WEBVTT - What is membrane theory? 0:00:00.080 --> 0:00:02.960 If you love iPhone, you'll love Apple Card. It's the 0:00:03.040 --> 0:00:06.920 credit card designed for iPhone. It gives you unlimited daily 0:00:07.040 --> 0:00:10.000 cash back that can earn four point four zero percent 0:00:10.160 --> 0:00:12.960 annual percentage yield. When you open a high Yield savings 0:00:13.000 --> 0:00:16.280 account through Apple Card, apply for Applecard in the wallet 0:00:16.280 --> 0:00:19.520 app subject to credit approval. Savings is available to Apple 0:00:19.560 --> 0:00:22.800 Card owners subject to eligibility. Apple Card and Savings by 0:00:22.840 --> 0:00:26.120 Goldman Sachs Bank USA, Salt Lake City Branch Member FDIC 0:00:26.520 --> 0:00:29.280 terms and more at applecard dot com. When you pop 0:00:29.320 --> 0:00:31.240 a piece of cheese into your mouth, you're probably not 0:00:31.360 --> 0:00:34.280 thinking about the environmental impact. 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Cards issued by JP 0:01:52.120 --> 0:01:55.760 Morgan Chase Bank NA Member FDIC subject to credit approval. 0:01:55.840 --> 0:01:57.160 Offers subject to change. 0:01:57.240 --> 0:01:58.000 Terms apply. 0:02:06.240 --> 0:02:08.800 Hey Daniel, have you guys figured out what's inside a 0:02:08.840 --> 0:02:09.400 black hole? 0:02:09.480 --> 0:02:12.800 Yet unfortunately not still pretty confused. 0:02:13.200 --> 0:02:15.800 Okay, it sounds like you guys need to go back 0:02:15.840 --> 0:02:18.200 to the drawing board get some new ideas. 0:02:18.840 --> 0:02:21.560 I know, but like from where the smartest people on 0:02:21.600 --> 0:02:24.800 the planet have been stuck in this question for literally decades. 0:02:25.160 --> 0:02:27.760 See that is where you are going wrong. You are 0:02:27.800 --> 0:02:32.600 looking to the smart people. If you need wacky, crazy ideas, 0:02:32.639 --> 0:02:35.240 you need to ask the wacky crazy people like me. 0:02:37.639 --> 0:02:39.520 You're saying we should go to the insane asylum and 0:02:39.560 --> 0:02:41.800 ask people what they think is inside a black hole. 0:02:42.040 --> 0:02:44.359 I think that they could come up with some good ideas. 0:02:44.440 --> 0:02:47.120 They might be insane enough in the membrane to figure 0:02:47.160 --> 0:02:47.440 it out. 0:02:49.480 --> 0:03:07.880 Insane in the brain. Hi, I'm Daniel. I'm a particle 0:03:07.919 --> 0:03:10.760 physicist and a professor at UC Irvine. And if you 0:03:10.800 --> 0:03:13.640 didn't get my Cypress Hill reference, you're officially young. 0:03:14.360 --> 0:03:20.320 I am Katie. I am not a physicist. I like animals, though, 0:03:20.800 --> 0:03:25.080 and I like the universe. And I got that reference. 0:03:25.000 --> 0:03:27.000 Because you're insane in the membrane. 0:03:26.639 --> 0:03:30.240 Exactly, just the membrane, though the rest of me is 0:03:30.440 --> 0:03:31.720 perfectly sane. 0:03:33.240 --> 0:03:36.320 And Welcome to the podcast. Daniel and Jorge explain the 0:03:36.400 --> 0:03:39.040 universe in which we do our best to bring this 0:03:39.200 --> 0:03:43.120 insane universe into your brain. We try to make it 0:03:43.160 --> 0:03:46.000 all make sense, from the tiniest little quantum particles to 0:03:46.040 --> 0:03:50.840 the hugest swirling accretion disks surrounding super massive black holes. 0:03:51.240 --> 0:03:55.200 We have this hunch that maybe the universe is understandable, 0:03:55.560 --> 0:03:58.800 that it's a big mathematical puzzle, that we can eventually 0:03:59.000 --> 0:04:01.480 figure it out if we put all of our brains 0:04:01.480 --> 0:04:04.760 and membranes together, and our goal on this podcast is 0:04:04.800 --> 0:04:06.120 to explain all of it to you. 0:04:06.880 --> 0:04:10.600 Now, that's another song, super Massive black Hole. I think 0:04:10.760 --> 0:04:15.560 news soundtrack to that really sort of indie movie called Twilight. 