:03:55.560 travel far far out into the disk, like well beyond 76 00:03:55.599 --> 00:03:58.479 the orbit of where Jupiter is today. Lay out there, yeah, 77 00:03:58.520 --> 00:04:02.120 because out there pass the snow line, the temperatures finally 78 00:04:02.199 --> 00:04:05.599 drop low enough for water vapor to actually freeze onto 79 00:04:05.639 --> 00:04:09.319 the tiny dust grains, which then create icy pebbles, and 80 00:04:09.360 --> 00:04:12.439 eventually you get these massive icy asteroids and. 81 00:04:12.439 --> 00:04:14.960 Comets, which naturally leads to the old assumption. If the 82 00:04:15.000 --> 00:04:17.800 Earth formed inside the oven, it must have been baked bone. 83 00:04:17.639 --> 00:04:19.720 Dry, right, that was the logic. 84 00:04:19.480 --> 00:04:22.759 But clearly, you know we have oceans. So the old 85 00:04:22.800 --> 00:04:25.160 logic dictates that once the oven cooled down a bit, 86 00:04:25.279 --> 00:04:27.319 someone or something must have thrown a huge bunch of 87 00:04:27.319 --> 00:04:30.560 ice into it. But if the inner Solar System was 88 00:04:30.600 --> 00:04:33.720 considered this hot dry zone, wasn't the assumption of an 89 00:04:33.720 --> 00:04:36.920 outer system water delivery just entirely logical based on the physics. 90 00:04:37.240 --> 00:04:40.879 Oh absolutely, it made perfect sense based on the older models. 91 00:04:40.959 --> 00:04:43.720 In fact, things like the Grand Tac and other planetary 92 00:04:43.839 --> 00:04:47.839 migration models were heavily relied upon to explain this exact mechanism. 93 00:04:47.959 --> 00:04:48.720 Grand Tach. 94 00:04:48.920 --> 00:04:52.759 Yeah. So scientists hypothesize that the giant planets, particularly Jupiter 95 00:04:52.800 --> 00:04:56.560 and Saturn, they actually migrated inward and then outward during 96 00:04:56.600 --> 00:04:57.480 their early formation. 97 00:04:57.759 --> 00:05:00.160 Oh wow, they moved around Yeah. 98 00:05:00.040 --> 00:05:03.439 Yeah a lot. And this gravitational dance would have totally 99 00:05:03.480 --> 00:05:07.959 destabilized the orbits of countless icy, water rich bodies in 100 00:05:08.040 --> 00:05:10.959 the outer Solar System. It would have sent them hurtling 101 00:05:11.040 --> 00:05:14.160 inward to crash right into the early dry Earth. 102 00:05:14.240 --> 00:05:18.399 So it was just this violently chaotic mechanism designed specifically 103 00:05:18.439 --> 00:05:19.720 to solve the water problem. 104 00:05:19.839 --> 00:05:23.800 Exactly. It made perfect logical sense based on the thermodynamic 105 00:05:23.879 --> 00:05:26.319 models of the time. But what's fascinating here is that 106 00:05:26.360 --> 00:05:31.720 Socium Bower's new calculations completely dismantle that entire logic completely. Yeah, 107 00:05:31.720 --> 00:05:34.519 their analysis reveals that material from the outer Solar System 108 00:05:34.759 --> 00:05:38.480 accounts for less than two percent of Earth mass, and honestly, 109 00:05:38.560 --> 00:05:41.600 their data suggests it's potentially zero percent zero. 110 00:05:42.079 --> 00:05:45.399 I mean, the imported ingredients simply aren't there at all. 111 00:05:45.560 --> 00:05:50.160 The Earth was built entirely from the dry, supposedly volatile 112 00:05:50.199 --> 00:05:53.240 stripped materials of the inner Solar System. Yes, which is 113 00:05:53.360 --> 00:05:57.000 just absolutely staggering to think about. But it begs a 114 00:05:57.000 --> 00:06:01.000 really massive question if we are completely overhauling of forty 115 00:06:01.040 --> 00:06:04.279 year old consensus. I mean, the proof has to be ironclad. 