WEBVTT - Is physics discovered or invented? 0:00:07.840 --> 0:00:12.160 Imagine the day the Aliens finally arrive. Maybe you're picturing 0:00:12.320 --> 0:00:17.360 an invasion, ramps dramatically unfolding from gleaming ships, snarling tentacled 0:00:17.400 --> 0:00:22.000 monsters slithering down rapidly, overrunning Earth's meager defenses. And yet 0:00:22.200 --> 0:00:26.120 that's fair. We're as likely to be unceremoniously fried into 0:00:26.200 --> 0:00:29.400 human crisps by a planet wide death ray as anything else. 0:00:30.040 --> 0:00:34.720 But this is seeing the alien arrival glass as half empty. Instead, 0:00:35.000 --> 0:00:37.479 let's look at the glass as half full, even if 0:00:37.520 --> 0:00:41.479 we aren't sure yet what it's full of. Maybe aliens 0:00:41.479 --> 0:00:44.760 have figured out the answers to puzzles that remain impenetrable 0:00:44.800 --> 0:00:47.680 to us, like what everything is made out of at 0:00:47.720 --> 0:00:51.319 the smallest level, or why time only flows forward, or 0:00:51.520 --> 0:00:54.920 how big the universe is. What if aliens know for 0:00:55.000 --> 0:00:57.840 a fact how our universe began and how it all 0:00:57.920 --> 0:01:00.640 might end. What if they know what it's like inside 0:01:00.640 --> 0:01:03.960 a black hole, or actually understand quantum mechanics like the 0:01:03.960 --> 0:01:07.360 back of their tentacle. Maybe to them, the universe isn't 0:01:07.440 --> 0:01:11.040 a place of consistent mystery, but one that tindly follows 0:01:11.040 --> 0:01:14.039 some basic rules. And what if they could just tell 0:01:14.120 --> 0:01:16.920 us how everything works? So we don't have to blindly 0:01:17.000 --> 0:01:20.839 hack away for decades or centuries to gain this elusive knowledge. 0:01:20.959 --> 0:01:24.000 They might carry the product of millions or billions of 0:01:24.120 --> 0:01:28.240 years of alien scientific thought to catapult us unimaginably far 0:01:28.400 --> 0:01:32.319 in our quest to understand this wonderful, bizarre, violent, and 0:01:32.400 --> 0:01:36.920 beautiful cosmos. If our species met up, physicists hope that 0:01:36.959 --> 0:01:39.640 we'd be able to geek out together, sharing notes on 0:01:39.760 --> 0:01:44.280 this glorious galactic journey of discovery. But could that really happen. 0:01:44.720 --> 0:01:48.640 A lot of scientists, especially physicists, believe it. Could. They 0:01:48.680 --> 0:01:51.800 imagine that unraveling the secrets of nature is a universal 0:01:51.880 --> 0:01:54.560 project that would be shared by the scientists of alien 0:01:54.640 --> 0:01:58.880 species across the galaxy, and that physics describes everything in 0:01:58.920 --> 0:02:01.760 the universe, not just life on Earth, and so should 0:02:01.800 --> 0:02:05.639 also form the foundation of alien science. Therefore, we should 0:02:05.640 --> 0:02:08.400 be able to use physics as a mental bridge between 0:02:08.440 --> 0:02:12.280 our species. But hold on a second. Are we accepting 0:02:12.280 --> 0:02:15.639 those arguments too quickly? Have we really given the question 0:02:15.880 --> 0:02:19.080 careful thought? Or are we blinded by our fantasy of 0:02:19.120 --> 0:02:23.639 galactic scientific cooperation and the narrowness of our own experience. 0:02:24.120 --> 0:02:27.520 We have only our one example of science here on Earth, 0:02:27.600 --> 0:02:30.120 so it's hard to be sure how much of it 0:02:30.200 --> 0:02:34.000 might be colored by human nature and culture. Are human 0:02:34.040 --> 0:02:36.120 physics and math the only way to think about the 0:02:36.240 --> 0:02:38.960 universe or are they just the only way we can 0:02:39.000 --> 0:02:42.640 imagine it. Are the laws of physics something universal, something 0:02:42.680 --> 0:02:46.520 we have discovered, or are the human something we have invented. 0:02:47.320 --> 0:02:51.200 Welcome to Daniel and Kelly's Extraordinary Alien Universe. 0:03:04.440 --> 0:03:05.359 Hello. I'm Kelly. 