0:04:17.600 --> 0:04:19.479 Are you sure that wasn't part of the hip hop 0:04:19.520 --> 0:04:21.520 wars in the nineties, super Massive black Hole. 0:04:22.760 --> 0:04:26.880 I couldn't say. In the nineties, I was not cool 0:04:27.000 --> 0:04:27.479 enough to know. 0:04:27.920 --> 0:04:30.720 Well, you know, maybe there are some secrets in music 0:04:30.880 --> 0:04:33.760 that can help us crack the mysteries of the universe, 0:04:34.040 --> 0:04:36.719 because you know, some people say the universe is musical 0:04:36.760 --> 0:04:39.960 and there's a connection between music and mathematics, right, So 0:04:40.000 --> 0:04:42.120 maybe we have been looking in the wrong places. 0:04:42.520 --> 0:04:45.760 Yeah, Like I've heard this in terms of string theory, 0:04:45.800 --> 0:04:49.120 where strings aren't you know, they're not like violin strings, 0:04:49.160 --> 0:04:54.400 but it's something about some like either vibration or pattern. Honestly, 0:04:54.960 --> 0:04:59.240 I do not understand it, but you know, I think 0:04:59.279 --> 0:05:02.800 that is interesting saying that there is the idea that 0:05:02.920 --> 0:05:06.080 a lot of the mysteries of the universe could be 0:05:06.160 --> 0:05:10.880 about certain frequencies or patterns, which is also what is 0:05:10.960 --> 0:05:14.800 the major components of music exactly. 0:05:14.839 --> 0:05:17.360 Although if you listen to Terrence Howard on Joe Rogan, 0:05:17.560 --> 0:05:19.400 it's all frequencies. 0:05:18.760 --> 0:05:20.440 Man, is all frequencies? 0:05:20.480 --> 0:05:20.800 Man? 0:05:20.960 --> 0:05:23.800 Why am I not on Joe Rogan? See, I just 0:05:24.240 --> 0:05:25.280 can say that too. 0:05:25.680 --> 0:05:29.000 I can because you believe that one times one equals one, 0:05:29.120 --> 0:05:32.039 and Terrence Howard proves that it equals to and wow, 0:05:32.400 --> 0:05:35.120 that's why you're just not mathematically qualified. 0:05:34.600 --> 0:05:34.760 To be. 0:05:36.320 --> 0:05:38.839 I just can't think outside of the box enough to 0:05:38.920 --> 0:05:41.880 not do mouth good exactly. 0:05:42.240 --> 0:05:45.080 But we are fascinated by the mysteries of the universe. 0:05:45.120 --> 0:05:47.680 We do think that there are mathematical solutions to them. 0:05:48.000 --> 0:05:51.239 Maybe they are encoded in the sonatas of Mozart. Maybe 0:05:51.279 --> 0:05:53.800 the engineers are right that it's all vibrations all the 0:05:53.839 --> 0:05:56.960 way down. But we hope that there is an explanation. 0:05:57.279 --> 0:05:58.760 And one of the biggest things that we need an 0:05:58.800 --> 0:06:01.640 explanation for is how to think about the universe on 0:06:01.680 --> 0:06:05.280 the smallest scales. What happens when things get really, really 0:06:05.320 --> 0:06:09.040 dense and really really tiny. One of the biggest puzzles 0:06:09.080 --> 0:06:11.920 in modern physics is how to put together the two 0:06:12.000 --> 0:06:16.680 pillars of our understanding of the universe, relativity and quantum mechanics. 0:06:17.000 --> 0:06:19.160 We've been banging our heads against this for almost one 0:06:19.200 --> 0:06:23.520 hundred years, basically since we've had relativity and quantum mechanics 0:06:23.680 --> 0:06:27.840 and realize that they are fundamentally incompatible at the smallest scale, 0:06:28.360 --> 0:06:30.200 and we've been trying to figure this out. And today 0:06:30.200 --> 0:06:33.479 on the podcast, we'll be exploring yet another attempt to 0:06:33.800 --> 0:06:38.680 unify relativity and quantum mechanics. So on the podcast today 0:06:38.720 --> 0:06:47.320 we'll be answering the question what is membrane theory? 