116 00:06:04.360 --> 00:06:06.279 Oh, it has to be undeniable. 117 00:06:05.759 --> 00:06:08.040 Right, because we weren't there four and a half billion 118 00:06:08.120 --> 00:06:10.519 years ago to watch the Earth of crete. So how 119 00:06:10.560 --> 00:06:13.680 do we definitively prove where a rock actually formed? 120 00:06:13.920 --> 00:06:16.639 Well, we look at the atomic fingerprints locked inside the 121 00:06:16.720 --> 00:06:22.240 rocks themselves. Specifically, we look at something called nucleosynthetic isotopic anomalies. 122 00:06:22.360 --> 00:06:24.759 Okay, let's dive deep into that, because this is really 123 00:06:24.839 --> 00:06:27.879 the core of the whole discovery. When we talk about isotopes, 124 00:06:27.959 --> 00:06:30.360 we aren't just talking about slight variations in weight, are 125 00:06:30.399 --> 00:06:33.759 we We are actually talking about the distinct chemical memory 126 00:06:33.800 --> 00:06:34.839 of dying stars. 127 00:06:35.079 --> 00:06:37.920 That is the perfect way to phrase it. Honestly, Before 128 00:06:37.959 --> 00:06:40.920 our Sun even ignited, the giant cloud of gas and 129 00:06:41.040 --> 00:06:44.279 dust that would eventually become our Solar System was seated 130 00:06:44.319 --> 00:06:46.600 with material from various stellar. 131 00:06:46.240 --> 00:06:48.480 Phenomena, like what kind of phenomena. 132 00:06:48.680 --> 00:06:51.639 Well, some dust came from the gentle slow shedding of 133 00:06:51.680 --> 00:06:57.399 red giant stars, and other dust came from violently explosive supernovae, and. 134 00:06:57.399 --> 00:07:01.199 Each of those different stellar events produces diff diferent flavors basically, 135 00:07:01.639 --> 00:07:04.199 or isotopes of the elements we know, right, like titanium 136 00:07:04.240 --> 00:07:04.879 or chromium. 137 00:07:04.959 --> 00:07:09.680 Exactly, and crucially, this presolar cloud was not perfectly mixed. 138 00:07:09.720 --> 00:07:13.360 It wasn't uniform, okay, it was. It was like a 139 00:07:13.399 --> 00:07:17.279 really poorly stirred cake batter. There were pockets with a 140 00:07:17.319 --> 00:07:21.120 slightly higher concentration of supernova dust, and then other pockets 141 00:07:21.160 --> 00:07:23.920 with slightly more red giant dust. Right and as the 142 00:07:23.959 --> 00:07:27.079 protoplanetary disc formed and started spinning around the young Sun, 143 00:07:27.839 --> 00:07:31.439 these subtle variations in the isotopic ratios these anomalies were 144 00:07:31.439 --> 00:07:34.399 talking about, they were permanently preserved in the specific regions 145 00:07:34.399 --> 00:07:35.279 where they coalesced. 146 00:07:35.439 --> 00:07:37.959 So if a rock forms in the inner Solar System, 147 00:07:38.319 --> 00:07:41.480 it permanently locks in the specific isotopic batter of that 148 00:07:41.519 --> 00:07:44.639 local neighborhood. Yes, and if it forms out past Jupiter, 149 00:07:44.839 --> 00:07:47.720 it locks in a completely different isotopic signature. So it's 150 00:07:47.759 --> 00:07:50.040 basically a prominent built in barcode. 151 00:07:50.120 --> 00:07:53.600 It is a literal barcode. But you know, reading that 152 00:07:53.680 --> 00:07:58.360 barcode has historically been incredibly difficult for scientists. For decades, 153 00:07:58.800 --> 00:08:03.240 the entire field of cosmo chemistry relied almost exclusively on 154 00:08:03.279 --> 00:08:06.199 the isotopes of a single element to towart to trace 155 00:08:06.279 --> 00:08:09.639 these origins, which was oxygen, right, Yes, oxygen? 156 00:08:09.800 --> 00:08:12.959 Why just oxygen? Is it just because it's everywhere largely? 