WEBVTT 1 00:00:01.480 --> 00:00:05.599 Welcome to the quart Side Quantum Physics Podcast, an exploration 2 00:00:05.679 --> 00:00:10.880 of the fundamental structure of reality where quantum laws govern matter, energy, 3 00:00:11.199 --> 00:00:16.239 and information. Here, uncertainty is a feature, not a flaw, 4 00:00:16.719 --> 00:00:19.239 and understanding begins at the smallest scales. 5 00:00:27.640 --> 00:00:32.920 Imagine trying to read a microscopic text message, like really microscopic, 6 00:00:33.320 --> 00:00:36.000 But the only magnifying glass that's actually powerful enough to 7 00:00:36.000 --> 00:00:39.759 read those tiny letters is well, it's roughly the size 8 00:00:39.799 --> 00:00:41.439 of the Milky Way galaxy. 9 00:00:41.039 --> 00:00:43.759 Which is quite the infrastructure problem, right. 10 00:00:43.560 --> 00:00:46.479 I mean that is the exact, frankly absurd position that 11 00:00:46.560 --> 00:00:49.640 modern physicists find themselves in today. Okay, let's unpack this 12 00:00:49.759 --> 00:00:52.200 because our mission today for this deep dive is to 13 00:00:52.280 --> 00:00:58.240 understand the fundamental building blocks of the universe, and more specifically, 14 00:00:58.280 --> 00:01:01.119 how scientists are attempting to prove the existence of something 15 00:01:01.159 --> 00:01:03.640 that they literally physically cannot see. 16 00:01:03.840 --> 00:01:06.519 Yeah, it really is sort of the ultimate cosmic taunt 17 00:01:07.079 --> 00:01:12.120 Nature have seemingly hidden the master blueprint of reality behind 18 00:01:12.120 --> 00:01:15.719 this massive energy barrier that humanity may just never be 19 00:01:15.760 --> 00:01:17.719 able to cross physically at least. 20 00:01:17.760 --> 00:01:20.640 But before we get to the invisible strings and the 21 00:01:20.680 --> 00:01:23.000 galaxy size magnifying glasses, I feel like, we have to 22 00:01:23.000 --> 00:01:26.000 talk about the crisis, the thing that forced physicists into 23 00:01:26.040 --> 00:01:29.239 this corner in the first place. Right, The standoff exactly, 24 00:01:29.319 --> 00:01:32.959 the ultimate standoff in physics, which is basically this massive 25 00:01:33.000 --> 00:01:36.719 clash between the incredibly massive and the impossibly tiny. 26 00:01:36.840 --> 00:01:39.280 That is the core of it. Yeah, yeah, because for gosh, 27 00:01:39.359 --> 00:01:42.480 about a century now, physics has been relying on two 28 00:01:42.560 --> 00:01:44.560 completely different rule books to describe how the. 29 00:01:44.560 --> 00:01:47.359 Universe works, and they do not like each other. 30 00:01:47.439 --> 00:01:50.920 Not at all. So on the grand scale, we use 31 00:01:50.959 --> 00:01:53.560 Einstein's general theory of relativity. 32 00:01:53.000 --> 00:01:54.680 The heavy lifter Exactly. 33 00:01:54.760 --> 00:01:58.879 It's this beautifully elegant framework that explains gravity. It treats 34 00:01:58.920 --> 00:02:03.680 space and time like a like a smooth, continuous fabric. 35 00:02:03.760 --> 00:02:07.359 It predicts how planets orbit, how galaxies collide, black hole, 36 00:02:07.480 --> 00:02:08.240 all the big stuff. 37 00:02:08.360 --> 00:02:11.000 Right, So it makes perfect sense. It's super predictable, and 38 00:02:11.039 --> 00:02:14.199 it works flawlessly when you're dealing with anything large, and. 39 00:02:14.199 --> 00:02:16.360 This is a massive But the moment you zoom in 40 00:02:16.400 --> 00:02:19.400 to the atomic or you know, sub atomic level, general 41 00:02:19.439 --> 00:02:21.159 relativity just completely falls apart. 42 00:02:21.240 --> 00:02:23.159 It just stops working pretty. 43 00:02:22.919 --> 00:02:26.159 Much because down there the universe is governed by quantum 44 00:02:26.159 --> 00:02:30.439 mechanics and the quantum realm is well, it is not 45 00:02:30.479 --> 00:02:35.120 a smooth fabric. It is a jittery, chaotic, highly unpredictable place. 46 00:02:35.639 --> 00:02:38.560 Particles pop in and out of existence, and things only 47 00:02:38.599 --> 00:02:41.759 happen in these discrete, choppy, little jumps. 