0:06:48.080 --> 0:06:51.880 Okay, as a biology nerd, I'm pretty sure I can 0:06:52.000 --> 0:06:57.280 answer this. A membrane is a semi permeable barrier. So 0:06:58.080 --> 0:07:01.719 I did it. I solved it. Congratulations to me. 0:07:02.720 --> 0:07:05.640 What about the audio barrier between us and the listeners 0:07:06.000 --> 0:07:08.359 the ideas from our brains and that their brains have 0:07:08.480 --> 0:07:10.760 we permeated a membrane? I? 0:07:11.240 --> 0:07:15.920 Yes, why not? I don't know enough about audio engineering 0:07:15.960 --> 0:07:19.560 to say no or philosophy, So I'm gonna say yes. 0:07:19.640 --> 0:07:25.240 We're like salt ions through the airwaves, permeating the membrane, 0:07:25.840 --> 0:07:28.080 so hopefully you can reach homeostasis. 0:07:30.600 --> 0:07:33.040 So I'm not surprised that when you heard this phrase 0:07:33.160 --> 0:07:37.520 you thought of cellular membranes divisions between solutions. You want 0:07:37.560 --> 0:07:40.160 to keep osmosis from like moving all these bits of 0:07:40.200 --> 0:07:43.280 salt over here, or using fats to keep that over there. 0:07:43.800 --> 0:07:47.040 But it's not just in biology that we have membranes. 0:07:47.080 --> 0:07:50.560 It turns out that they are fundamental concept in theories 0:07:50.600 --> 0:07:53.920 of quantum gravity. But before we dig into that, I 0:07:53.960 --> 0:07:56.240 was curious what everybody else out there thought when they 0:07:56.280 --> 0:08:00.280 heard membrane theory, So, as usual, I asked our andre 0:08:00.440 --> 0:08:04.120 of volunteers to speculate on the question without the opportunity 0:08:04.160 --> 0:08:07.400 to use Google. So if you would like to join 0:08:07.480 --> 0:08:09.800 this group of volunteers in the future, please don't be shy. 0:08:09.880 --> 0:08:13.760 Write me to questions at Danielandjorge dot com. We all 0:08:13.800 --> 0:08:17.160 want to hear what you have to say. In the meantime, 0:08:17.280 --> 0:08:20.360 check out these answers from listeners. What do you think 0:08:20.560 --> 0:08:24.520 membrane theory is? Here's what people had to say that's 0:08:24.560 --> 0:08:25.920 the first time I'm hearing golf it. 0:08:26.200 --> 0:08:28.680 But if I had to guess membranes, the function of 0:08:28.720 --> 0:08:32.160 the memoranes are to pass on stuff in one direction 0:08:32.280 --> 0:08:35.480 and other stuff not in the other direction. So maybe 0:08:35.480 --> 0:08:41.800 we're talking about it's a mechanism about particle coexistence through 0:08:41.960 --> 0:08:43.640 a wall of things, something like that. 0:08:43.840 --> 0:08:45.520 Just I guess what comes to mind for me on 0:08:45.520 --> 0:08:48.320 that one is that it's something that you use to 0:08:48.360 --> 0:08:50.720 separate things, like in a fuel cell car. You know, 0:08:50.840 --> 0:08:53.559 you separate components and you make energy. Maybe it's like 0:08:53.600 --> 0:08:55.680 a desalination thing where you take salt. 0:08:55.480 --> 0:08:56.000 Out of water. 0:08:56.440 --> 0:08:59.079 So maybe there's some membrane here in the universe that's 0:08:59.160 --> 0:09:00.840 uh in that in space. 0:09:01.720 --> 0:09:05.320 I'm guessing membrane theory has to do with the outside 0:09:05.320 --> 0:09:10.240 of a cell. Maybe how the membrane, you know, protects 0:09:10.280 --> 0:09:14.240 the core of the cell and how it stays intact. 0:09:14.720 --> 0:09:16.640 I think it has to do with string theory. There 0:09:16.679 --> 0:09:19.120 are strings that vibrate in there one dimension, and I 0:09:19.120 --> 0:09:20.600 think a membrane is a. 0:09:22.000 --> 0:09:24.280 Something similar that can have more than one dimension. 