0:03:05.400 --> 0:03:08.280 I study parasites and space, but I don't think about 0:03:08.320 --> 0:03:09.720 aliens as much as Daniel does. 0:03:10.320 --> 0:03:10.480 Hi. 0:03:10.560 --> 0:03:12.799 I'm Daniel. I'm a particle physicist, and I do want 0:03:12.800 --> 0:03:15.480 to figure out the secrets of the universe myself, but 0:03:15.520 --> 0:03:18.799 I'd rather just download them from alien brains if possible. 0:03:18.960 --> 0:03:19.920 Yeah, that'd be nice, all right. 0:03:19.960 --> 0:03:23.359 So my question for you, Daniel, when you think about aliens, 0:03:23.360 --> 0:03:25.320 which is apparently all the. 0:03:25.280 --> 0:03:28.760 Time, embarrassingly high fraction in my brain? 0:03:28.840 --> 0:03:29.800 Yes, that's right. That's right. 0:03:29.840 --> 0:03:32.480 For someone who's not like a conspiracy theorist or a 0:03:32.520 --> 0:03:35.600 cryptid fan, you think about them a lot. 0:03:36.240 --> 0:03:37.640 You're making some assumptions there. 0:03:37.920 --> 0:03:42.320 I've known you for a while, But when you imagine aliens, 0:03:43.320 --> 0:03:44.960 what do they look like in your head? 0:03:45.360 --> 0:03:50.280 Oh? Boy? Wow? You know I think it's almost impossible 0:03:50.320 --> 0:03:53.440 to anticipate what aliens actually look like, or at least 0:03:53.440 --> 0:03:56.360 I hope. So you know this two scenarios. One is 0:03:56.520 --> 0:03:59.320 aliens show up and they're basically star trek, you know, 0:03:59.600 --> 0:04:03.040 they're humans with fuzzy foreheads or you know, just some 0:04:03.400 --> 0:04:05.400 little tweak on the kind of life we have here 0:04:05.480 --> 0:04:08.280 on Earth. The other scenario is they show up and 0:04:08.320 --> 0:04:12.440 they're so much weirder than we could ever possibly imagine, 0:04:12.920 --> 0:04:15.080 And that, to me is the fascinating scenario. That's the 0:04:15.120 --> 0:04:18.320 non Starbucks scenario. You know, it's like, you don't want 0:04:18.320 --> 0:04:21.400 to travel the world and discover Starbucks on every corner. 0:04:21.440 --> 0:04:25.000 That's boring. You have Starbucks at home, says you. I mean, 0:04:25.040 --> 0:04:29.120 I like Starbucks too, but I prefer like local, weird coffee. 0:04:29.680 --> 0:04:32.760 That's why I go traveling. And so if aliens show 0:04:32.880 --> 0:04:35.120 up and they're not really weird, I'm going to be 0:04:35.120 --> 0:04:36.480 disappointed in the universe. 0:04:36.720 --> 0:04:39.200 Quick side note, When I travel, I do like to 0:04:39.240 --> 0:04:42.520 go to the McDonald's and other countries because but only 0:04:42.560 --> 0:04:44.640 because I like to see what other stuff they have 0:04:44.720 --> 0:04:46.800 on their menus, you know, because they usually don't have 0:04:46.880 --> 0:04:49.480 like the US standard menu, and I like to see like, oh, 0:04:49.480 --> 0:04:53.800 what's the how did McDonald's homogenize with this culture to 0:04:54.000 --> 0:04:58.280 create something new? But also confession time, Zach and I 0:04:58.400 --> 0:05:01.240 were in Versailles for our honey and we had this 0:05:01.520 --> 0:05:04.960 lovely breakfast and we went to go throw away our 0:05:05.000 --> 0:05:09.320 receipt in our trash and I noticed a McDonald's arch 0:05:10.080 --> 0:05:12.440 and I was like, wait a minute, and it was 0:05:12.520 --> 0:05:14.720 it looked so nice. We didn't realize we had gotten 0:05:14.760 --> 0:05:18.480 breakfast at McDonald's on our honeymoon and it was delicious. 0:05:18.560 --> 0:05:19.559 We had a great time. 0:05:19.760 --> 0:05:22.159 In your defense, McDonald's in France is really a different 0:05:22.200 --> 0:05:25.840 kind of thing. Yeah, it really is much more upscale, absolutely. 0:05:25.360 --> 0:05:27.520 Well, and that's like a cultural insight or something that 0:05:27.760 --> 0:05:29.720 I feel like you get by visiting the McDonald's. But 0:05:30.000 --> 0:05:32.520 anyway else I don't exclusively eat at McDonald's. 0:05:33.400 --> 0:05:36.080 Well. I went to a conference in TYPEI once with 0:05:36.120 --> 0:05:39.400 an Israeli colleague and he ate every single meal at 0:05:39.480 --> 0:05:43.279 Subway or McDonald's and like, this is Type AI people. 