48 00:02:41.919 --> 00:02:44.120 So we have this smooth, heavy rule book for the 49 00:02:44.120 --> 00:02:48.400 big stuff and a jittery, completely chaotic rule book for 50 00:02:48.439 --> 00:02:51.199 the tiny stuff, which you know, if I'm listening to 51 00:02:51.240 --> 00:02:53.319 this right now, I'm probably thinking, okay, so just use both, 52 00:02:53.680 --> 00:02:56.319 like use the big book for planets and the small 53 00:02:56.319 --> 00:02:57.479 book for atoms. 54 00:02:57.120 --> 00:02:59.800 And honestly, that works perfectly ninety nine percent of the time. 55 00:03:00.039 --> 00:03:02.560 Can get away with it, right, But the crisis hits 56 00:03:02.719 --> 00:03:04.360 when you are forced to deal with something that is 57 00:03:04.400 --> 00:03:09.520 both incredibly massive and incredibly tiny at the exact same time. Oh, 58 00:03:09.599 --> 00:03:11.800 like what we'll think about the very center of a 59 00:03:11.840 --> 00:03:15.840 black hole, yeah, or the very first moment of big bang. 60 00:03:16.439 --> 00:03:18.919 In those extreme, extreme scenarios, you have to combine the 61 00:03:18.960 --> 00:03:20.800 two rule books. You have to figure out how gravity 62 00:03:20.840 --> 00:03:24.319 operates at the quantum level, quantum gravity exactly. Finding a 63 00:03:24.360 --> 00:03:27.319 theory of quantum gravity is the holy grail. But when 64 00:03:27.319 --> 00:03:30.080 you smash those two math equations together. 65 00:03:30.080 --> 00:03:33.560 What actually happens, Like mathematically. 66 00:03:32.759 --> 00:03:35.599 The math literally vomits out infinities. 67 00:03:35.639 --> 00:03:36.719 Wait, infinities. 68 00:03:36.840 --> 00:03:40.560 Yeah, So, in a probability equation, a result of one 69 00:03:40.800 --> 00:03:43.520 means something is one hundred percent guaranteed to happen, and 70 00:03:43.599 --> 00:03:46.599 infinity means a probability greater than one hundred percent. 71 00:03:46.400 --> 00:03:49.360 Which makes absolutely zero sense physically none. 72 00:03:49.680 --> 00:03:53.599 It's the universe's fundamental code. Just flashing of fatal error message. 73 00:03:53.879 --> 00:03:56.479 The math is telling us, hey, you are missing a 74 00:03:56.560 --> 00:03:57.479 crucial piece of the. 75 00:03:57.400 --> 00:04:00.159 Puzzle here, which brings us to the proposed savior, the 76 00:04:00.159 --> 00:04:03.680 thing that's been floating around the physics world for decades, right, 77 00:04:03.840 --> 00:04:04.639 string theory. 78 00:04:04.960 --> 00:04:07.840 String theory is arguably the most famous attempt to fix 79 00:04:07.879 --> 00:04:11.439 those broken equations, because since the dawn of modern physics, 80 00:04:11.759 --> 00:04:16.399 we've always treated the smallest building blocks of matter, you know, quarks, electrons, 81 00:04:16.959 --> 00:04:18.800 as microscopic dots. 82 00:04:18.720 --> 00:04:23.360 Like zero dimensional points with literally no physical size exactly. 83 00:04:23.839 --> 00:04:28.600 And string theory proposes this radical shift. It suggests that 84 00:04:28.639 --> 00:04:32.120 if you were to zoom in, say a billion billion 85 00:04:32.199 --> 00:04:36.839 times smaller than a single proton, a billion billion unimaginable scales. 86 00:04:37.480 --> 00:04:40.319 But if you did, those dots are not actually dots 87 00:04:40.360 --> 00:04:43.839 at all. They're incredibly tiny vibrating one dimensional loops of 88 00:04:43.959 --> 00:04:45.800 energy strings. 89 00:04:45.519 --> 00:04:48.040 And just by swapping out the word dots for strings, 90 00:04:48.120 --> 00:04:49.839 the math suddenly starts behaving. 91 00:04:49.959 --> 00:04:53.040 It does because a string has physical length, right, So 92 00:04:53.079 --> 00:04:56.279 it effectively smears out the interaction over space and time. 93 00:04:56.639 --> 00:05:01.240 And that smearing smooths out those chaotic quantum jitters just 94 00:05:01.399 --> 00:05:06.399 enough to incorporate gravity without triggering those impossible mathematical infinities. 95 00:05:06.480 --> 00:05:08.519 Wow, I mean that sounds like a massive victory, Like 96 00:05:08.560 --> 00:05:10.680 give whoever thought of that a Nobel prize and let's 97 00:05:10.720 --> 00:05:11.040 go home. 98 00:05:11.360 --> 00:05:14.319 If only were that simple as always catch a huge one, 99 00:05:14.519 --> 00:05:17.680 The mathematics of string theory demand a really steep price. 