WEBVTT - Ep128 "Would space aliens see the world as we do?" with Daniel Whiteson 0:00:05.120 --> 0:00:08.879 What's going to happen if we eventually meet space aliens, 0:00:08.960 --> 0:00:15.560 and specifically alien scientists. If these aliens could see electrons 0:00:15.720 --> 0:00:20.800 or smell photons, would their science look anything like ours? 0:00:21.400 --> 0:00:26.000 Is physics a universal language or just a local dialect 0:00:26.040 --> 0:00:30.400 of the human brain? Would alien scientists even use math 0:00:30.440 --> 0:00:34.360 and equations? Or might their truths be organized in a 0:00:34.400 --> 0:00:37.800 way that we just don't recognize. Are the laws of 0:00:37.920 --> 0:00:42.680 nature really laws or simply the stories that our species 0:00:42.800 --> 0:00:47.320 tells about its slice of reality? Could alien technology emerge 0:00:47.360 --> 0:00:51.599 from entirely different questions, things that we find boring or 0:00:51.640 --> 0:00:55.840 irrelevant or literally invisible. What would it mean if science 0:00:55.880 --> 0:00:59.600 itself is not universal but just another product of evolution. 0:01:00.200 --> 0:01:04.039 Today we'll speak with physicist Daniel Whitson, who's just written 0:01:04.080 --> 0:01:08.360 a new book called Do Aliens Speak Physics? So get 0:01:08.400 --> 0:01:15.720 ready for a terrific brain stretch. Welcome to Intercosmos with 0:01:15.760 --> 0:01:19.480 me David Eagleman. I'm a neuroscientist and author at Stanford 0:01:19.520 --> 0:01:22.720 and in these episodes we sail deeply into our three 0:01:22.880 --> 0:01:24.199 pound universe. 0:01:24.000 --> 0:01:27.039 To understand how we see the world. 0:01:26.720 --> 0:01:31.360 And sometimes how different creatures might see the world very differently. 0:01:44.160 --> 0:01:48.240 So let's start here when we imagine extraterrestrial life, we 0:01:48.360 --> 0:01:52.760 usually picture aliens through the only template that we know, 0:01:52.880 --> 0:01:56.960 which is a mashup of Earth creatures, including aliens we've 0:01:56.960 --> 0:02:01.160 seen in movies and television. We see animals stretched and 0:02:01.240 --> 0:02:05.840 tinted into something just foreign enough to qualify as aliens. 0:02:05.920 --> 0:02:08.800 They might have big eyes and green skin, and maybe 0:02:09.080 --> 0:02:14.160 tentacles or extra limbs. But quite possibly, when we do 0:02:14.240 --> 0:02:17.320 find alien life, we're going to find that it looks 0:02:17.840 --> 0:02:21.560 much much different than what we have pictured so far. Now, 0:02:21.560 --> 0:02:23.840 I just want to bring that up as a table 0:02:23.960 --> 0:02:28.520 setting for today's much deeper question. Not about what aliens 0:02:28.600 --> 0:02:32.080 might look like, it's about how they might think. 0:02:32.800 --> 0:02:33.880 Here's why this matters. 0:02:34.480 --> 0:02:38.720 Every creature on our planet already lives within its own 0:02:39.000 --> 0:02:44.919 private universe, a unique umvelt or sensory world. My dog, 0:02:45.040 --> 0:02:49.639 for example, navigates our neighborhood through a riot of smells. 0:02:50.240 --> 0:02:52.640 So to me, the fire hydrant is just a short 0:02:52.680 --> 0:02:56.680 metal post, but to him, it's a tapestry of stories 0:02:56.720 --> 0:03:01.359 that are woven from the animals that passed. And when 0:03:01.400 --> 0:03:03.360 I'm away from home and I pop in on a 0:03:03.440 --> 0:03:07.000 video call, my family is happy to see me, but 0:03:07.080 --> 0:03:11.200 my dog quickly loses interest. Here's my voice, but it 0:03:11.240 --> 0:03:14.440 doesn't smell like I'm there, and so to his brain, 0:03:14.680 --> 0:03:20.280 I'm not really there, and our human umvelt is shockingly limited. 