0:05:43.360 --> 0:05:46.000 I mean, the food there is incredible. I was a 0:05:46.080 --> 0:05:48.719 vegetarian at the time and we had this nineteen course 0:05:48.800 --> 0:05:53.000 banquet dinner and they served me a separate, different vegetarian thing. 0:05:53.120 --> 0:05:55.600 For each of the nineteen courses, and each one blew 0:05:55.640 --> 0:05:58.320 my mind, Like the food there is unbelievable. Plus I 0:05:58.320 --> 0:06:00.520 also went to the night market and like all sorts 0:06:00.520 --> 0:06:02.760 of weird stuff that probably had eyeballs in it. But 0:06:02.800 --> 0:06:04.359 to me, that was the joy of it, right. But 0:06:04.400 --> 0:06:06.320 he was like, yeah, no, I'm not touching that. 0:06:07.839 --> 0:06:08.279 But hold on. 0:06:08.279 --> 0:06:10.680 If you're a vegetarian but you eat eyeballs, is that 0:06:10.720 --> 0:06:14.680 like an eyebolitarian like a pesetarian only eats fish. 0:06:14.760 --> 0:06:16.440 Well, I was a vegetarian at the time, but I 0:06:16.480 --> 0:06:18.280 also wanted to explore, and I was at the night 0:06:18.320 --> 0:06:20.280 market and I couldn't speak the language, so I took 0:06:20.320 --> 0:06:22.320 some risks. And I'm not sure whether or not I 0:06:22.440 --> 0:06:25.839 ate eyeballs. I think probability Daniel ate eyeballs that evening 0:06:25.960 --> 0:06:26.680 fifty percent. 0:06:26.800 --> 0:06:29.560 Yeah, good, good on you. It's good to try new awesome. 0:06:30.440 --> 0:06:31.480 Yeah. 0:06:31.800 --> 0:06:34.479 Anyway, the joy of traveling is exploring the universe and 0:06:34.520 --> 0:06:37.360 having your mind blown by how surprising it is, by 0:06:37.400 --> 0:06:39.919 breaking out of the box of your expectations. 0:06:40.160 --> 0:06:43.880 Absolutely, and you always are so great at transitioning us home. 0:06:44.080 --> 0:06:46.159 And so here we are today. 0:06:46.200 --> 0:06:49.039 We're talking about the joy of studying physics and we're 0:06:49.040 --> 0:06:52.800 trying to nail down on the philosophical question. Is physics 0:06:52.920 --> 0:06:55.240 discovered or invented? 0:06:55.520 --> 0:06:58.000 Yeah, exactly, it's the physics that we have developed here 0:06:58.000 --> 0:07:01.479 on Earth. Are we figuring out basic rules of the universe? 0:07:01.839 --> 0:07:04.640 Or are we just telling a human story one that's 0:07:04.680 --> 0:07:07.920 approximate and effective and kind of only makes sense to us. 0:07:08.480 --> 0:07:11.760 And this is a philosophical question for sure, but I 0:07:11.880 --> 0:07:14.280 like to think about it in concrete terms and inject 0:07:14.360 --> 0:07:17.840 aliens into it by imagining the scenario that aliens arrive 0:07:18.000 --> 0:07:20.560 and we try to talk to them about this because 0:07:20.720 --> 0:07:23.240 that's when it matters, right, And might think who cares 0:07:23.320 --> 0:07:27.400 if it's discovered or invented, it works, right, But number one, 0:07:27.520 --> 0:07:31.280 I'm curious about whether it's really deeply true. And also 0:07:31.440 --> 0:07:34.080 I am concerned about this situation. What if aliens show 0:07:34.120 --> 0:07:36.160 up and they have these answers but we can't make 0:07:36.200 --> 0:07:38.920 a scientific connection with them. That would be so frustrating. 0:07:38.960 --> 0:07:41.760 And that's why I wrote my new book, Do Aliens 0:07:41.840 --> 0:07:45.880 Speak Physics? Out November fourth from Norton and available at 0:07:45.880 --> 0:07:48.440 all fine bookstores. Please go check it out. 0:07:48.600 --> 0:07:50.680 Okay, so you said that it would be a real 0:07:50.720 --> 0:07:54.040 bummer if the aliens got here and we, like you know, 0:07:54.200 --> 0:07:57.280 hadn't figured out the truth. Is that because you're worried 0:07:57.280 --> 0:07:59.400 about what they're gonna think of us, In which case 0:07:59.400 --> 0:08:01.360 I have a speed that I tell my daughter about 0:08:01.440 --> 0:08:04.440 why you shouldn't worry about what other people think. Or 0:08:04.560 --> 0:08:08.000 is it because it would inhibit our ability to communicate? 