0:09:25.120 --> 0:09:31.079 See, I'm I'm definitely with the theory that everything is 0:09:31.160 --> 0:09:33.840 a cell. If you look at the universe, it's just 0:09:33.880 --> 0:09:38.600 a giant body for some kind of huge animal. You know, 0:09:39.000 --> 0:09:42.760 it makes sense, right, you're saying the universe is alive. Yeah, 0:09:42.840 --> 0:09:45.840 it's a big maybe a giant cat. I don't know, 0:09:45.920 --> 0:09:49.120 have you ever looked at like a black cat? Right, 0:09:49.320 --> 0:09:53.520 it's it kind of has that sort of quantum mechanics 0:09:53.559 --> 0:09:58.240 and general relativity paradox. Right, it's like a fluid, it's 0:09:58.240 --> 0:10:01.160 a solid, it's sweet and le and then it bites you. 0:10:01.400 --> 0:10:04.240 So yeah, I think the universe could be a giant cat. 0:10:04.400 --> 0:10:07.080 And when you get down to the tiniest components there 0:10:07.120 --> 0:10:09.520 cells and yeah, it's been solved. 0:10:09.679 --> 0:10:13.240 You're welcome and we're done, Thank you very much. Physics 0:10:13.360 --> 0:10:16.199 is over. Katie wins all of the Nobel prices. 0:10:16.400 --> 0:10:16.559 Yay. 0:10:17.160 --> 0:10:20.520 Well, we're definitely hearing from listeners the connection to biology, 0:10:20.559 --> 0:10:23.120 which makes a lot of sense, and the idea of 0:10:23.240 --> 0:10:28.320 having two dimensional surfaces or even connections to string theory. 0:10:28.400 --> 0:10:29.920 So there's a lot of good stuff in here that 0:10:29.920 --> 0:10:32.840 we're going to dig into and explain in this episode. 0:10:32.960 --> 0:10:35.960 But a plus to all the listeners. 0:10:35.520 --> 0:10:38.200 I mean, I would assume that, yes, it's probably not 0:10:38.400 --> 0:10:42.280 like a cellular membrane, but if we're talking about a membrane. 0:10:42.800 --> 0:10:47.640 I would guess it is some kind of barrier through 0:10:47.720 --> 0:10:53.000 which certain physics transactions can occur. But that would be 0:10:53.040 --> 0:10:53.760 my guess. 0:10:54.720 --> 0:10:57.839 Is this whole podcast a physics transaction? We are taking 0:10:57.880 --> 0:11:00.480 your time and exchanging it for knowledge, is like a 0:11:00.520 --> 0:11:02.120 physics transaction, you know what? 0:11:02.520 --> 0:11:05.400 That's pretty good. I think I'm wondering about the exchange 0:11:05.440 --> 0:11:08.480 rate though, because that's that's the real issue. 0:11:08.760 --> 0:11:10.960 Yeah, I think we're too high on the jokes permitt 0:11:10.960 --> 0:11:12.720 it and too low and the physics permitted so far. 0:11:12.800 --> 0:11:14.080 Let's try to flip that right now. 0:11:14.920 --> 0:11:17.400 All right, well, okay, let me have it, Like, what's 0:11:17.480 --> 0:11:19.040 going on with this membrane theory? 0:11:19.280 --> 0:11:21.800 So membrane theory is an attempt to crack the puzzle 0:11:22.040 --> 0:11:25.160 of quantum gravity. So let's start with that. What is 0:11:25.200 --> 0:11:27.440 the puzzle of quantum gravity? Why do we want to 0:11:27.480 --> 0:11:29.800 crack it? What is the issue? Why are all the 0:11:29.840 --> 0:11:31.960 smart people on the planet thinking they need to go 0:11:31.960 --> 0:11:34.360 into the insane this islum if they can't figure this out. 0:11:34.840 --> 0:11:36.880 The basic issue is we have two ways to describe 0:11:36.920 --> 0:11:41.080 the universe. There's general relativity, which tells us about space 0:11:41.240 --> 0:11:44.199 and time and energy and the expansion of the universe. 0:11:44.480 --> 0:11:46.960 Describes a lot of the big stuff. It tells us 0:11:47.080 --> 0:11:50.280 how gravity works and how the universe is expanding and 0:11:50.320 --> 0:11:53.000 how far away galaxies are getting red shifted and all 0:11:53.000 --> 0:11:56.160 that good stuff. And then we have quantum mechanics, which 0:11:56.200 --> 0:11:59.680 describes the really small stuff, the little particles light and 0:11:59.720 --> 0:12:02.120 all the kind of quantum fields and sort of our 0:12:02.200 --> 0:12:06.200 understanding of microscopic matter. And the issue is that we 0:12:06.240 --> 0:12:09.200 don't know how to make these two things play well together. 