0:03:20.320 --> 0:03:22.320 If you're interested in this, check out a talk I 0:03:22.360 --> 0:03:25.600 gave it ted some years ago. We humans are tuned 0:03:25.600 --> 0:03:31.000 into a tiny sliver of the electromagnetic spectrum, like one 0:03:31.200 --> 0:03:35.360 ten trillionth of it, So we are blind to most 0:03:35.400 --> 0:03:38.000 of the light that makes up the world, and for 0:03:38.080 --> 0:03:42.080 that matter, we are deaf to most sound frequencies out there, 0:03:42.400 --> 0:03:46.600 and we have absolutely zero perception of lots of things 0:03:46.640 --> 0:03:51.480 around us, like neutrinos or dark matter. We stitch together 0:03:51.760 --> 0:03:57.200 our reality from a surprisingly thin trickle of signals, and 0:03:57.240 --> 0:04:00.640 then we build our sciences on top of that's gaffolding, 0:04:01.200 --> 0:04:05.040 which raises the question if our physics is built on 0:04:05.080 --> 0:04:08.840 our senses in some way, then what would science look 0:04:08.960 --> 0:04:12.560 like to a creature with utterly different senses. 0:04:13.120 --> 0:04:17.960 Imagine aliens who can see electrons, or smell photons, or 0:04:18.000 --> 0:04:21.719 feel dark matter the way that we see and smell 0:04:21.760 --> 0:04:24.880 and taste in apple. Would they arrive at the same 0:04:25.080 --> 0:04:29.760 equations we do? Would they describe the universe with particles 0:04:29.800 --> 0:04:33.839 and forces, or would those concepts feel to them something 0:04:33.960 --> 0:04:37.360 like Roman numerals, which we'll talk about in a bit now. 0:04:37.400 --> 0:04:40.600 The reason this is worth asking is because many physicists 0:04:40.720 --> 0:04:45.800 assume that uncovering the rules of nature is a universal project, 0:04:45.880 --> 0:04:50.440 one that any intelligent species anywhere in the galaxy would 0:04:50.520 --> 0:04:54.480 naturally embark on. But what if that's not true, and 0:04:54.520 --> 0:04:58.680 that the physics we uncover is going to be very specific, 0:04:58.760 --> 0:05:01.720 not only to our culture, but also to our cognition 0:05:01.800 --> 0:05:05.560 and our biology. What if physics is less like a 0:05:05.839 --> 0:05:09.400 mirror of the universe and more like a lens, like 0:05:09.480 --> 0:05:13.560 a little narrow straw we're looking through. These questions cut 0:05:13.600 --> 0:05:15.520 to the heart of what science is. 0:05:15.520 --> 0:05:17.880 Is it a singular, convergent. 0:05:17.360 --> 0:05:21.320 Path towards truth or is it a story where different observers, 0:05:21.760 --> 0:05:25.560 bound by their unique sensory limits, tell very different tales 0:05:25.600 --> 0:05:29.160 about reality. That's the territory we get to explore today 0:05:29.520 --> 0:05:33.680 with my guest physicist and author Daniel Whitson. These are 0:05:33.720 --> 0:05:36.960 exactly the questions that he has been asking. If and 0:05:37.040 --> 0:05:41.560 when we meet aliens, will their breakthroughs unlock mysteries that 0:05:41.600 --> 0:05:45.640 we still fumble with, or will their science maybe be 0:05:45.839 --> 0:05:50.920 something we wouldn't even recognize as science. Daniel Whitson is 0:05:50.960 --> 0:05:53.800 a particle physicist that you see Irvine and he's the 0:05:53.839 --> 0:05:58.480 co host of the podcast Daniel N. Kelly's Extraordinary Universe. 0:05:58.680 --> 0:06:01.159 He's also the co author of SI several books exploring 0:06:01.200 --> 0:06:05.239 the big questions at the edge of physics. His latest book, 0:06:05.240 --> 0:06:09.160 which comes out this week, is called Do Aliens Speak Physics? 0:06:09.520 --> 0:06:12.560 And it dives straight into this puzzle what aliens might 0:06:12.640 --> 0:06:15.760 know that we don't know, and how their science might 0:06:15.880 --> 0:06:18.760 diverge from ours in ways we haven't considered. 0:06:19.080 --> 0:06:19.880 So let's dive in. 0:06:24.520 --> 0:06:29.080 Okay, So, Daniel, when sociologists look across cultures, they find 0:06:29.160 --> 0:06:33.440 various things where they say, look, this is culturally arbitrary. 