0:08:08.560 --> 0:08:12.280 In that case, my fantasy is that the aliens deliver 0:08:12.440 --> 0:08:15.320 to us answers to some of the puzzles, you know, 0:08:15.480 --> 0:08:18.200 like I just want to know what is inside a 0:08:18.200 --> 0:08:21.000 black hole? What is the real story of the universe. 0:08:21.520 --> 0:08:23.840 I would love to know the answers to these questions. 0:08:24.080 --> 0:08:26.880 And the idea that aliens have these answers out there 0:08:27.080 --> 0:08:29.760 is endlessly frustrating to me. If they could just show 0:08:29.840 --> 0:08:31.840 up and give them to us, you know, like somebody 0:08:31.840 --> 0:08:34.000 knows the truth, please just share it with us. So 0:08:34.480 --> 0:08:37.319 my concern is that they show up and we're mismatched 0:08:37.360 --> 0:08:40.520 somehow so that we can't get those answers. Maybe we're 0:08:40.559 --> 0:08:43.200 not smart enough to understand it, or maybe we're going 0:08:43.240 --> 0:08:45.560 down a different path, or maybe they have a different 0:08:45.559 --> 0:08:49.360 way of explaining these things, or maybe they're asking different questions, 0:08:49.360 --> 0:08:51.520 you know, they perceive the universe differently. And they're not 0:08:51.600 --> 0:08:55.360 interested in the questions we're asking, and so I'm worried 0:08:55.400 --> 0:08:58.520 about these scenarios where we're mismatched with the aliens, and 0:08:58.559 --> 0:09:01.880 so we can't have that moment of scientific cross emogenation. 0:09:02.559 --> 0:09:04.600 I mean, do you think it's possible that we're on 0:09:04.679 --> 0:09:07.960 the right track and they're not, or if they get 0:09:08.000 --> 0:09:10.360 to us, then they must be on the right track 0:09:10.400 --> 0:09:11.680 because they're doing stuff we can't. 0:09:11.760 --> 0:09:14.520 That's a great question. I think if we're on different tracks, 0:09:14.600 --> 0:09:17.440 that probably says something about the nature of the universe. 0:09:17.679 --> 0:09:21.200 If he can be described in different ways, then maybe 0:09:21.280 --> 0:09:24.240 there is no one truth and you can't say who's 0:09:24.240 --> 0:09:25.839 on the right track or the wrong track. 0:09:25.920 --> 0:09:28.360 Well, when I'm interested in finding the truth, what I 0:09:28.440 --> 0:09:30.440 do is I reach out to the extraordinaries. 0:09:30.480 --> 0:09:31.680 And so that's what we did. 0:09:32.360 --> 0:09:35.280 We reached out to our listeners and we asked, are 0:09:35.320 --> 0:09:38.360 the laws of physics discovered or invented? 0:09:38.720 --> 0:09:42.160 I think that lots of physics are somewhere in between 0:09:42.280 --> 0:09:44.600 an invention and discovery. 0:09:45.240 --> 0:09:47.720 Maybe closer to the discovery I will help. 0:09:47.920 --> 0:09:51.360 And Einstein didn't invent space time doing its bendy, squishy, 0:09:51.400 --> 0:09:54.040 stretchy thing. He just caught it in the act, so 0:09:54.320 --> 0:09:55.559 definitely discovered. 0:09:55.800 --> 0:09:58.400 Our curiosity and need to understand the world around us 0:09:58.400 --> 0:10:00.920 has led us to discover the laws of physics, and 0:10:00.960 --> 0:10:03.000 we've had to invent tools to help us do that, 0:10:03.400 --> 0:10:06.240 both abstract and physical. So it's a little bit of both. 0:10:06.559 --> 0:10:07.800 It seems it's some of both. 0:10:08.000 --> 0:10:10.800 There are realities in the universe that we can discover, 0:10:11.160 --> 0:10:15.640 and then we invent models to describe those realities. 0:10:15.880 --> 0:10:20.760 Surely the laws of physics discovered because they already exist. 