157 00:08:13.040 --> 00:08:16.639 Yeah, Oxygen is incredibly abundant in rocky materials. I mean, 158 00:08:16.720 --> 00:08:19.519 it makes up a huge percentage of silicate minerals. So 159 00:08:19.600 --> 00:08:22.079 it was simply the easiest thing to measure in the lab. Sure, 160 00:08:22.199 --> 00:08:25.959 but relying on oxygen comes with a severe limitation. Oxygen 161 00:08:26.000 --> 00:08:29.600 is a highly volatile element, and in the early Solar 162 00:08:29.639 --> 00:08:32.440 system a vast vast amount of it was just floating 163 00:08:32.440 --> 00:08:35.879 around as a gas like carbon monoxide or water vapor. 164 00:08:36.120 --> 00:08:38.440 Ah, So it interacts with stuff, it mixes. 165 00:08:38.279 --> 00:08:39.200 It interacts constantly. 166 00:08:39.320 --> 00:08:39.440 YEA. 167 00:08:39.600 --> 00:08:42.200 The oxygen in a solid grain of dust can very 168 00:08:42.200 --> 00:08:45.000 easily exchange its isotopes with the oxygen in the surround 169 00:08:45.000 --> 00:08:48.399 of gas. It's totally fluid. Oh wow. Therefore, the oxygen 170 00:08:48.399 --> 00:08:51.519 isotopic signature of a rock can be altered, blurred, or 171 00:08:51.759 --> 00:08:55.480 just completely overwritten by its environment long long after it initially. 172 00:08:55.039 --> 00:08:57.000 Formed, so it's not a reliable barcot at all. 173 00:08:57.240 --> 00:09:01.759 No, using oxygen to trace a rock origin is like 174 00:09:01.799 --> 00:09:03.919 trying to trace the origin of a specific drop of 175 00:09:03.960 --> 00:09:07.080 water in a flowing river. It's just too easily compromised. 176 00:09:07.240 --> 00:09:09.559 Which brings us to the real breakthrough. In the early 177 00:09:09.600 --> 00:09:13.080 twenty tens, researchers realized they needed to look at elements 178 00:09:13.080 --> 00:09:16.879 that don't interact right, elements that just refuse to change 179 00:09:16.919 --> 00:09:19.919 their signature no matter what. And they landed on things 180 00:09:19.960 --> 00:09:24.600 like titanium and chromium. Yes, why those specific elements. 181 00:09:24.159 --> 00:09:28.679 Because titanium and chromium are what we call highly refractory. 182 00:09:28.159 --> 00:09:29.799 Elements, meaning they like it hot. 183 00:09:29.759 --> 00:09:33.200 Extremely hot. They candense from a gas into a solid 184 00:09:33.519 --> 00:09:37.399 at incredibly high temperatures. We're talking well over a thousand 185 00:09:37.399 --> 00:09:38.159 degrees kelvin. 186 00:09:38.279 --> 00:09:38.799 Wow. 187 00:09:38.879 --> 00:09:41.279 This means they were among the very first elements to 188 00:09:41.279 --> 00:09:44.759 actually solidify out of the hot solar nebula. And here's 189 00:09:44.799 --> 00:09:47.960 the key. Once they lock into a solid mineral structure, 190 00:09:48.159 --> 00:09:51.120 they absolutely do not exchange isotopes with the surrounding gas. 191 00:09:51.120 --> 00:09:54.759 They are stubborn, very stubborn. They perfectly preserve the exact 192 00:09:54.840 --> 00:09:58.639 nucleosynthetic signature of the local dust from the earliest possible 193 00:09:58.720 --> 00:09:59.799 moments of the Solar systems. 194 00:09:59.840 --> 00:10:02.559 For so, they are the perfect witnesses. They saw the 195 00:10:02.600 --> 00:10:05.679 Solar system form, and they locked their memory in a vault. 196 00:10:05.879 --> 00:10:09.759 And once planetary scientists started using these refractory elements, it 197 00:10:09.840 --> 00:10:12.440 completely changed the map of the Solar System, didn't it. 198 00:10:12.440 --> 00:10:16.360 It allowed them to split all meteorites into two very distinct, 199 00:10:16.519 --> 00:10:18.320 unarguable categories. 