100 00:05:18.199 --> 00:05:20.279 First of all, the equations only work at the universe 101 00:05:20.319 --> 00:05:22.120 has at least ten dimensions ten. 102 00:05:22.240 --> 00:05:25.519 And we only experience four right, three of space, one 103 00:05:25.519 --> 00:05:25.920 of time. 104 00:05:26.360 --> 00:05:29.439 Right, The theory argues, the other six are curled up 105 00:05:29.519 --> 00:05:32.800 so tightly we just can't perceive them. But as you 106 00:05:32.800 --> 00:05:35.839 can imagine, that alone makes a lot of people highly skeptical. 107 00:05:36.319 --> 00:05:39.399 Yeah, ten dimensions is a tough pill to swallow. But 108 00:05:39.920 --> 00:05:42.759 the real problem, the real physical problem, is the proof. 109 00:05:43.040 --> 00:05:43.240 Right. 110 00:05:43.279 --> 00:05:45.920 That's where our milky way sized magnifying glass comes in. 111 00:05:46.040 --> 00:05:50.439 That is the insurmountable hurdle. To physically see something as 112 00:05:50.480 --> 00:05:54.240 infinitesimally small as a string, you have to probe it 113 00:05:54.279 --> 00:05:57.000 with an unimaginably high frequency of energy. 114 00:05:57.000 --> 00:05:59.279 You've got to smash stuff together really really hard. 115 00:05:59.399 --> 00:06:02.879 Exactly, you accelerate particles and smash them together. Right now, 116 00:06:02.920 --> 00:06:05.439 we use the Large Hadron Collider in Switzerland, which is 117 00:06:05.560 --> 00:06:09.399 a ring about seventeen miles in circumference, which is huge, 118 00:06:09.680 --> 00:06:12.959 it is, But to generate enough power to actually detect 119 00:06:13.000 --> 00:06:15.639 a string, you would need to build a particle collider 120 00:06:15.720 --> 00:06:17.120 roughly the size of a galaxy. 121 00:06:17.759 --> 00:06:21.639 Yeah, checking humanity's current infrastructure budget, I'm pretty sure we 122 00:06:21.680 --> 00:06:24.319 cannot afford a galaxy size machine anytime soon. 123 00:06:24.560 --> 00:06:25.120 Not quite. 124 00:06:25.279 --> 00:06:28.959 So we are completely stuck. Like, if you think about it, 125 00:06:29.040 --> 00:06:33.000 we have this beautiful theory that flawlessly unites the two 126 00:06:33.680 --> 00:06:36.720 warring rule books of physics, but it's locked in a 127 00:06:36.800 --> 00:06:40.120 vault that we can never ever physically open. So how 128 00:06:40.120 --> 00:06:43.079 do we even proceed? How can we possibly know if 129 00:06:43.120 --> 00:06:46.759 string theory isn't just an elegant mathematical fantasy you pivot. 130 00:06:47.600 --> 00:06:49.240 I mean, if you can't break through the front door 131 00:06:49.240 --> 00:06:52.120 with physical experiments, you have to find a logical backdoor. 132 00:06:52.759 --> 00:06:55.439 And this is where modern theoretical physicists have recently done 133 00:06:55.439 --> 00:06:59.720 something just brilliant. They decided to revive a classic, almost 134 00:06:59.800 --> 00:07:03.079 for gotten mathematical strategy from the nineteen sixties. It's known 135 00:07:03.120 --> 00:07:04.360 as the bootstrap approach. 136 00:07:04.480 --> 00:07:07.839 The bootstrap approach like the old phrase pulling yourself up 137 00:07:07.839 --> 00:07:09.120 by your bootstrap. 138 00:07:08.720 --> 00:07:11.439 Exactly building something massive out of essentially nothing. 139 00:07:11.639 --> 00:07:13.000 So how does that work in physics? 140 00:07:13.040 --> 00:07:16.480 Well, historically this is fascinating. Back in the nineteen sixties, 141 00:07:16.560 --> 00:07:20.319 prominent physicists, guys like Jeffrey Chew at UC Berkeley and 142 00:07:20.360 --> 00:07:22.240 Stephen Frauschi at Caltech. They were frustrated. 143 00:07:22.360 --> 00:07:23.639 Why what was happening. 144 00:07:23.879 --> 00:07:28.079 Quantum mechanics was just getting incredibly messy. Particle colliders were 145 00:07:28.120 --> 00:07:31.959 spitting out dozens of new, bizarre particles and nobody can 146 00:07:32.000 --> 00:07:35.199 make any sense of the underlying rules. So Chew suggested 147 00:07:35.240 --> 00:07:37.879 they just throw out all their complex models. He wanted 148 00:07:37.879 --> 00:07:39.920 to us start from absolute scratch. 149 00:07:39.759 --> 00:07:42.560 Oh, like, wipe the chalkboard completely clean. 150 00:07:42.720 --> 00:07:46.560 Yes, they adopted the absolute bare minimum universally agreed upon 151 00:07:46.639 --> 00:07:50.360 rules of basic logic and causality, things you just cannot 152 00:07:50.439 --> 00:07:52.439 argue with, and they tried to build up the laws 153 00:07:52.439 --> 00:07:54.600 of physics just from those tiny constraints. 