0:10:21.080 --> 0:10:24.120 I think they are discovered. I think it's a little 0:10:24.120 --> 0:10:26.839 bit of both. I think they're invented as we're kind 0:10:26.840 --> 0:10:29.400 of putting the bits and pieces together, and then the 0:10:29.440 --> 0:10:32.520 more we can understand it, the more we are discovering 0:10:32.559 --> 0:10:33.880 how things actually are. 0:10:34.080 --> 0:10:36.720 So the laws of physics are certainly discovered, while the 0:10:36.760 --> 0:10:39.600 maths used to describe them, or human inventions. 0:10:39.760 --> 0:10:44.239 The laws of physics are of course discovered, but defined 0:10:44.679 --> 0:10:48.000 in our language as humans and correct. 0:10:48.320 --> 0:10:52.200 It's discovered, Otherwise it's invented because it's not correct. It 0:10:52.240 --> 0:10:54.560 doesn't seem to make sense to me to say that 0:10:55.520 --> 0:10:57.920 we invented gravitying. 0:10:58.160 --> 0:11:01.320 I would say that the way things are is discovered, 0:11:01.559 --> 0:11:03.960 but the methodology by which we use to measure and 0:11:04.040 --> 0:11:07.079 categorize in our own terms is invented, but. 0:11:07.040 --> 0:11:09.559 The laws of physics help us make order and meaning 0:11:09.640 --> 0:11:12.640 from what we discover. But they're not immutable, so in 0:11:12.640 --> 0:11:15.760 that sense they're invented and can change as new things 0:11:15.800 --> 0:11:18.760 are discovered. I would say, while the fundamental mechanisms how 0:11:18.760 --> 0:11:22.360 physics work are discovered, the laws of physics are invented. 0:11:22.640 --> 0:11:25.120 They are useful and necessary for set mechanisms to make 0:11:25.120 --> 0:11:26.440 sense to our big monkey brains. 0:11:26.600 --> 0:11:29.320 I think the observations of the universe are constant, but 0:11:29.559 --> 0:11:33.200 how we describe them as laws depends on our particular 0:11:33.720 --> 0:11:36.160 moment in history and the mathematics available to us at 0:11:36.200 --> 0:11:36.559 the time. 0:11:36.720 --> 0:11:38.200 I think they were both. I think the laws of 0:11:38.200 --> 0:11:41.280 physics were first discovered and then we invented the mathod 0:11:41.320 --> 0:11:42.560 to goal with what we discovered. 0:11:42.720 --> 0:11:45.960 The laws of physics must be fundamental and the way 0:11:46.000 --> 0:11:49.000 we do Oh, there goes the dog, and we discover 0:11:49.080 --> 0:11:53.200 it by doing inventions, and that was the dog participating. 0:11:53.320 --> 0:11:55.559 I hope the dog was right. These are such great, 0:11:55.559 --> 0:11:58.720 thoughtful answers. Not surprised, of course, but impressed. 0:11:58.920 --> 0:12:01.319 When I started researching a city on Mars, one of 0:12:01.400 --> 0:12:03.680 the things that I loved was that people would say, Oh, 0:12:03.880 --> 0:12:05.960 obviously X is the case, and then you'd go and 0:12:06.000 --> 0:12:08.120 talk to the next group and they'd be like, obviously, 0:12:08.200 --> 0:12:10.800 why is the case? I think the most common version 0:12:10.800 --> 0:12:14.040 for me was obviously we can't settle space right now. 0:12:14.080 --> 0:12:16.200 And then other people would be like, obviously we're ready 0:12:16.240 --> 0:12:17.679 to do it right now, and I'd be like, oh, 0:12:17.720 --> 0:12:20.040 my goodness, how can everybody be so sure? But anyway, 0:12:20.360 --> 0:12:21.880 so we've got a nice mix of answers. 0:12:22.080 --> 0:12:24.680 I love those moments because then you get to dig 0:12:24.720 --> 0:12:28.079 into the assumptions that are leading you there and open 0:12:28.080 --> 0:12:30.560 people's mind. So hold on a second. That's an assumption 0:12:30.640 --> 0:12:33.280 that's not something you know, and maybe it feels natural 0:12:33.320 --> 0:12:36.280 to you, it feels intuitive, But do you have data? 0:12:36.400 --> 0:12:39.200 Do you have one of the reasons for holding those assumptions. 0:12:39.320 --> 0:12:41.640 Those are the moments when your mind expands, right when 0:12:41.679 --> 0:12:44.440 you're like, oh, wait, maybe eyeballs are a good snack 0:12:44.520 --> 0:12:45.160 after all, you know. 0:12:45.200 --> 0:12:46.640 I feel like at the top of my list of 0:12:46.720 --> 0:12:50.120 people that I want to correct me is you, because 0:12:50.760 --> 0:12:53.719 when you're like, you know, when what you mean is well, 0:12:53.720 --> 0:12:55.760 that sounds kind of wrong. Instead it sounds like an 0:12:55.760 --> 0:12:59.000 amazing philosophical insight, and I'm like, oh, that's such a 0:12:59.000 --> 0:13:01.000 cool way to think about and then afterwards you're like, 0:13:01.120 --> 0:13:02.760 wait a minute, Daniel told me I'm wrong. 