200 00:10:18.879 --> 00:10:22.279 It did. You had the non carbonaceous meteorites, which formed 201 00:10:22.440 --> 00:10:26.279 exclusively in the inner Solar System, and then the carbonaceous metiaorites, 202 00:10:26.279 --> 00:10:29.360 which formed way out in the outer Solar System, passed 203 00:10:29.440 --> 00:10:32.919 the orbit of Jupiter and contained significantly higher amounts of 204 00:10:32.960 --> 00:10:33.679 water and carbon. 205 00:10:33.720 --> 00:10:36.759 Okay, here's where it gets really interesting, because if we've 206 00:10:36.799 --> 00:10:41.039 had this incredibly precise titanium and chromium fingerprinting method since 207 00:10:41.080 --> 00:10:44.080 the early twenty tens, and we've had meteorite samples from 208 00:10:44.080 --> 00:10:47.320 the asteroid Vesta and from Mars for decades, right, right, half, 209 00:10:47.480 --> 00:10:49.639 Then why are we only finding out right now that 210 00:10:49.679 --> 00:10:53.080 the Earth is entirely non carbonaceous? Why didn't someone figure 211 00:10:53.080 --> 00:10:56.120 this out ten years ago? Was the old oxygen only 212 00:10:56.200 --> 00:10:58.759 method just too blurry or was there more to it? 213 00:10:58.840 --> 00:11:02.960 Well, if we connect this to the bigger picture, analyzing 214 00:11:03.120 --> 00:11:06.320 just titanium and chromium is still only giving you a 215 00:11:06.320 --> 00:11:09.919 two dimensional view of a vastly complex system. If you 216 00:11:09.919 --> 00:11:13.879 want to definitively prove that Earth contains absolutely zero percent 217 00:11:14.480 --> 00:11:18.000 outer Solar System material, you really cannot rely on just 218 00:11:18.039 --> 00:11:18.840 two data. 219 00:11:18.559 --> 00:11:21.840 Points, even if they are highly reliable data points exactly. 220 00:11:21.879 --> 00:11:24.559 Think of it like a forensic investigation. If you find 221 00:11:24.600 --> 00:11:28.080 DNA at a crime scene, checking just two genetic markers 222 00:11:28.159 --> 00:11:30.440 might tell you the suspect is from a certain hemisphere, 223 00:11:31.039 --> 00:11:32.759 but it won't give you their exact identity. 224 00:11:32.840 --> 00:11:34.360 Right. The error bars are just too wide? 225 00:11:34.480 --> 00:11:38.360 Yes, If the oxotopic data for Earth, Mars, and the 226 00:11:38.399 --> 00:11:41.840 carbonaceous meteorites are plotted on a simple two dimensional graph 227 00:11:42.240 --> 00:11:45.559 using just titanium and chromium, the data points have these 228 00:11:45.600 --> 00:11:49.080 tiny margins of error that can sometimes overlap oh I see, 229 00:11:49.159 --> 00:11:51.960 and that overlap leaves room for doubt. It leaves room 230 00:11:52.000 --> 00:11:54.240 for a science is holding onto the old theory to say, well, 231 00:11:54.399 --> 00:11:56.960 maybe there's a five percent mix of carbonaceous material in 232 00:11:57.000 --> 00:11:57.840 there as a little. 233 00:11:57.600 --> 00:12:00.519 Cosmic import model still had room to breathe side those 234 00:12:00.559 --> 00:12:01.919 tiny margins of error. 235 00:12:02.200 --> 00:12:06.639 Precisely, to truly eliminate the margins of error, you have 236 00:12:06.720 --> 00:12:10.559 to drastically increase the dimensionality of your data. And that 237 00:12:10.720 --> 00:12:13.679 is exactly what Powell, associ and dan Bauer did. They 238 00:12:13.679 --> 00:12:16.480 didn't go out and discover some brand new shiny rock. 239 00:12:17.240 --> 00:12:21.879 They orchestrated a total triumph of methodology. They gathered existing 240 00:12:21.919 --> 00:12:25.279 isotopic data on ten different element systems ten. 241 00:12:25.320 --> 00:12:27.919 So we're moving from a simple two dimensional graph to 242 00:12:28.000 --> 00:12:30.480 a ten dimensional mathematical space exactly. 