154 00:07:54.720 --> 00:07:55.879 Did it work well? 155 00:07:55.879 --> 00:07:58.439 The problem was, in the nineteen sixties, the sheer computing 156 00:07:58.519 --> 00:08:01.759 power and the mathematical technique needed to actually run those 157 00:08:01.800 --> 00:08:05.519 massive equations that it didn't exist yet. The bootstrap method 158 00:08:05.560 --> 00:08:08.240 became way too complex to manage, and it eventually fell 159 00:08:08.319 --> 00:08:09.399 completely out of fashion. 160 00:08:09.720 --> 00:08:13.920 Ah. Right, but I'm guessing that today, with supercomputers and 161 00:08:14.000 --> 00:08:18.240 better math, modern physicists are dusting off this retro technique. 162 00:08:18.319 --> 00:08:21.079 What's fascinating here is how powerful this method has become. 163 00:08:21.120 --> 00:08:24.279 In the modern era, physicists like Clifford Chung and Grant 164 00:08:24.319 --> 00:08:27.519 Remen decided to apply that old bootstrap philosophy to the 165 00:08:27.600 --> 00:08:29.720 ultimate problem, quantum gravity. 166 00:08:30.000 --> 00:08:33.240 So instead of assuming string theory is real and trying 167 00:08:33.279 --> 00:08:36.240 to prove it, they just started with that blank slate exactly. 168 00:08:36.320 --> 00:08:39.879 They adopted just two basic rules about how energy and 169 00:08:39.919 --> 00:08:43.679 particles should behave, and they let the mathematics dictate what 170 00:08:43.799 --> 00:08:45.080 the universe must look like. 171 00:08:45.240 --> 00:08:47.559 Okay, I have an analogy for this. Tell me if 172 00:08:47.559 --> 00:08:49.399 I'm on the right track here, go for it. This 173 00:08:49.480 --> 00:08:52.960 sounds exactly like a Pseudoku puzzle. Oh. I like that, right, 174 00:08:53.440 --> 00:08:56.080 Because when you sit down with a blank Sudoku grid, 175 00:08:56.200 --> 00:08:58.720 you don't guess the final picture. You don't just start 176 00:08:58.759 --> 00:09:01.639 throwing numbers in ran because you think they look nice. 177 00:09:02.039 --> 00:09:05.279 You only have a few fundamental rules, right numbers one 178 00:09:05.320 --> 00:09:07.799 through nine. No repeats in a row, no repeats in 179 00:09:07.840 --> 00:09:09.360 a column, no repeats in a box. 180 00:09:09.480 --> 00:09:11.320 That is a perfect way to visualize it. 181 00:09:11.519 --> 00:09:13.879 And the magic of a Sudoku puzzle is that if 182 00:09:13.919 --> 00:09:18.240 you follow those basic rules strictly mathematically, there is only 183 00:09:18.360 --> 00:09:21.200 one unique solution that can possibly emerge at the end. 184 00:09:21.320 --> 00:09:24.279 You don't force the outcome at all. The constraints force 185 00:09:24.360 --> 00:09:24.879 the outcome. 186 00:09:25.080 --> 00:09:28.639 That's exactly the same logic they used. These physicists wanted 187 00:09:28.639 --> 00:09:31.360 to set up the cosmic Sudoku grid. They need to 188 00:09:31.399 --> 00:09:34.799 find the absolute minimum constraints required for the universe to 189 00:09:34.840 --> 00:09:38.519 function without tearing itself apart with mathematical infinities. 190 00:09:38.600 --> 00:09:40.799 Okay, so we need to look at the specific rules 191 00:09:40.840 --> 00:09:43.240 they plugged into this grid. What is rule number one? 192 00:09:43.399 --> 00:09:46.840 Rule number one is something they call ultrasoftness. And to 193 00:09:46.919 --> 00:09:49.519 understand why this rule is necessary, we have to talk 194 00:09:49.559 --> 00:09:51.799 about a concept called the plank scale. 195 00:09:52.039 --> 00:09:54.360 Let's translate that. What does the plank scale look like 196 00:09:54.480 --> 00:09:55.879 in plain English. 197 00:09:56.320 --> 00:09:59.679 It is the ultimate extreme of physics. It's an energy 198 00:09:59.759 --> 00:10:03.159 level roughly nineteen orders of magnitude greater than the mass 199 00:10:03.159 --> 00:10:03.919 of a single. 200 00:10:03.679 --> 00:10:06.039 Proton, which is hard to picture. 201 00:10:06.080 --> 00:10:08.279 Right, So to give you an intumitive sense of that scale, 202 00:10:08.720 --> 00:10:11.480 imagine taking the explosive energy of a full tank of 203 00:10:11.559 --> 00:10:14.919 jet fuel, okay, and compressing all of that immense power 204 00:10:15.360 --> 00:10:18.480 down into a space the size of a single subatomic particle. 