0:13:03.800 --> 0:13:06.080 You know. That's my process with students and actually with 0:13:06.120 --> 0:13:08.880 podcast listeners. They often come to me with a question 0:13:09.000 --> 0:13:12.199 and the question doesn't really make sense or and it 0:13:12.520 --> 0:13:15.760 makes me realize they've absorbed some piece of information that's 0:13:15.800 --> 0:13:17.800 wrong and that's led them down this path. And so 0:13:18.080 --> 0:13:20.400 I feel like the job of a teacher is not 0:13:20.480 --> 0:13:22.560 to say you're wrong, here's the right answer, but to 0:13:22.679 --> 0:13:25.160 unravel their thought process to the moment they took the 0:13:25.200 --> 0:13:27.439 wrong path and show them the right way to go. 0:13:27.559 --> 0:13:29.240 Yeah, And that's one of the reasons I like working 0:13:29.280 --> 0:13:30.920 with you so much, because I feel like you're an 0:13:30.960 --> 0:13:33.360 easy person to throw ideas out at because you're not 0:13:33.400 --> 0:13:36.400 going to be told, well, that was stupid. So anyway, 0:13:36.440 --> 0:13:40.840 all right, our listeners are amazing. Let's jump into what 0:13:40.880 --> 0:13:44.280 does this question even mean? What assumptions are in that question? 0:13:44.520 --> 0:13:46.760 I think a lot of people might hear this question, 0:13:46.920 --> 0:13:49.079 especially a lot of people in physics, and say, well, 0:13:49.120 --> 0:13:52.080 of course, the laws of physics are something we're discovering, 0:13:52.160 --> 0:13:55.000 because there's something real happening out there in the universe, 0:13:55.320 --> 0:13:58.439 and we have this process of science for slowly deducing 0:13:58.480 --> 0:14:01.880 the truth, and you know, we use mathematics to express 0:14:01.920 --> 0:14:04.040 it and it just works so well, and so I 0:14:04.080 --> 0:14:06.839 think it's the natural point of view. The place people 0:14:06.880 --> 0:14:10.679 often start is that, Okay, physics is something we're figuring 0:14:10.720 --> 0:14:14.120 out about the universe, and lots of physicists feel that. 0:14:14.160 --> 0:14:16.679 I remember talking to string theorist Thomas van Reet and 0:14:16.720 --> 0:14:19.120 he was like, yes, aliens will be doing string theory. 0:14:19.280 --> 0:14:23.280 I don't even doubt it. His confidence was amazing. Yep, 0:14:23.320 --> 0:14:25.600 I love that, and there's reasons for that. It's not 0:14:25.640 --> 0:14:27.920 an unreasonable point of view, but it's also not the 0:14:27.960 --> 0:14:30.840 only point of view. And you know, this question is 0:14:30.840 --> 0:14:35.760 similar to another, maybe more widely discussed question in philosophy 0:14:35.760 --> 0:14:39.040 and in popular discussion, which is about mathematics. Right, is 0:14:39.120 --> 0:14:44.200 mathematics invented or discovered? And here mathematics is the language 0:14:44.240 --> 0:14:46.760 of science, and so it's natural to ask, like, well, 0:14:47.080 --> 0:14:50.280 is mathematics like our mental shorthand for the way the 0:14:50.360 --> 0:14:53.720 universe works? Or is it some part of the universe? 0:14:53.760 --> 0:14:57.840 Did the concept of seven exist before there are humans, 0:14:58.320 --> 0:15:00.480 you know? Or is it something that we came up 0:15:00.520 --> 0:15:03.760 with to help explain the universe around us. You know, 0:15:03.800 --> 0:15:06.160 I think a way to sum up the question essentially, 0:15:06.200 --> 0:15:09.560 is is physics the map or is it the territory? 0:15:09.600 --> 0:15:12.240 Are we describing something that's happening out there in the 0:15:12.320 --> 0:15:15.160 universe or are we revealing the actual truth? 