243 00:12:30.679 --> 00:12:36.440 They looked at the isotopes of iron, calcium, molybdenum, ruthenium, tungsten, neodymium, 244 00:12:36.559 --> 00:12:39.480 and several others. Wow, and each of these elements condenses 245 00:12:39.480 --> 00:12:43.720 at completely different temperatures and has slightly different nucleosynthetic origins. 246 00:12:43.879 --> 00:12:47.000 But human brains can't even visualize a ten dimensional graph. 247 00:12:47.120 --> 00:12:48.840 I mean, how do you even begin to map the 248 00:12:48.879 --> 00:12:52.759 isotopic signature of Earth against meteorites in ten dimensions. 249 00:12:52.799 --> 00:12:54.120 Well, you have to step out of the realm of 250 00:12:54.120 --> 00:12:57.440 traditional geochemistry and enter the realm of advanced data science. 251 00:12:58.039 --> 00:13:03.440 The researchers utilize specialized to test calculations, specifically dimensionality reduction techniques. 252 00:13:03.679 --> 00:13:07.000 Think of methods akin to principal component analysis or PCA. 253 00:13:07.320 --> 00:13:10.159 Okay, break that down for us, because this sounds like 254 00:13:10.279 --> 00:13:14.480 taking a dusty library of old, handwritten census records that 255 00:13:14.639 --> 00:13:18.519 historians have stared at for decades, applying a modern statistical 256 00:13:18.519 --> 00:13:22.279 algorithm to them, and suddenly uncovering a completely hidden family 257 00:13:22.320 --> 00:13:26.120 tree that rewrites history. How does a tool like PCA 258 00:13:26.440 --> 00:13:28.840 actually work on chemical data? 259 00:13:29.399 --> 00:13:32.519 That's a great analogy. So imagine you have this massive, 260 00:13:32.600 --> 00:13:36.039 chaotic cloud of data points representing all these different meteorites, 261 00:13:36.360 --> 00:13:38.679 and they are floating around in a ten dimensional room. 262 00:13:39.000 --> 00:13:41.360 To the naked eye, it just looks like random noise. 263 00:13:41.279 --> 00:13:42.519 Just a massive dots, right. 264 00:13:42.960 --> 00:13:46.759 But PCA is a mathematical algorithm that essentially rotates that room. 265 00:13:47.159 --> 00:13:49.679 It looks for the specific angles where the data naturally 266 00:13:49.720 --> 00:13:52.840 lines up. It finds the underlying structure, the hidden axes 267 00:13:52.879 --> 00:13:56.000 of variants that explain the most significant differences between all 268 00:13:56.039 --> 00:13:56.600 the samples. 269 00:13:56.679 --> 00:13:59.679 It's almost like taking a really complex three dimensional sculpture 270 00:13:59.679 --> 00:14:02.039 and rotating it under a single light until it casts 271 00:14:02.080 --> 00:14:05.639 the perfectly clear, recognizable two dimensional shadow on the wall. 272 00:14:06.000 --> 00:14:09.120 You are just finding the specific mathematical perspective that reveals 273 00:14:09.159 --> 00:14:11.039 the truth hidden in all that complexity. 274 00:14:11.320 --> 00:14:13.720 That is a phenomenal way to picture it. And when 275 00:14:13.759 --> 00:14:17.360 Solcien Bower applied these statistical models to the ten isotope 276 00:14:17.399 --> 00:14:21.159 data set, the shadow at cast was undeniable in this 277 00:14:21.279 --> 00:14:25.840 high dimensional space. All the non carbonaceous meteorites, so the 278 00:14:25.879 --> 00:14:29.759 inner Solar System rocks, they formed a perfectly straight, super 279 00:14:29.799 --> 00:14:32.960 tight line. Mars is right on that line, the asteroid 280 00:14:33.039 --> 00:14:35.759 Vesta is exactly on that line, and the Earth sits 281 00:14:35.759 --> 00:14:37.399 squarely on that exact same line. 282 00:14:37.440 --> 00:14:40.919 And where are the carbonaceous meteorites, like the icy water 283 00:14:40.960 --> 00:14:43.360 bearing rocks from the outer Solar System. 