0:06:33.480 --> 0:06:36.320 This just happens to come from the history of this 0:06:36.360 --> 0:06:39.480 particular culture. Now, the question you're asking is when we 0:06:39.560 --> 0:06:43.520 discover alien life, will we realize that something about our 0:06:43.680 --> 0:06:48.320 math in physics islet's say, culturally arbitrary or is there 0:06:48.400 --> 0:06:50.080 something fundamental about that? 0:06:50.160 --> 0:06:51.640 So let's dive into that. 0:06:51.760 --> 0:06:52.000 Yeah. 0:06:52.040 --> 0:06:54.320 I think it's a really important question we haven't spent 0:06:54.480 --> 0:06:58.280 enough time thinking about. But like lots of questions about aliens, 0:06:58.600 --> 0:07:02.560 either answer is amazing, like, either the aliens are doing 0:07:02.560 --> 0:07:05.240 physics the way that we are, which means that we're 0:07:05.279 --> 0:07:07.960 luck uncovering the truth. We're like revealing the nature of 0:07:08.000 --> 0:07:12.880 the universe itself, which makes our physics incredibly powerful and relevant. 0:07:12.440 --> 0:07:13.560 Across the galaxy. 0:07:14.320 --> 0:07:17.080 Or aliens are doing physics in a very different way 0:07:17.080 --> 0:07:19.680 than we are. Maybe they're perceiving a different slice of 0:07:19.720 --> 0:07:21.880 the universe, or they're asking different questions, or they have 0:07:22.000 --> 0:07:25.239 found different answers, or they just take a different approach 0:07:25.280 --> 0:07:29.440 because of their path through exploring the universe. In that case, 0:07:29.600 --> 0:07:32.720 we have an opportunity to learn something really fascinating about 0:07:32.760 --> 0:07:37.200 the lens of the human experience, how our humanity has 0:07:37.320 --> 0:07:40.920 colored the physics the explanations that we've developed about our experience. So, 0:07:41.320 --> 0:07:44.080 either way, when we discover aliens, you can get to 0:07:44.160 --> 0:07:45.440 try to talk physics with them. 0:07:45.480 --> 0:07:47.080 We're going to learn something fantastic. 0:07:47.280 --> 0:07:49.200 And so the way that you go about this in 0:07:49.240 --> 0:07:52.640 your fantastic new book is you say, look, this is 0:07:52.720 --> 0:07:55.240 the Drake equation, and I'm going to propose sort of 0:07:55.240 --> 0:07:57.800 an extension of it. So let's remind our listeners what 0:07:57.840 --> 0:07:59.880 the Drake equation is first, and then tell us by 0:07:59.840 --> 0:08:00.400 your extension. 0:08:01.000 --> 0:08:03.400 Yeah, so the Drake equation is a way to try 0:08:03.400 --> 0:08:06.160 to estimate how many aliens are out there that we 0:08:06.240 --> 0:08:10.160 could communicate with, and this seems like a really overwhelming question. 0:08:10.400 --> 0:08:12.400 And so the beauty of the Drake equation, though it's 0:08:12.440 --> 0:08:14.720 so simple it's just a bunch of numbers multiplied together, 0:08:15.480 --> 0:08:17.760 is that it expresses it in parts. It says, well, 0:08:17.800 --> 0:08:21.080 let's just start by asking how many stars are there 0:08:21.200 --> 0:08:23.640 out there in the galaxy, and that turns out to 0:08:23.640 --> 0:08:26.600 be a huge number. We now know hundreds of billions, 0:08:26.800 --> 0:08:29.200 which is a great start. But then it asks, well, 0:08:29.240 --> 0:08:33.079 what fraction of those stars have planets where life might evolve, 0:08:33.120 --> 0:08:35.320 And then what fraction of those planets might have life, 0:08:35.320 --> 0:08:38.320 and what fraction of that life might be intelligent, what 0:08:38.360 --> 0:08:43.160 fraction of those intelligent civilizations might develop technology that could 0:08:43.160 --> 0:08:46.800 communicate with us, and what fraction of those exist in 0:08:46.880 --> 0:08:50.320 the right time period to talk to us. So the 0:08:50.400 --> 0:08:53.720 structure of the Drake equation, multiplying all these terms together 0:08:53.960 --> 0:08:57.439 emphasizes something really important, which is for this to work, 0:08:57.559 --> 0:08:59.960 for there to be aliens out there in the universe 0:09:00.080 --> 0:09:02.360 that are similar enough for us to talk to them, 0:09:02.800 --> 0:09:05.280 everything has to fall into place. You need a star, 0:09:05.400 --> 0:09:07.400 you need a planet, you need life, you need intelligence, 0:09:07.400 --> 0:09:10.560 you need civilization, you need technology, and you need the time. 0:09:10.840 --> 0:09:13.560 If any of those numbers are zero, then you got 0:09:13.559 --> 0:09:16.640 to know aliens. Like people often say, look, of course 0:09:16.640 --> 0:09:19.479 they're aliens out there. Look at the number of planets. 