0:15:15.400 --> 0:15:16.640 So could you give me an example? 0:15:16.680 --> 0:15:19.040 Like, all right, so say you've got a theory and 0:15:19.520 --> 0:15:22.720 you make some observations and the observations matches what you 0:15:22.760 --> 0:15:26.280 would expect from the theory, Bing bamboom, You've got it right, 0:15:26.320 --> 0:15:28.800 And so like, why is that not sufficient? 0:15:29.120 --> 0:15:31.600 Yeah, that's a great question. If you have a bunch 0:15:31.600 --> 0:15:33.480 of data and you have a theory that describes that, 0:15:33.560 --> 0:15:37.520 there's always another theory that also fits that data, right, 0:15:37.640 --> 0:15:39.960 because you don't have infinite data, and you could have 0:15:39.960 --> 0:15:43.520 two theories that deviate between the two data points. Or 0:15:43.560 --> 0:15:46.760 for example, I could just take our current theory and say, 0:15:47.080 --> 0:15:49.840 here's another theory that also describes the universe. It's exactly 0:15:49.840 --> 0:15:52.640 the same, but it predicts that in one hundred years 0:15:53.000 --> 0:15:56.320 electrons will lose their charge. I mean that theory perfectly 0:15:56.360 --> 0:16:00.360 describes all of our experiments. It's sort of ridiculous reason 0:16:00.400 --> 0:16:03.240 to believe in is obviously has this added twist to 0:16:03.280 --> 0:16:05.200 it that you don't need, and you can use outcomes 0:16:05.280 --> 0:16:07.400 razor to reject it. But it's just an example of 0:16:07.440 --> 0:16:11.000 how there are always more theories that do describe the data, 0:16:11.440 --> 0:16:13.400 and so you can't be guaranteed just by having a 0:16:13.440 --> 0:16:16.040 theory that matches your data that it's the only theory, 0:16:16.200 --> 0:16:18.000 or even that it's the true theory. 0:16:18.160 --> 0:16:20.600 Yeah, I mean, could there be like some intermediate between 0:16:20.680 --> 0:16:24.520 your theory and the observation that wasn't incorporated in some way, 0:16:24.560 --> 0:16:26.840 Like you think that X causes why, but actually there's 0:16:26.880 --> 0:16:29.960 a Z that's interacting there that wasn't in your theory 0:16:30.000 --> 0:16:32.760 at all, and that would change predictions in another environment 0:16:32.920 --> 0:16:33.640 or something. 0:16:33.520 --> 0:16:35.800 Exactly, because perhaps you only have data in a certain 0:16:35.840 --> 0:16:39.000 set of circumstances, right, and you haven't seen the wider picture. 0:16:39.040 --> 0:16:41.040 For example, for hundreds of years, we thought Newton was 0:16:41.120 --> 0:16:44.520 right about gravity, and his theory bore out every single 0:16:44.600 --> 0:16:47.440 test we did until we pushed the boundaries and we 0:16:47.480 --> 0:16:50.080 started looking at really high speed events and you know, 0:16:50.080 --> 0:16:53.280 the orbit of mercury and tiny little details. Only then 0:16:53.400 --> 0:16:56.000 was it revealed that Newton's theory wasn't as accurate as 0:16:56.000 --> 0:16:58.360 we thought, and in fact the whole story that it 0:16:58.440 --> 0:17:02.200 was telling, right and forces between them, that story is 0:17:02.240 --> 0:17:04.560 not the story of what's really happening in the universe. 0:17:04.640 --> 0:17:07.840 Now we have another story, Einstein's story of curvature and 0:17:07.920 --> 0:17:11.639 space time. Right, the two agree almost always in our experience, 0:17:11.720 --> 0:17:13.960 but they tell a very very different story about what's 0:17:14.040 --> 0:17:18.159 really happening behind the curtains. And that's philosophically sort of 0:17:18.560 --> 0:17:20.760 scary because it tells you that you could have a 0:17:20.800 --> 0:17:24.080 theory that describes almost everything you see in the universe, 0:17:24.200 --> 0:17:26.919 but it could be telling the wrong story about reality. 