205 00:10:18.679 --> 00:10:22.919 Oh wow, that is an incomprehensible level of density and heat. 206 00:10:23.200 --> 00:10:27.240 It is. And at that extreme scale, general relativity breaks. 207 00:10:27.759 --> 00:10:31.159 The gravitational pull between particles becomes so intense that if 208 00:10:31.200 --> 00:10:35.399 they were to actually collide, the resulting mathematical probability equations 209 00:10:35.679 --> 00:10:37.639 rock it straight to infinity. 210 00:10:37.240 --> 00:10:38.720 The fatal error recidence. 211 00:10:38.840 --> 00:10:43.120 Right, the math says, the universe breaks. So to fix 212 00:10:43.159 --> 00:10:47.720 this on their blank slate, the physicists introduced ultrasoftness. They 213 00:10:47.759 --> 00:10:51.120 assumed that for reality to exist, nature must have a 214 00:10:51.159 --> 00:10:54.399 mechanism that softens these interactions at ultimate extremes. 215 00:10:54.600 --> 00:10:56.840 Wait, I gotta stop you there. How does an interaction 216 00:10:57.000 --> 00:10:59.519 soften when you have that much energy involved? Like if 217 00:10:59.559 --> 00:11:01.799 two things are hurtling toward each other with the energy 218 00:11:01.840 --> 00:11:04.320 of a jet engine. How do they not create a 219 00:11:04.360 --> 00:11:05.600 catastrophic crash. 220 00:11:05.679 --> 00:11:07.759 It's weird, I know. Think of it less like physical 221 00:11:07.759 --> 00:11:10.759 objects colliding and more like sound waves or water waves. 222 00:11:11.279 --> 00:11:14.000 If two massive ocean waves crash directly into each other, 223 00:11:14.159 --> 00:11:17.559 you get a violent, localized splash. Right, that's our mathematical infinity. 224 00:11:18.200 --> 00:11:22.480 But ultrasoftness suggests that at the absolute highest energy extremes, 225 00:11:22.720 --> 00:11:25.799 particles act more like ripples in a pond. As their 226 00:11:25.919 --> 00:11:28.080 energy increases, they start to spread. 227 00:11:27.759 --> 00:11:28.720 Out, spread out. 228 00:11:28.879 --> 00:11:32.039 Yeah, when they meet, they just glide through one another's frequencies. 229 00:11:32.360 --> 00:11:36.559 They disperse the energy smoothly instead of creating a localized explosion. 230 00:11:36.759 --> 00:11:39.840 Oh okay, here's where it gets really interesting. So it's 231 00:11:39.879 --> 00:11:42.840 like two cars speeding toward each other on a highway. 232 00:11:43.559 --> 00:11:47.440 Normally you'd expect a catastrophic crash, which is our infinite math, 233 00:11:48.080 --> 00:11:51.879 but at extremely high speeds, instead of crashing, they decide 234 00:11:52.039 --> 00:11:54.720 they just don't want to interact. They turn into ghosts 235 00:11:54.720 --> 00:11:56.879 and pass reely right through one another. 236 00:11:57.120 --> 00:11:59.440 That's a great way to picture it. By requiring the 237 00:11:59.480 --> 00:12:03.360 math to follow this rule of ultrasoftness, the interaction probabilities 238 00:12:03.399 --> 00:12:07.480 drop swiftly as energy rises. The feedback loop of infinite 239 00:12:07.600 --> 00:12:10.279 energies is prevented and reality holds together. 240 00:12:10.559 --> 00:12:12.879 And the beauty of this is they didn't assume strings 241 00:12:12.919 --> 00:12:16.080 were causing this ghost like smearing. They just said, look, 242 00:12:16.159 --> 00:12:18.720 if the math is going to work, this softening effect 243 00:12:18.799 --> 00:12:20.879 has to happen regardless of what's causing it. 244 00:12:21.399 --> 00:12:21.919 Precisely. 245 00:12:22.000 --> 00:12:23.720 Okay, that's rule one. What about rule two? 246 00:12:23.919 --> 00:12:28.080 Rule two deals with what physicists call minimal zeros. Now, 247 00:12:28.120 --> 00:12:30.039 this one gets a little deep into the mechanics of 248 00:12:30.039 --> 00:12:32.759 something called scattering amplitudes. 249 00:12:32.080 --> 00:12:34.080 Which means what exactly. 250 00:12:33.879 --> 00:12:37.120 It's just the technical term for calculating the angles, momentum, 251 00:12:37.120 --> 00:12:39.399 and spin of particles when they bounce off one another. 252 00:12:39.480 --> 00:12:41.919 Got it, the mechanics of a sub atomic. 