0:12:09.800 --> 0:12:13.839 They don't play nice because I've actually, I think I've 0:12:13.840 --> 0:12:15.800 been on the show a couple times when we talked 0:12:15.800 --> 0:12:19.480 about this conundrum, and so it seems like, you know, 0:12:19.520 --> 0:12:23.240 when you have these mathematical theories that describe each of them, 0:12:23.280 --> 0:12:27.079 it works within it. So the general relativity math works 0:12:27.120 --> 0:12:30.640 within general relativity. It seems really nice and neat and good. 0:12:30.920 --> 0:12:33.920 Same thing for quantum mechanics. But then when you try 0:12:33.960 --> 0:12:38.360 to cross the beams the math beams, suddenly it doesn't work. 0:12:38.480 --> 0:12:41.080 Like if you're trying to use general relativity math to 0:12:41.360 --> 0:12:46.160 describe what you know is observed in experiments happening on 0:12:46.360 --> 0:12:48.760 sort of the quantum level or vice versa, it no 0:12:48.880 --> 0:12:50.880 longer works. Is that more or less? 0:12:51.559 --> 0:12:53.959 Yeah, I love crossing the math beams. That's awesome. I 0:12:54.000 --> 0:12:56.720 want a T shirt that says I'm crossing the math beams. 0:12:57.200 --> 0:13:00.079 But yeah, that's basically the idea. And remember that what 0:13:00.160 --> 0:13:03.160 we're doing in physics is trying to build a mental 0:13:03.240 --> 0:13:08.200 model that describes the universe easy. Those mental models are 0:13:08.240 --> 0:13:12.720 always imperfect, they're always incomplete, they're always simplifications. Even if 0:13:12.720 --> 0:13:15.280 you're talking about like the flight of a baseball, Right, 0:13:15.360 --> 0:13:17.959 how does a baseball fly across the field? Well, I'm 0:13:17.960 --> 0:13:20.679 going to use a parabola in Newton's equations, but I 0:13:20.720 --> 0:13:23.200 can't do the calculation very easily. I fad to include 0:13:23.240 --> 0:13:25.600 air resistance, so I decide I'm not including that because 0:13:25.600 --> 0:13:28.880 it's probably not important, and really, to answer my question 0:13:29.000 --> 0:13:30.880 of whether the guy's going to catch it, air resistance 0:13:30.920 --> 0:13:33.640 doesn't matter. I'm not going to include effects of humidity 0:13:33.640 --> 0:13:36.199 and the sizillion things I could include in my model 0:13:36.240 --> 0:13:38.959 to make it a very accurate description of the universe 0:13:39.120 --> 0:13:41.800 that I don't need to to answer my question. And 0:13:41.880 --> 0:13:44.440 so the models that we build to answer questions about 0:13:44.440 --> 0:13:48.200 the universe are always incomplete. There are always approximations, but 0:13:48.240 --> 0:13:50.760 they're still very, very useful, And that's The issue with 0:13:50.840 --> 0:13:53.400 quantum mechanics and general relativity is that they are two 0:13:53.520 --> 0:13:57.520 different approximate descriptions of the universe that make different approximations, 0:13:57.559 --> 0:14:01.440 different foundational assumptions that go in building those models that 0:14:01.520 --> 0:14:04.439 are incompatible, and they let us describe different parts of 0:14:04.480 --> 0:14:07.000 the universe, as you say, very very well. So if 0:14:07.000 --> 0:14:09.280 I want to talk about how two electrons scatter off 0:14:09.280 --> 0:14:11.800 of each other, I can use quantum mechanics and talk 0:14:11.840 --> 0:14:14.640 about how they interact and the virtual particles they exchange 0:14:14.720 --> 0:14:16.520 or the fields that ripple between them, and it all 0:14:16.559 --> 0:14:19.680 works out amazingly well. And that can ignore what general 0:14:19.720 --> 0:14:22.840 relativity would do in that situation because it's irrelevant. It's 0:14:22.880 --> 0:14:25.320 like the wind resistance or the humidity on the baseball. 