0:09:19.559 --> 0:09:22.120 There's a huge number of planets out there. Yeah, but 0:09:22.840 --> 0:09:24.840 if the fraction of those that have life is one 0:09:24.960 --> 0:09:28.560 over ten to the fifty, then we're alone in the 0:09:28.600 --> 0:09:33.920 galaxy despite the huge number of stars and planets. So 0:09:34.000 --> 0:09:36.360 that's the concept behind the Drake equation, but the structure 0:09:36.400 --> 0:09:39.280 of it really emphasizes how you need all these pieces 0:09:39.320 --> 0:09:42.640 to come together in order to have that contact with aliens. 0:09:43.160 --> 0:09:46.160 Now, what you've proposed is an extension to that. Tell 0:09:46.200 --> 0:09:46.640 us about that. 0:09:46.760 --> 0:09:50.120 Yeah, So I'm not just satisfied with there being aliens 0:09:50.160 --> 0:09:52.840 out there. I want to talk to aliens about physics. 0:09:52.880 --> 0:09:56.000 I want to know are they on the same path 0:09:56.040 --> 0:09:58.600 as we are, but maybe like a thousand, a million, 0:09:58.640 --> 0:10:01.920 a billion years ahead, Like we have been banging our 0:10:01.960 --> 0:10:04.800 heads on, you know, the question of quantum gravity for 0:10:04.800 --> 0:10:08.440 one hundred years. How do we reconcile Einstein's theory of 0:10:08.440 --> 0:10:12.360 relativity with our knowledge that the universe is fundamentally uncertain. 0:10:12.559 --> 0:10:14.679 These two things just don't fit together, and we've been 0:10:14.720 --> 0:10:17.920 trying and struggling, and there's many deep questions in physics 0:10:17.920 --> 0:10:20.880 that we could answer. But what are the aliens just 0:10:21.040 --> 0:10:22.920 know the answers? You know, what have they have this 0:10:23.000 --> 0:10:25.840 figured out? They've have answers to questions we haven't even 0:10:25.840 --> 0:10:29.640 imagined yet. That would be so fantastic. So in this book, 0:10:29.679 --> 0:10:34.839 I imagine or try to estimate what fraction of the aliens 0:10:34.880 --> 0:10:38.400 out there could talk to us about physics. And in 0:10:38.520 --> 0:10:40.560 order for that to happen, a lot of things have 0:10:40.600 --> 0:10:43.000 to fall into place, and that's sort of the structure. 0:10:42.559 --> 0:10:44.080 Of the book. Number one. 0:10:44.520 --> 0:10:46.800 They have to be interested in these questions, have to 0:10:46.840 --> 0:10:49.800 be doing science in the first place, Like how do 0:10:49.880 --> 0:10:54.240 we know that aliens wonder why? And like lots of 0:10:54.240 --> 0:10:56.360 the questions in the book, your initial reaction is, well, 0:10:56.400 --> 0:10:58.800 of course they do, or you know they have to. 0:10:59.320 --> 0:11:01.560 But that's exactly the intuition I want to dig into 0:11:01.640 --> 0:11:05.200 because often we're biased as humans. We tend to think 0:11:05.240 --> 0:11:07.360 that our example, the way we do things, the place 0:11:07.440 --> 0:11:10.800 we live, our location in the universe is important or 0:11:10.840 --> 0:11:15.280 central or fundamental, and the history of science has taught us, 0:11:15.600 --> 0:11:18.760 or a history of philosophy has taught us that unpacking 0:11:18.800 --> 0:11:21.320 those skepticism is very valuable. 0:11:21.559 --> 0:11:26.199 So for example, you know, kangaroos don't particularly care about 0:11:26.200 --> 0:11:27.960 any questions that we have here. 0:11:28.440 --> 0:11:29.240 Or you can. 0:11:29.080 --> 0:11:34.000 Imagine space aliens that care about a very different set 0:11:34.040 --> 0:11:35.559 of questions than we do. 0:11:36.559 --> 0:11:38.240 We'll be an example of that. 0:11:39.280 --> 0:11:41.920 Yeah, So the kind of things that we're excited about 0:11:42.040 --> 0:11:46.240 are like, hey, how do planets form? You know, what 0:11:46.400 --> 0:11:48.720 are the conditions under which planets form? And how long 0:11:48.760 --> 0:11:49.439 do they survive? 