0:17:27.440 --> 0:17:29.720 And when the aliens show up and they're like, what, 0:17:29.720 --> 0:17:32.600 what are you guys talking about? That's nonsense. Here's what's 0:17:32.680 --> 0:17:33.520 really going on. 0:17:34.040 --> 0:17:37.159 Okay, But so let's imagine a world where and heaven forbid, 0:17:37.160 --> 0:17:39.919 this is the case where we never meet aliens, Like, 0:17:40.200 --> 0:17:43.480 I know, I'm so sorry, I'm so sorry. Would it 0:17:43.600 --> 0:17:47.120 still matter, Like, if we've got predictions and we can 0:17:47.240 --> 0:17:49.760 use those to make new technologies, does it matter if 0:17:49.800 --> 0:17:51.800 we actually are right or not, or if we've just 0:17:51.840 --> 0:17:54.120 figured out a way to understand the world that's helpful. 0:17:54.280 --> 0:17:56.600 Yeah, great question. I think it depends on what's important 0:17:56.640 --> 0:17:59.359 to you. If what's important to you is, let's build 0:17:59.400 --> 0:18:03.720 cool technology and you know, self driving toothbrushes and whatever, 0:18:04.040 --> 0:18:07.600 then it doesn't really matter, right. But if your goal 0:18:07.960 --> 0:18:11.440 is to reveal something true about the universe to understand, 0:18:11.520 --> 0:18:14.399 and I think in the end that's what physics is about. 0:18:14.480 --> 0:18:18.320 Fundamental physics is a desire to unravel the nature of 0:18:18.359 --> 0:18:21.760 the universe, not just to build cool gizmos. Then it's 0:18:21.800 --> 0:18:25.000 fundamentally frustrating to think that we're not doing that, that 0:18:25.040 --> 0:18:28.320 we're just telling ourselves a story that works, that we're 0:18:28.320 --> 0:18:31.800 not actually hearing from the oracle and revealing the truth 0:18:31.840 --> 0:18:34.840 of the universe, that we're stuck in Plato's cave, essentially 0:18:35.080 --> 0:18:37.560 just looking at shadows on the wall. Yeah, I think 0:18:37.600 --> 0:18:39.080 that would be fundamentally frustrating. 0:18:39.359 --> 0:18:40.920 Absolutely, Yeah, I'll give you that. 0:18:41.000 --> 0:18:44.240 But you ask a great question because aliens haven't arrived yet, 0:18:44.440 --> 0:18:46.800 and so you might ask, like, well, what progress can 0:18:46.840 --> 0:18:50.320 we make anyway on this question before the aliens show up? 0:18:50.320 --> 0:18:51.639 Do we have to just sit here and wait for 0:18:51.680 --> 0:18:53.520 the aliens to arrive and say like yes or no, 0:18:53.760 --> 0:18:56.560 or see how it works? And so that was sort 0:18:56.600 --> 0:18:58.760 of the struggle I faced trying to write this book, 0:18:58.760 --> 0:19:01.520 it's like, well, how do we make any progress before 0:19:01.560 --> 0:19:04.080 the aliens show up? And it turns out you can, right, 0:19:04.200 --> 0:19:07.320 you can look at the structure of human science and 0:19:07.400 --> 0:19:10.040 you can ask like, well, are there places where the 0:19:10.119 --> 0:19:13.760 choices we've made are arbitrary? Or are there things that 0:19:13.800 --> 0:19:16.840 could only have happened this way and in this area. 0:19:16.880 --> 0:19:19.720 I have to give a lot of credit to like biologists, 0:19:20.160 --> 0:19:24.159 because biologists have already done this work. Congratulations, Kelly. You know, 0:19:24.440 --> 0:19:27.879 like biologists have thought about is life on Earth the 0:19:27.960 --> 0:19:29.640 only way it could be? We only have this one 0:19:29.680 --> 0:19:32.879 example of life on Earth, but they've tried their best 0:19:32.880 --> 0:19:35.720 to push beyond the box. For example, they see that 0:19:35.800 --> 0:19:38.359 all life on Earth has carbon as its backbone, but 0:19:38.560 --> 0:19:40.720 that doesn't mean you can assume that all life in 0:19:40.760 --> 0:19:43.480 the universe is carbon based. They imagine ways it could 0:19:43.480 --> 0:19:46.679 have gone differently. Maybe it's silicon in there, right, or 0:19:46.720 --> 0:19:48.600 all life has water in it, but maybe it could 0:19:48.600 --> 0:19:50.600 have had ammonia. So there's been a lot of this 0:19:50.800 --> 0:19:54.520 like push beyond our one example thinking in biology, and 0:19:54.880 --> 0:19:56.840 I wanted to do the same thing for physics, to 0:19:56.920 --> 0:19:59.920