253 00:12:41.519 --> 00:12:45.840 Car crash exactly. Within these calculations there are very specific 254 00:12:45.879 --> 00:12:49.600 collision setups, what we call kinematic points. These are exact 255 00:12:49.639 --> 00:12:53.399 angles and speeds where the math dictates the particles must 256 00:12:53.440 --> 00:12:57.000 not interact. They must simply bounce away or pass by 257 00:12:57.480 --> 00:12:59.120 without exchanging any energy. 258 00:12:59.320 --> 00:13:00.840 Like mathmat called dead zones. 259 00:13:00.960 --> 00:13:02.759 Yes, they're called zeros. 260 00:13:02.759 --> 00:13:05.440 But why does the universe need dead zones where nothing happens? 261 00:13:05.639 --> 00:13:09.360 Because if particles interacted and exchange energy at absolutely every 262 00:13:09.399 --> 00:13:12.960 possible angle in every possible speed. The sheer volume of 263 00:13:13.000 --> 00:13:16.519 those interactions would again trigger a runaway feedback loop. 264 00:13:16.600 --> 00:13:18.600 Ah, the infinities come back right. 265 00:13:18.679 --> 00:13:22.000 The math requires these zeros to act as safety valves, so. 266 00:13:22.080 --> 00:13:27.039 Minimal zeros is basically like designing a massive, complex highway system. 267 00:13:27.279 --> 00:13:30.080 If you have cars interacting at every single intersection, you 268 00:13:30.120 --> 00:13:32.759 get infinite gridlock. You need red lights. You need points 269 00:13:32.759 --> 00:13:35.519 where cars are forced not to interact. I love that, yes, 270 00:13:35.879 --> 00:13:38.440 and the rule of minimal zero says you want the 271 00:13:38.480 --> 00:13:41.639 absolute fewest number of red lights possible to keep the 272 00:13:41.679 --> 00:13:44.039 traffic flowing smoothly without a pile up. 273 00:13:44.440 --> 00:13:48.759 That is a phenomenal analogy. You demand the strict mathematical 274 00:13:48.799 --> 00:13:51.679 minimum of these non interaction points required for the whole 275 00:13:51.799 --> 00:13:54.679 system to hold together. You don't want an infinite number 276 00:13:54.679 --> 00:13:57.159 of red lights because then nothing moves. You want the 277 00:13:57.200 --> 00:13:57.879 bare minimum. 278 00:13:57.919 --> 00:14:02.120 Okay, the Sidoku grid is set. We have Rule one ultrasoftness. 279 00:14:02.720 --> 00:14:05.919 Particles must smear out or turn into ghosts and soften 280 00:14:05.960 --> 00:14:08.679 their interactions at crazy high energies to avoid an infinite 281 00:14:08.679 --> 00:14:13.519 crash check and rule two minimal zeros. The universe must 282 00:14:13.519 --> 00:14:16.519 operate with the absolute fewest number of mathematical red lights 283 00:14:16.600 --> 00:14:19.559 or dead zones allowed. That's it, two basic rules of 284 00:14:19.600 --> 00:14:21.000 logic and traffic management. 285 00:14:21.399 --> 00:14:24.960 Just those two. The researchers deliberately used. No assumptions about 286 00:14:24.960 --> 00:14:28.919 extra dimensions, no assumptions about microscopic vibrating. 287 00:14:28.480 --> 00:14:30.240 Loops, just a completely blank slate. 288 00:14:30.480 --> 00:14:34.159 Right. They took those two unbendable rules and they let 289 00:14:34.200 --> 00:14:36.639 the mathematical engines run to see what kind of universe 290 00:14:36.639 --> 00:14:41.000 would naturally emerge. They mapped out every possible mathematical function 291 00:14:41.080 --> 00:14:44.360 that could satisfy both ultrasoftness and minimal zeros. 292 00:14:44.639 --> 00:14:47.679 And out of all the infinite possibilities of how the 293 00:14:47.759 --> 00:14:52.159 universe could be structured, how many valid mathematical solutions did 294 00:14:52.200 --> 00:14:53.159 they actually find? 295 00:14:53.399 --> 00:14:55.279 They found exactly one, just one. 296 00:14:55.440 --> 00:14:57.399 The Sudoku puzzle solved itself. 297 00:14:57.679 --> 00:15:02.399 Only one unique mathematical function satisfied both of those logical constraints. 298 00:15:02.879 --> 00:15:05.159 And this is really the climax of the whole endeavor, 299 00:15:05.360 --> 00:15:09.279 because that singular mathematical function was not some random string 300 00:15:09.360 --> 00:15:12.639 of new numbers. It was the exact defining formula of 301 00:15:12.679 --> 00:15:13.399 string theory. 