0:11:49.480 --> 0:11:49.680 Etc. 0:11:50.200 --> 0:11:52.600 Why Because we have all done a planet and so 0:11:52.679 --> 0:11:56.000 we tend to think planets are really important, but planets 0:11:56.040 --> 0:11:58.319 are sort of an arbitrary, made up thing. And the 0:11:58.360 --> 0:12:00.959 whole like argument in the last ten years about what 0:12:01.040 --> 0:12:02.480 is a planet is plue to a planet? 0:12:02.520 --> 0:12:04.960 How do you define a planet? Really reveals that. 0:12:05.440 --> 0:12:09.720 I mean, planets are tiny little dots around stars. Think 0:12:09.720 --> 0:12:13.920 about the way that we depict the Solar System. You know, 0:12:14.080 --> 0:12:15.920 typically we have the Sun, we have all the planets, 0:12:15.920 --> 0:12:18.400 and they're roughly the same size, which means that we've 0:12:18.440 --> 0:12:21.480 like taken the planets and blown them up right way 0:12:21.640 --> 0:12:24.560 beyond their real size because they're important to us. 0:12:24.720 --> 0:12:27.360 Whereas the Sun is actually one million times larger than 0:12:27.360 --> 0:12:28.040 the areth. 0:12:27.840 --> 0:12:31.280 Yeah, the Solar System is basically the Sun plus a 0:12:31.280 --> 0:12:32.600 couple little details, right, the. 0:12:32.559 --> 0:12:34.200 Sun, Jupiter, dot dot dot. 0:12:34.920 --> 0:12:36.920 But in our depictions we blow up the planets, and 0:12:37.320 --> 0:12:40.199 you know, the definition of a planet isn't even something 0:12:40.240 --> 0:12:42.880 that people agree on. Art astroomers are still arguing about it. 0:12:42.880 --> 0:12:45.400 And the reason is that it's important to us. It's 0:12:45.440 --> 0:12:48.720 not fundamentally important to the universe. The Solar System turns 0:12:48.720 --> 0:12:51.080 out to be, you know, mostly the Sun plus a 0:12:51.120 --> 0:12:54.080 bunch of rocks of different sizes and shapes. And we 0:12:54.320 --> 0:12:57.440 have drawn arbitrary dotted lines around this concept of a 0:12:57.440 --> 0:12:59.959 planet because we grew up on one, so we think 0:13:00.080 --> 0:13:03.719 it's important. What if aliens evolved in the atmospheres of 0:13:03.760 --> 0:13:06.760 stars and they're like planets, who cares, or you know, 0:13:06.960 --> 0:13:11.520 around in an ocean on a moon and they're like, yeah, planets, 0:13:11.640 --> 0:13:13.960 you know, are not the most important thing. I think 0:13:14.000 --> 0:13:17.680 the experience of our humanity that leads us to things 0:13:17.679 --> 0:13:21.040 that certain things are fundamental and important, and aliens might 0:13:21.040 --> 0:13:23.280 come out of from a different way and ask different questions, 0:13:23.600 --> 0:13:26.400 and so that's another element of this extended ray equation. First, 0:13:26.440 --> 0:13:29.440 I ask do aliens do science at all? Because if not, 0:13:30.160 --> 0:13:32.520 what can we talk to them about if they don't 0:13:32.520 --> 0:13:35.959 even care? And then I ask, could we actually make 0:13:36.000 --> 0:13:39.880 a mental contact with them? Could we establish communication? Could 0:13:39.920 --> 0:13:43.439 we learn to translate these concepts in our minds into 0:13:43.520 --> 0:13:46.680 alien brains? And back and forth? And then as you say, 0:13:46.800 --> 0:13:49.000 do they ask the same questions? Are they interested in 0:13:49.040 --> 0:13:51.079 the same things? Do they perceive the same parts of 0:13:51.120 --> 0:13:54.280 the universe even? And then finally the answer is the 0:13:54.360 --> 0:13:58.119 juicy thing I ask in the book, could we understand 0:13:58.160 --> 0:14:01.520 alien answers? Or is it possible aliens have an alternative 0:14:01.520 --> 0:14:04.400 theory of physics that works just as well as ours 0:14:04.679 --> 0:14:07.400 but tells a very, very different story about what's happening 0:14:07.440 --> 0:14:10.520 in the universe. So, because this question of like do 0:14:10.640 --> 0:14:13.440 aliens do physics like we do? Is too big and overwhelming, 0:14:13.800 --> 0:14:16.360 I extended the Drake equation use the same structure to 0:14:16.440 --> 0:14:19.520 ask in turn, like do they do science? Can we 0:14:19.520 --> 0:14:22.000 communicate with them? Do they have the same questions? And 0:14:22.080 --> 0:14:24.520 do they have the same answers? Those are other terms 0:14:24.520 --> 0:14:26.200 and the extended Drake equation. 