0:14:25.480 --> 0:14:28.040 It doesn't affect the calculations, so I can ignore it. 0:14:28.720 --> 0:14:31.200 Or if I want to say, hey, how do galaxies 0:14:31.240 --> 0:14:33.800 form and how do they swirl around each other? I 0:14:33.840 --> 0:14:37.240 can use general relativity to answer those questions, and I 0:14:37.240 --> 0:14:40.320 can ignore the quantum effects because who cares what one 0:14:40.400 --> 0:14:44.520 electron does in Andromeda doesn't affect whether our galaxy is 0:14:44.560 --> 0:14:48.400 going to crash into that galaxy. General relativity dominates. The 0:14:48.440 --> 0:14:52.000 amazing thing is that in every situation in our universe, 0:14:52.040 --> 0:14:55.200 you can use either quantum mechanics to explain it or 0:14:55.360 --> 0:14:58.400 general relativity and ignore the other one. They're like a 0:14:58.400 --> 0:15:00.920 perfect divorced couple that have separate to their lives and 0:15:01.040 --> 0:15:03.720 never have to interact. You know, there are no arguments 0:15:03.720 --> 0:15:08.280 at McDonald's about who's taking the case. They're co parenting 0:15:08.320 --> 0:15:11.080 the universe. And so you might think, all right, great, 0:15:11.240 --> 0:15:14.400 what's the problem, right co parents can live in harmony 0:15:14.440 --> 0:15:17.320 without ever talking to each other. Well, there's two problems. 0:15:17.440 --> 0:15:21.440 One is that's really unsatisfying, right, Like, we want one 0:15:21.560 --> 0:15:25.200 explanation for the universe. We don't want two different explanations. 0:15:25.360 --> 0:15:28.440 We don't want a Russiaman universe where both parents tell 0:15:28.600 --> 0:15:31.240 very very different stories about what's going on. Right. 0:15:31.520 --> 0:15:35.600 Note, we think that. 0:15:35.600 --> 0:15:39.000 There is one story about the universe. There's something that's happening, 0:15:39.080 --> 0:15:41.080 and that there are rules that are being followed, and 0:15:41.120 --> 0:15:43.040 we want to know what they are. We want our 0:15:43.120 --> 0:15:47.200 best approximation of them. So it's deeply unsatisfying to have 0:15:47.240 --> 0:15:51.680 two different, incompatible theories of the universe. And also, there 0:15:51.680 --> 0:15:54.760 are moments in the universe, a very few places in 0:15:54.800 --> 0:15:57.560 times when you can't ignore one war or the other. 0:15:57.640 --> 0:16:00.640 You need both things like the heart of a black 0:16:00.680 --> 0:16:05.520 hole a singularity. In general, relativity is incompatible with quantum mechanics, 0:16:05.560 --> 0:16:08.400 which says you've got to have some fuzziness or the 0:16:08.440 --> 0:16:11.440 Big Bang or the very early universe when things were really, 0:16:11.480 --> 0:16:13.800 really hot and dense. You need the rules of quantum 0:16:13.800 --> 0:16:16.880 mechanics to describe those particles. But you can't ignore gravity 0:16:16.920 --> 0:16:19.520 because things are so hot and so dense. So we 0:16:19.640 --> 0:16:22.040 desperately want to find a way to bring these two together. 0:16:22.360 --> 0:16:25.920 But as you say, the math beams don't cross, right. 0:16:26.000 --> 0:16:29.280 I mean, it's like, as physicists you now kind of 0:16:29.280 --> 0:16:32.520 have to play as a couple's therapists, where you have 0:16:32.600 --> 0:16:36.920 these two theories that are essentially speaking different languages, and 0:16:36.960 --> 0:16:41.200 they cannot come to an agreement, and they can be 0:16:41.280 --> 0:16:44.080 perfectly functional on their own, but then when they come together, 0:16:44.200 --> 0:16:48.840 they are unable to communicate. And the Yeah, I mean, 0:16:48.840 --> 0:16:53.720 it seems like resolving that difference between the two theories, 0:16:53.720 --> 0:16:56.760 like resolving why they don't work with each other, would 0:16:56.800 --> 0:17:02.200 actually reveal some big things that we just fundamentally have 0:17:02.320 --> 0:17:04.160 not understood yet about the universe. 