284 00:14:43.399 --> 00:14:46.480 They are completely segregated. They form their own separate, distinct 285 00:14:46.480 --> 00:14:49.519 cluster in a totally different area of the data space. 286 00:14:49.759 --> 00:14:53.759 There is zero overlap, no margin of error whatsoever. 287 00:14:53.639 --> 00:14:56.679 Which brings up a really critical point about how science 288 00:14:56.759 --> 00:15:00.440 is often conducted. For decades, researchers were looking at these 289 00:15:00.440 --> 00:15:02.440 exact same rocks, but they were looking at them through 290 00:15:02.440 --> 00:15:06.039 the lens of a preconceived physical assumption. Weren't they Absolutely 291 00:15:06.159 --> 00:15:09.639 they assumed the Earth needed outer solar system water, so 292 00:15:09.679 --> 00:15:12.960 when they built their models, they inherently biased the math 293 00:15:13.080 --> 00:15:14.360 to allow for a mixture. 294 00:15:14.720 --> 00:15:18.919 Yes, we call those Bayesian pryors. When you construct a 295 00:15:18.960 --> 00:15:22.360 model to test a hypothesis, you often feed it prior 296 00:15:22.399 --> 00:15:25.240 assumptions based on what you already think. You know, right, 297 00:15:25.480 --> 00:15:29.080 The older models basically instructed the algorithm, hey, find the 298 00:15:29.080 --> 00:15:32.039 best mixture of inner and outer material to create the Earth, 299 00:15:32.840 --> 00:15:35.960 and the algorithm, just doing what it was told, found 300 00:15:36.000 --> 00:15:38.799 a mathematical way to mix them. Even i Physically it 301 00:15:38.840 --> 00:15:39.879 was highly improbable. 302 00:15:40.000 --> 00:15:42.320 It's the old adage, right, if you torture the data 303 00:15:42.360 --> 00:15:45.120 long enough, it will eventually confess to anything exactly. 304 00:15:45.759 --> 00:15:48.879 And the real brilliance of Bauers' contribution here is that 305 00:15:48.919 --> 00:15:52.360 their model is entirely agnostic. They completely stripped away all 306 00:15:52.440 --> 00:15:56.519 those thermodynamic assumptions about hot inner disks and migrating comets. 307 00:15:56.600 --> 00:15:58.000 They just let the data talk. 308 00:15:58.159 --> 00:16:00.399 They just let the cold hard numbers of ten different 309 00:16:00.440 --> 00:16:04.159 isotopic systems speak for themselves, and the numbers do not lie. 310 00:16:04.519 --> 00:16:07.320 The calculations are entirely robust because they rely solely on 311 00:16:07.360 --> 00:16:11.279 the data itself. The Earth is a closed system. It 312 00:16:11.360 --> 00:16:13.480 is one hundred percent non carbonaceous. 313 00:16:13.600 --> 00:16:15.440 Okay, so what does this all mean? Because this is 314 00:16:15.480 --> 00:16:18.279 where the physical reality of the Solar System starts to 315 00:16:18.360 --> 00:16:22.000 really break my brain. Because if the data undeniably proves 316 00:16:22.000 --> 00:16:25.399 that outer and inner Solar System materials never mixed, if 317 00:16:25.399 --> 00:16:28.679 the carbonaceous rocks and the non carbonaceous rocks never mingled 318 00:16:28.720 --> 00:16:31.240 for millions of years while the planet's were forming, we 319 00:16:31.360 --> 00:16:34.279 have to ask a massive physical question what was physically 320 00:16:34.399 --> 00:16:36.879 keeping them apart? I mean, the pertal planetary disc is 321 00:16:36.919 --> 00:16:40.519 a swirling, violent hurricane of gas and dust. Things should 322 00:16:40.519 --> 00:16:41.960 be crashing into each other constantly. 