0:14:26.640 --> 0:14:30.520 So let's start with this issue about would aliens use 0:14:31.080 --> 0:14:33.920 math and physics the kind of tools that we use, 0:14:34.240 --> 0:14:35.520 or might they use something else? 0:14:35.680 --> 0:14:36.040 Entirely. 0:14:36.600 --> 0:14:40.080 Yeah, this is something that's often cited as a great 0:14:40.080 --> 0:14:43.359 way to start talking to aliens is to begin with mathematics, 0:14:43.360 --> 0:14:46.760 because mathematics is so basic to our science, and some 0:14:46.800 --> 0:14:50.000 people think it must be fundamental to the universe. And 0:14:50.080 --> 0:14:53.160 there's lots of good arguments that math is part of 0:14:53.160 --> 0:14:57.680 the universe. We as human physicists, have found many times 0:14:57.680 --> 0:15:01.120 that math leads us to the truth, the pure mathematics 0:15:01.120 --> 0:15:04.160 of it. You know, there's an example of group theory. 0:15:04.200 --> 0:15:08.240 This is a concept and abstract algebra that math nerds 0:15:08.240 --> 0:15:10.760 have played around with, you know, hundreds of years ago, 0:15:11.200 --> 0:15:12.800 just because they thought it was cool. They're like, look 0:15:12.800 --> 0:15:14.800 at these patterns. You can play these games. This is 0:15:14.800 --> 0:15:17.720 super awesome. They didn't care who it was relevant. One 0:15:17.760 --> 0:15:21.920 hundred years after they figured it out, the physicists were like, ooh, actually, 0:15:22.000 --> 0:15:25.440 it turns out this perfectly describes the interactions to fundamental 0:15:25.440 --> 0:15:28.640 particles and shows us patterns we hadn't imagined and it 0:15:28.720 --> 0:15:31.560 just clicked into place beautifully. So the math was there 0:15:31.600 --> 0:15:36.240 before the physics, right, and it suggests that the math 0:15:36.400 --> 0:15:40.360 reflects the nature of reality itself. Right, that's not our 0:15:40.440 --> 0:15:45.120 description of reality, but it's somehow revealing the source code itself, 0:15:45.160 --> 0:15:47.760 and of course that's what we want it to be true. 0:15:47.840 --> 0:15:51.200 We want as physicists, we're hoping to unravel the nature 0:15:51.240 --> 0:15:53.920 of reality, not just tell a story about it. We 0:15:53.960 --> 0:15:57.680 want to be describing the territory, not just a random 0:15:57.720 --> 0:16:01.840 map of the territory. So great arguments that math could 0:16:01.880 --> 0:16:03.440 be fundamental, that a math might. 0:16:03.280 --> 0:16:04.600 Be part of the universe. 0:16:05.080 --> 0:16:08.320 But because it's philosophy, of course, there are great arguments 0:16:08.320 --> 0:16:11.240 on the other side also, and there are strong hints 0:16:11.240 --> 0:16:14.920 that suggests that maybe math is a human way of thinking, 0:16:14.920 --> 0:16:18.240 in a way to express human ideas compactly, that maybe 0:16:18.240 --> 0:16:21.200 it's very very useful for doing physics, but maybe it's 0:16:21.240 --> 0:16:25.840 not absolutely necessary in aliens could have a different approach. 0:16:25.600 --> 0:16:28.480 And in fact, if they see the world very differently, 0:16:28.560 --> 0:16:32.320 not picking up on our little tiny window of electromagnetic radiation, 0:16:32.840 --> 0:16:35.320 maybe not picking up on air compression waves the way 0:16:35.360 --> 0:16:38.480 that we do, but living in a really different sort 0:16:38.480 --> 0:16:42.400 of umvelt this notion of what signals you pick up 0:16:42.440 --> 0:16:46.400 from the environment. The question is would they have an 0:16:46.520 --> 0:16:50.840 extraordinarily different way of picking up on information and expressing 0:16:50.880 --> 0:16:53.520 it other than math and physics. 