0:17:04.359 --> 0:17:06.840 M M. You know, I've heard anecdotally about couples that 0:17:06.880 --> 0:17:09.159 don't actually speak the same language you know where they 0:17:09.160 --> 0:17:12.760 have like literally have now yet they've fallen in love. 0:17:14.359 --> 0:17:17.200 That's actually true, they have some other love language. 0:17:16.960 --> 0:17:19.960 Hi language interpret of there love. 0:17:19.800 --> 0:17:22.200 At first sight, right, doesn't love it first word. 0:17:22.359 --> 0:17:22.800 Yeah. 0:17:22.880 --> 0:17:25.560 Anyway, you're right that quantum mechanics in general relativity don't 0:17:25.560 --> 0:17:28.160 get along, and one of the reasons is that they 0:17:28.160 --> 0:17:31.160 are built on very different assumptions. Like general relativity says 0:17:31.200 --> 0:17:35.560 the universe is smooth, it's continuous, it's precise, there's an 0:17:35.640 --> 0:17:38.960 infinite number of locations. It says that you can divide 0:17:39.040 --> 0:17:42.240 space an infinite number of times, like relativity agrees with 0:17:42.320 --> 0:17:45.560 Zeno's paradox, right that between you and the candy store, 0:17:45.640 --> 0:17:47.960 there's always a distance that you can cut in half. 0:17:48.480 --> 0:17:50.560 Space from the point of view of general relativity is 0:17:50.600 --> 0:17:53.679 something that's smooth and continuous and you always have a 0:17:53.760 --> 0:17:57.800 very specific location, whereas quantum mechanics says not nothing is 0:17:57.880 --> 0:18:01.080 actually smooth and continuous. There aren't not infinite number of 0:18:01.119 --> 0:18:04.560 locations between any two points. Things are discrete and chunky. 0:18:04.880 --> 0:18:07.040 A beam of light is actually made up of little 0:18:07.080 --> 0:18:10.080 pieces of light, little packets of light. Everything in the 0:18:10.160 --> 0:18:14.520 universe is discrete, and it's also imprecise. None of these 0:18:14.560 --> 0:18:18.280 little packets have a precise location that have probabilities. So 0:18:18.280 --> 0:18:21.160 you see the foundations of these two theories are very 0:18:21.240 --> 0:18:23.919 very different. They start from two very different places, and 0:18:24.000 --> 0:18:27.000 so weave in them together has a lot of challenges. 0:18:27.400 --> 0:18:30.280 People have been trying to make theories of quantum gravity 0:18:30.520 --> 0:18:33.200 to say, hey, let's take gravity and try to describe 0:18:33.200 --> 0:18:36.160 it in the language of quantum mechanics. For example, think 0:18:36.200 --> 0:18:39.840 of it like a quantum field. They are exchanging virtual particles. 0:18:40.200 --> 0:18:41.880 They even have a name for these particles. It would 0:18:41.880 --> 0:18:44.280 be the graviton. But when you sit down and try 0:18:44.280 --> 0:18:46.960 to do those calculations, gravity is different from the other 0:18:47.080 --> 0:18:50.880 quantum forces because it couples to itself. Everything that has 0:18:51.000 --> 0:18:53.240 energy has gravity, and so if you emit a graviton, 0:18:53.440 --> 0:18:56.680 it also feels gravity, and it emits gravitons, which emit 0:18:56.760 --> 0:19:00.359 more gravitons. You can infinite number of graviton and then 0:19:00.359 --> 0:19:03.160 you start to get nonsense answers. So as you say, 0:19:03.160 --> 0:19:04.640 the math beams don't cross. 