323 00:16:41.960 --> 00:16:44.120 They should, which means there had to be a massive 324 00:16:44.480 --> 00:16:48.039 physical barrier, a dam, and that dam is the biggest, 325 00:16:48.039 --> 00:16:49.879 heaviest bully in the planetary playground. 326 00:16:50.120 --> 00:16:53.000 Jupiterjupiter, Jupiter. But I want to push back on this 327 00:16:53.039 --> 00:16:55.639 little because the mechanics of how Jupiter acts as a 328 00:16:55.679 --> 00:17:00.480 barrier seem entirely counterintuitive to me. Jupiter is massive, it 329 00:17:00.480 --> 00:17:05.000 has immense gravity. Wouldn't a giant gravitational vacuum cleaner actually 330 00:17:05.000 --> 00:17:07.440 pull more icy comets and rocks from the outer Solar 331 00:17:07.440 --> 00:17:10.079 System inward. How does a massive planet create a wall? 332 00:17:10.240 --> 00:17:13.200 That is exactly the right question to ask, because it 333 00:17:13.279 --> 00:17:16.559 highlights the difference between static gravity and the fluid dynamics 334 00:17:16.599 --> 00:17:20.160 of a protoplanetary disc. You were thinking of Jupiter as 335 00:17:20.279 --> 00:17:22.960 just a heavyweight sitting in empty space, but you have 336 00:17:23.000 --> 00:17:25.960 to remember the environment it was in. Jupiter is forming 337 00:17:26.079 --> 00:17:30.599 inside a massive rotating disk of thick, viscous gas. 338 00:17:30.880 --> 00:17:33.480 Okay, so it's more like a giant rock moving rapidly 339 00:17:33.480 --> 00:17:34.359 through a thick fluid. 340 00:17:34.400 --> 00:17:38.599 Precisely as Jupiter grew, and it grew incredibly fast, it 341 00:17:38.640 --> 00:17:42.079 created huge amounts of hydrogen and helium. Its immense gravity 342 00:17:42.119 --> 00:17:45.440 began to actually interact with the surrounding gas. It creates 343 00:17:45.519 --> 00:17:48.599 what are known as limb blad resonance resonance there. Yeah, 344 00:17:48.720 --> 00:17:51.920 as Jupiter orbits, it generates these massive spiral density waves 345 00:17:51.920 --> 00:17:54.200 in the gas. It's actually very much like how a 346 00:17:54.240 --> 00:17:56.319 boat creates a wake as it moves through water. 347 00:17:56.440 --> 00:17:58.799 Oh I see, so it's actively pushing the fluid away 348 00:17:58.799 --> 00:17:59.359 from its orbit. 349 00:17:59.559 --> 00:18:03.279 Yes, The gravitational torque from Jupiter literally clears a physical 350 00:18:03.319 --> 00:18:06.319 gap in the protoplanetary disk. It sweeps its entire orbit 351 00:18:06.359 --> 00:18:08.960 clean of gas and dust. But it does more than 352 00:18:09.039 --> 00:18:11.640 just make an empty lane. By pushing the gas away 353 00:18:11.720 --> 00:18:14.759 so violently, it creates a massive pressure bump just outside 354 00:18:14.799 --> 00:18:16.319 its orbit, a pressure. 355 00:18:16.000 --> 00:18:18.599 Bump like water piling up against a physical dam. 356 00:18:18.680 --> 00:18:22.279 Exactly like that. Now, consider the dust in the icy pebbles, 357 00:18:22.680 --> 00:18:26.400 the carbonaceous meteorites that are forming out beyond Jupiter. In 358 00:18:26.440 --> 00:18:30.279 a normal disk without a giant planet, these pebbles experience 359 00:18:30.400 --> 00:18:33.880 gas drag. They feel friction against the gas, they lose 360 00:18:33.920 --> 00:18:37.960 angular momentum, and they naturally spiral inward towards the Sun. Right. 