0:16:53.600 --> 0:16:56.120 Exactly, And this is something you must know a lot 0:16:56.160 --> 0:16:59.960 about as a neuroscientist, But our experience of the world 0:17:00.080 --> 0:17:04.240 doesn't perfectly mirror the actual reality out there. Right, we 0:17:04.359 --> 0:17:07.440 have these narrow little conduits from which we get information 0:17:07.520 --> 0:17:11.320 about the world site, sense, touch, et cetera, and they 0:17:11.359 --> 0:17:14.600 create in our minds this sense of what the world is. 0:17:14.680 --> 0:17:18.840 But we also know obviously that is incomplete. Right, Like 0:17:19.200 --> 0:17:21.720 we see certain wavelengths of light, but this light everywhere 0:17:21.720 --> 0:17:24.719 that's invisible to us. We know that there are particles 0:17:25.040 --> 0:17:28.080 flowing through us all the time. Neutrinos are everywhere, and 0:17:28.119 --> 0:17:30.800 they're not and they're not rare. There's like billions of 0:17:30.840 --> 0:17:34.320 neutrinos passing through your fingernails every second. If you could 0:17:34.320 --> 0:17:37.680 see neutrinos, it'd be all you could see. Right, There's 0:17:37.800 --> 0:17:40.119 dark matter out there. There's all sorts of crazy stuff 0:17:40.160 --> 0:17:43.920 that we cannot sensor interact with. So our slice of 0:17:43.960 --> 0:17:48.200 the universe that we perceive is desperately incomplete, which means 0:17:48.640 --> 0:17:52.800 that our sensorium, the idea we have about where we 0:17:52.840 --> 0:17:57.080 are in the universe is something sort of concocted to 0:17:57.440 --> 0:18:00.240 allow us to survive. And you know, evolutionary biology, you said, 0:18:00.240 --> 0:18:02.840 neuroscientist knew much more about that than I do. But 0:18:02.920 --> 0:18:06.359 what we know is that it's incomplete, and that suggests 0:18:06.359 --> 0:18:10.040 that aliens who might evolve in different circumstances and have 0:18:10.080 --> 0:18:13.439 different needs, could develop a different set of senses. And 0:18:13.520 --> 0:18:16.359 even here on Earth we see a vast diversity of 0:18:16.440 --> 0:18:18.119 senses among the animals. 0:18:18.359 --> 0:18:21.359 That's exactly right, and in fact, in nineteen eleven this 0:18:22.280 --> 0:18:26.280 Baltic physiologists suggested this idea of the umveldt, which is, 0:18:26.560 --> 0:18:29.320 as I mentioned, this idea of what are the signals 0:18:29.320 --> 0:18:32.000 that you're picking up on from around you. So, for example, 0:18:32.000 --> 0:18:34.720 in the world of the tick, it's just picking up 0:18:34.720 --> 0:18:36.679 on temperature and uteric acid. 0:18:36.680 --> 0:18:39.800 That's all it picks up on. For the black. 0:18:39.560 --> 0:18:41.879 Ghost knife fish as it's called, it's just picking up 0:18:41.880 --> 0:18:46.840 on perturbations and electrical fields. For the blind echo locating bat, 0:18:46.840 --> 0:18:50.440 it's picking up on air compression waves returning to it. 0:18:50.800 --> 0:18:51.280 And so the. 0:18:51.320 --> 0:18:55.920 Question is would you develop parallel physics if you had 0:18:55.920 --> 0:18:58.320 a very different umvelt And obviously we can point at 0:18:58.359 --> 0:19:01.800 the creatures on Earth, but let's imagine there are dark 0:19:01.880 --> 0:19:07.200 matter civilizations that are living in dark matter and living 0:19:07.280 --> 0:19:09.240 right next to us, but we can't see them, and 0:19:09.280 --> 0:19:12.120 they can't see us. That's your question is would they 0:19:12.119 --> 0:19:14.600 be asking the same kind of questions are entirely different ones. 0:19:15.359 --> 0:19:17.399 Yeah, it's a great question, you know, sort of an 0:19:17.400 --> 0:19:19.679 extension of the famous philosophical question like what is it 0:19:19.720 --> 0:19:21.679 like to be about? Now we're asking what would it 0:19:21.760 --> 0:19:23.960 like to be like to be an alien physicist? And 0:19:24.040 --> 0:19:29.600 it matters because we can extend our sensations technologically, like 0:19:29.720 --> 0:19:32.560 we develop infrared sensors and we develop sensors that can 0:19:32.600 --> 0:19:34.640 detect neutrinos. 0:19:34.080 --> 0:19:34.520 Et cetera. 