302 00:15:13.600 --> 00:15:14.039 No way. 303 00:15:14.240 --> 00:15:16.960 Yes, as Clifford Chung put it, they started with basic 304 00:15:17.000 --> 00:15:18.799 logic and the strings just fell out. 305 00:15:18.759 --> 00:15:20.879 That gives me literal chills. The strings just fell out. 306 00:15:20.879 --> 00:15:23.720 You don't even go looking for string theory. Pure logic 307 00:15:23.799 --> 00:15:26.279 traps the truth in a corner, and string theory is 308 00:15:26.320 --> 00:15:27.960 the only thing left standing in the room. 309 00:15:28.080 --> 00:15:31.559 It's incredible and it wasn't just a vague approximation either. 310 00:15:32.000 --> 00:15:35.679 The solution that emerged from the bootstrap math perfectly matched 311 00:15:35.720 --> 00:15:37.360 something known as the string spectrum. 312 00:15:37.440 --> 00:15:38.480 The string spectrum. 313 00:15:38.600 --> 00:15:41.600 Yeah. To appreciate this, we have to look back again 314 00:15:41.679 --> 00:15:45.360 to the late nineteen sixties to an Italian physicist named 315 00:15:45.399 --> 00:15:46.639 gabrielle Vinzziano. 316 00:15:46.879 --> 00:15:48.759 Right, I know this one. He was looking at the 317 00:15:48.799 --> 00:15:51.559 messy data coming out of particle colliders at CERN. 318 00:15:51.840 --> 00:15:55.320 He was Article colliders back then were spitting out a 319 00:15:55.320 --> 00:15:59.960 confusing spray of subatomic debris, just particles of all different maps, 320 00:16:00.000 --> 00:16:04.759 masses and spins. It looked like chaotic junk. But Vineziano 321 00:16:04.799 --> 00:16:08.240 managed to write down a mathematical formula that described all 322 00:16:08.320 --> 00:16:09.840 these varying masses. 323 00:16:09.519 --> 00:16:10.480 And what did it look like. 324 00:16:10.960 --> 00:16:14.799 His formula revealed a beautiful infinite tower or a ladder 325 00:16:15.200 --> 00:16:18.720 of massive spinning particles where the mass and spin increased 326 00:16:18.759 --> 00:16:20.960 in very discrete, orderly steps. 327 00:16:20.879 --> 00:16:23.000 Like climbing the rungs of a ladder. But what was 328 00:16:23.039 --> 00:16:24.600 actually causing those steps? 329 00:16:24.679 --> 00:16:27.279 Well, a the time, Benenciano didn't know. But a few 330 00:16:27.320 --> 00:16:30.279 years later other physicists looked at his formula and realized 331 00:16:30.320 --> 00:16:34.080 that this mysterious tower of particles corresponded perfectly to the 332 00:16:34.120 --> 00:16:36.159 harmonic series of a vibrating string. 333 00:16:36.399 --> 00:16:38.759 Oh, I see, So it's literally like plucking a guitar 334 00:16:38.840 --> 00:16:43.440 string or a violin string. You don't just get static noise, 335 00:16:43.480 --> 00:16:45.840 You get a fundamental bass note, and then you get 336 00:16:45.840 --> 00:16:50.840 a distinct mathematical series of overtones or harmonics. Exactly are 337 00:16:50.879 --> 00:16:54.720 you saying? Those different microscopic harmonics are the different subatomic particles. 338 00:16:54.919 --> 00:16:57.799 That is the core beauty of the theory. A single 339 00:16:58.039 --> 00:17:02.960 fundamental entity of vibrating microscopic string can create the entire 340 00:17:03.080 --> 00:17:07.319 zoo of subatomic particles just by changing its tune. An 341 00:17:07.319 --> 00:17:11.119 open ended string vibrating in its fundamental mode produces the 342 00:17:11.160 --> 00:17:13.920 mass and spin of a photon, the particle of light. 343 00:17:14.000 --> 00:17:16.400 Wait, so if a different vibration gives you a different particle, 344 00:17:17.319 --> 00:17:19.599 what vibration gives you gravity? Ah? 345 00:17:19.720 --> 00:17:21.759 If the string is a closed loop, like a tiny 346 00:17:21.799 --> 00:17:25.000 rubber band, and it vibrates in a specific mode, the 347 00:17:25.000 --> 00:17:28.559 math perfectly describes the graviton. The graviton, yeah, the theoretical 348 00:17:28.599 --> 00:17:30.519 particle that carries the force of gravity. It is built 349 00:17:30.519 --> 00:17:32.359 in from the start. That was the huge breakthrough in 350 00:17:32.400 --> 00:17:36.400 the nineteen seventies. String theory naturally contained gravity operating smoothly 351 00:17:36.440 --> 00:17:38.680 at the quantum level without throwing infinite errors. 