361 00:18:38.440 --> 00:18:41.880 This inward drift is a fundamental mechanism of how planets form. 362 00:18:42.160 --> 00:18:45.519 So they are actively trying to drift inward toward where 363 00:18:45.559 --> 00:18:46.759 the Earth is forming right. 364 00:18:47.160 --> 00:18:49.759 But when they hit that high pressure ridge created by 365 00:18:49.839 --> 00:18:53.759 Jupiter's wake, the physics suddenly change. The gas in that 366 00:18:53.799 --> 00:18:56.880 pressure bump is actually orbiting slightly faster than the normal 367 00:18:56.920 --> 00:19:00.400 Caplerian speed. This means the gas drag suddenly acts as 368 00:19:00.400 --> 00:19:04.240 a tailwind rather than a headwind for the pebbles. Wait, really, yes, 369 00:19:04.480 --> 00:19:07.960 the inward drift stops completely. The pebbles become physically trapped 370 00:19:07.960 --> 00:19:11.000 in this high pressure zone. Outside Jupiter's orbit, they can't 371 00:19:11.039 --> 00:19:12.039 move inward anymore. 372 00:19:12.200 --> 00:19:15.799 That is just brilliant. Did Jupiter effectively act as a 373 00:19:15.799 --> 00:19:19.119 cosmic bouncer standing at the velvet rope of the asteroid belt, 374 00:19:19.640 --> 00:19:24.759 physically blocking all those carbonaceous water bitch meteorites from entering 375 00:19:24.799 --> 00:19:26.160 the inner VIP section. 376 00:19:26.400 --> 00:19:29.079 That is exactly what happened. It's not that Jupiter's physically 377 00:19:29.119 --> 00:19:32.079 blocking every single rock with its body. It's that Jupiter 378 00:19:32.279 --> 00:19:36.880 fundamentally altered the fluid dynamics of the antiresolar system. It 379 00:19:36.960 --> 00:19:41.319 created a hydrodynamic dam that the icy rocks physically could 380 00:19:41.319 --> 00:19:45.119 not cross. Wow, and scientists knew Jupiter card to gap. 381 00:19:45.200 --> 00:19:49.559 That wasn't a secret. But until this specific multidimensional isotopic 382 00:19:49.599 --> 00:19:53.400 analysis by Saucy and Bower, the actual permeability of that 383 00:19:53.440 --> 00:19:55.039 barrier remained a mystery. 384 00:19:54.839 --> 00:19:58.079 Right like did some icy comets manage to slip past. 385 00:19:57.920 --> 00:20:00.400 The velvet rope exactly? We didn't know if it's magnificant 386 00:20:00.440 --> 00:20:02.799 amount of material managed to leak through the dam over 387 00:20:02.839 --> 00:20:05.720 millions of years. But this new analysis proves the dam 388 00:20:05.759 --> 00:20:09.559 held almost perfectly. The barrier was incredibly tight. Almost no 389 00:20:09.680 --> 00:20:12.960 material from beyond Jupiter flowed inward. Toward Earth. The two 390 00:20:13.039 --> 00:20:14.440 zones were strictly segregated. 391 00:20:14.519 --> 00:20:17.799 Jupiter was the great divider, which is an incredible piece 392 00:20:17.839 --> 00:20:22.440 of planetary mechanics, but it immediately brings up a monumental, 393 00:20:22.559 --> 00:20:26.920 inastabable paradox. The dam held the icy comets from the 394 00:20:26.960 --> 00:20:30.839 outer Solar System were trapped behind Jupiter. They never reached Earth. 395 00:20:31.519 --> 00:20:33.400 Yet I can go to my kitchen right now and 396 00:20:33.400 --> 00:20:36.440 turn on the tap and water comes out. If Earth 397 00:20:36.519 --> 00:20:41.359 only ever accumulated local, dry, non carbonaceous rocks, where on 398 00:20:41.359 --> 00:20:43.119 Earth did the oceans actually come from? 399 00:20:43.240 --> 00:20:46.559 You have hit the exact center of the new mystery. 400 00:20:46.680 --> 00:20:50.319 This raises an important question because by solving the isotopic 401 00:20:50.359 --> 00:20:54.319