0:19:05.119 --> 0:19:08.679 So in terms of gravitons, is that something that has 0:19:08.800 --> 0:19:11.720 ever been able to be studying in the same way 0:19:11.760 --> 0:19:14.200 that you can study protons or is it just sort 0:19:14.200 --> 0:19:17.480 of a byproduct of this? Seems like this could be 0:19:17.520 --> 0:19:21.639 a thing based on the math that we have theorized about. 0:19:21.840 --> 0:19:26.120 Yeah, gravitons are purely theoretical, and they're not even coherently theoretical. 0:19:26.560 --> 0:19:29.400 Theories that have gravitons in them just don't work their 0:19:29.520 --> 0:19:32.159 problems with them, and so it's not just that we 0:19:32.200 --> 0:19:34.439 haven't seen them. We don't even understand how they would 0:19:34.440 --> 0:19:37.359 work if they did exist. And there also would be 0:19:37.359 --> 0:19:40.320 really really hard to spot, Like if you're thinking about 0:19:40.359 --> 0:19:45.160 gravitational waves from rotating black holes, for example, those are 0:19:45.200 --> 0:19:48.399 not gravitons. Those are ripples in space and time. They 0:19:48.400 --> 0:19:51.199 are like a beam of light. Gravitons would be like 0:19:51.240 --> 0:19:53.879 taking that beam of light and breaking it up into photons. 0:19:53.920 --> 0:19:56.040 So you take that gravitational wave and now break it 0:19:56.119 --> 0:20:00.320 up into tiny little gravitons. But even gravitational waves are 0:20:00.320 --> 0:20:03.520 really hard to see. Gravitons would be much much tinier, 0:20:03.960 --> 0:20:08.200 well beyond our capability. But also mathematically they just don't work. 0:20:08.240 --> 0:20:10.840 If you try to do calculations with gravitons, you get 0:20:10.880 --> 0:20:14.359 weird answers, like what's the probability that this electron is 0:20:14.400 --> 0:20:16.760 going to go left. Oh, one hundred and forty percent. 0:20:17.119 --> 0:20:19.440 What that doesn't make any sense, right, And so that's 0:20:19.480 --> 0:20:21.639 telling you that fundamentally there is a problem with the 0:20:21.640 --> 0:20:24.520 mathematics that you need to go deeper and start from 0:20:24.560 --> 0:20:27.560 something else, change one of your assumptions in order to 0:20:27.560 --> 0:20:29.520 make a working theory of quantum gravity. 0:20:29.880 --> 0:20:32.479 I mean this kind of reminds me in biology of 0:20:32.480 --> 0:20:35.520 how like the history of biology and medicine, where we 0:20:35.560 --> 0:20:38.320 would start to understand things like we would start to 0:20:38.560 --> 0:20:43.960 understand how certain medications work, or you know, understand things like, 0:20:44.040 --> 0:20:46.000 you know, a man and a woman make a baby 0:20:46.160 --> 0:20:50.760 and the like. There seems to be these germinal cells responsible. 0:20:50.760 --> 0:20:55.360 But then we didn't have the ability to get tiny 0:20:55.480 --> 0:20:59.160 enough inside the human body where we couldn't see like proteins, 0:20:59.160 --> 0:21:02.080 we couldn't see you know, maybe we at some point 0:21:02.080 --> 0:21:05.600 could see cells, but we couldn't see DNA. So there 0:21:05.640 --> 0:21:10.000 were so many strange and interesting theories that kept circling 0:21:10.040 --> 0:21:12.480 around trying to get closer and closer to the truth. 0:21:12.880 --> 0:21:15.600 Like there were really funny ones like imagining that there's 0:21:15.680 --> 0:21:18.760 just like a tiny person inside of a sperm cell 0:21:18.800 --> 0:21:22.280 and then that grew into a baby. But essentially it's 0:21:22.359 --> 0:21:26.520 like we were able to make scientific observations, but without 0:21:26.560 --> 0:21:29.439 the ability to get small enough in terms of like 0:21:29.480 --> 0:21:32.840 we didn't have electron microscopes, we didn't have the technology 0:21:32.920 --> 0:21:36.800 or understanding to study DNA. These theories could not kind 0:21:36.840 --> 0:21:40.160 of you know, interweave until we got to that point. 0:21:40.600 --> 0:21:43.960