352 00:17:38.960 --> 00:17:42.359 So, bringing it back to this new research, by just 353 00:17:42.400 --> 00:17:44.839 applying rule one and rule two to a blank slate, 354 00:17:45.359 --> 00:17:49.599 this infinite tower of musical particles just naturally emerged from 355 00:17:49.640 --> 00:17:50.920 the equations. 356 00:17:50.440 --> 00:17:54.920 Every single bit of it, the precise interaction strengths, the harmonics, 357 00:17:55.000 --> 00:17:58.319 the behavior of gravity, all of it emerged automatically as 358 00:17:58.359 --> 00:18:02.400 the only logical way to satisfy ultrasoftness and minimal zeros. 359 00:18:02.480 --> 00:18:05.279 Okay, I have to ask the crucial skeptical question here. 360 00:18:05.319 --> 00:18:07.759 Let me push back for a second. Do if the 361 00:18:07.799 --> 00:18:11.640 math leads to exactly one solution, and that solution perfectly 362 00:18:11.680 --> 00:18:15.400 mirrors string theory, does this mean string theory is officially 363 00:18:15.440 --> 00:18:19.079 a fact? Like have we bypassed the galaxy sized collider 364 00:18:19.119 --> 00:18:21.160 and proven it using just math? 365 00:18:21.559 --> 00:18:23.759 It is vital to make a distinction here. No, this 366 00:18:23.880 --> 00:18:25.960 does not mean string theory is officially proven as a 367 00:18:25.960 --> 00:18:29.359 physical experimental fact we still have not directly observed to 368 00:18:29.400 --> 00:18:32.599 string science fundamentally relies on physical. 369 00:18:32.359 --> 00:18:34.680 Observation, So we can't throw a parade just yet. 370 00:18:34.880 --> 00:18:38.440 Not a parade, no, but maybe a quiet, deeply profound 371 00:18:38.440 --> 00:18:42.319 celebration in the theoretical physics department, because what this provides 372 00:18:42.400 --> 00:18:46.519 is incredibly robust theoretical proof. Before this, you could argue 373 00:18:46.519 --> 00:18:49.440 that string theory was just one of many possible arbitrary 374 00:18:49.440 --> 00:18:52.200 ways to fix the math. But this research shows that 375 00:18:52.240 --> 00:18:56.480 if you accept two highly logical, almost unavoidable constricts about 376 00:18:56.519 --> 00:18:59.720 how high energy particles behave, the math doesn't yield an 377 00:18:59.759 --> 00:19:03.720 in definite number of garbage solutions. It yields one deeply 378 00:19:03.799 --> 00:19:04.839 elegant framework. 379 00:19:05.599 --> 00:19:08.440 So what does this all mean when we step back 380 00:19:08.480 --> 00:19:11.839 from the massive equations, plank scales and the quantum jitter. 381 00:19:12.680 --> 00:19:15.240 What does this tell us about the fundamental nature of reality? 382 00:19:15.559 --> 00:19:17.960 Well, if we connect this to the bigger picture, it 383 00:19:18.000 --> 00:19:21.279 implies a universe that is far less ratrary than we thought. 384 00:19:22.079 --> 00:19:25.480 As prominent physicists have pointed out, this boostrap approach narrows 385 00:19:25.519 --> 00:19:27.319 the playing field of reality. 386 00:19:27.000 --> 00:19:28.559 Narrowing it down just one option. 387 00:19:28.880 --> 00:19:31.160 Right, It shows us that the universe isn't a random 388 00:19:31.160 --> 00:19:34.680 collection of laws bolted together. It strongly implies that the 389 00:19:34.680 --> 00:19:38.200 fundamental nature of existence is tightly constrained by pure logic. 390 00:19:38.599 --> 00:19:42.319 So, to everyone listening to this right now, the universe 391 00:19:42.400 --> 00:19:45.279 might not be random at all. The puzzle of reality 392 00:19:45.400 --> 00:19:49.759 might only have one valid configuration. The pieces literally cannot 393 00:19:49.759 --> 00:19:53.319 fit together any other way without breaking the universe. You 394 00:19:53.359 --> 00:19:56.200 don't necessarily need to see everything to prove it exists. 395 00:19:56.720 --> 00:19:59.759 Sometimes pure logic traps the truth in a corner. 396 00:19:59.480 --> 00:20:02.960 Precisely, which leaves us with a truly fascinating and maybe 397 00:20:03.000 --> 00:20:06.000 slightly unnerving puzzle to ponder on our own. 398 00:20:06.119 --> 00:20:07.160 Oh, what's that? 399 00:20:07.680 --> 00:20:10.759 If this cosmic sudoku puzzle proves that string theory is 400 00:20:10.799 --> 00:20:14.319 the only possible answer based on these two basic assumptions, 401 00:20:15.000 --> 00:20:17.799