0:19:34.920 --> 0:19:37.840 But in the end, we're always translating it back into 0:19:37.840 --> 0:19:41.040 the language we find intuitive. The job of physics, of 0:19:41.119 --> 0:19:43.879 human physics, at least, is to take the unfamiliar and 0:19:43.960 --> 0:19:47.879 make it familiar. Think about how we describe photons. Photons 0:19:47.880 --> 0:19:50.840 are something new and weird and quantum will never fully grasp, 0:19:51.400 --> 0:19:54.480 but we describe them in terms of intuitive concepts that 0:19:54.520 --> 0:19:56.400 make sense to us. We say, oh, it's a particle, 0:19:56.440 --> 0:19:58.920 it's a wave, it's somehow a weird combination of both. 0:19:59.000 --> 0:20:01.680 The reality is it's either it's something new and bizarre 0:20:02.000 --> 0:20:04.720 and we're struggling to understand it because we insist on 0:20:04.880 --> 0:20:08.400 doing this translation back into something that's intuitive. For us, 0:20:08.840 --> 0:20:11.760 and I think that our sensations are sensorium, the senses 0:20:11.800 --> 0:20:15.440 we used to interact with the universe determine what's intuitive 0:20:15.480 --> 0:20:17.600 to us. You know, when I think about answering the 0:20:17.680 --> 0:20:21.520 question like how is the orbit of Saturn affecting this 0:20:21.680 --> 0:20:24.879 or that, I'm thinking geometrically, I'm thinking visually. I'm thinking 0:20:24.920 --> 0:20:28.520 spatially because that's the way my brain works. So now 0:20:28.560 --> 0:20:32.560 imagine an alien and maybe these aliens are microscopic, and 0:20:32.600 --> 0:20:35.480 so they have some sort of quantum senses that are 0:20:35.640 --> 0:20:38.760 natural and intuitive to them. Maybe they can see photons 0:20:38.800 --> 0:20:43.520 in superposition without collapsing them, And so to them, what's intuitive, 0:20:43.560 --> 0:20:45.800 what makes sense? The language they want to translate the 0:20:45.880 --> 0:20:50.360 universe into could be vastly different, and their explanations might 0:20:50.520 --> 0:20:53.040 make no sense to us, and ours might be very 0:20:53.040 --> 0:20:55.520 confusing to them. And so I think the question and 0:20:55.560 --> 0:20:59.720 perception not just determines what you initially see, but ultimately 0:21:00.240 --> 0:21:02.720 it's the language you used to express yourself what it's 0:21:02.920 --> 0:21:05.960 like to be a human or an alien physicist in 0:21:06.000 --> 0:21:06.680 the universe. 0:21:06.920 --> 0:21:09.520 So I love that, And what it reminds me of 0:21:09.600 --> 0:21:11.800 is an idea that I've been writing about lately, which 0:21:11.840 --> 0:21:14.680 is umvelt hacking, which is a term I first searched 0:21:14.680 --> 0:21:17.840 from my friend Eric Weinstein. But the idea of umbelt 0:21:17.840 --> 0:21:19.959 hacking is just that we take things that, for example, 0:21:19.960 --> 0:21:23.439 are very small, and we expand them so that we 0:21:23.480 --> 0:21:26.480 can see them. Or we take let's say, light that 0:21:26.520 --> 0:21:29.919 we cannot see, like ultraviolet and infrared, and we translated 0:21:30.080 --> 0:21:31.359 into what we can see. 0:21:31.480 --> 0:21:32.800 So we're constantly taking. 0:21:32.560 --> 0:21:35.639 Everything that we're discovering in the universe and translating it 0:21:35.680 --> 0:21:38.480 to the little window that we can perceive directly. But 0:21:38.520 --> 0:21:41.480 what you're suggesting is is even the step just beyond that, 0:21:41.560 --> 0:21:44.879 which is what is intuitive to us, like what can 0:21:44.920 --> 0:21:48.359 we even understand? So we take photons and translate them 0:21:48.359 --> 0:21:51.560 into a little story that makes sense to us. 0:21:52.400 --> 0:21:54.879 Or think about like gravitational waves. When they were discovered, 0:21:55.400 --> 0:21:58.320 they were described as sound waves, like we know they're 0:21:58.359 --> 0:22:02.200 not sound waves, there's no compression waves, but they're called chirps, 0:22:02.240 --> 0:22:05.240 and they were translated into literal little sounds. 0:22:04.920 --> 0:22:05.480