WEBVTT - Is the Universe Random? 0:00:07.800 --> 0:00:11.880 There's a core idea in science that experiments should be repeatable. 0:00:12.080 --> 0:00:14.760 If you do an experiment the same way at different times, 0:00:14.920 --> 0:00:19.680 you should get the same result. However, there is a loophole. 0:00:19.960 --> 0:00:24.520 There's a loophole in science. Yeah, and that loophole opens 0:00:24.520 --> 0:00:28.080 a window into everything we think is true about reality 0:00:28.120 --> 0:00:32.080 and the universe and everything. Doo doo doo doo doo 0:00:32.080 --> 0:00:50.159 doo doo doo doo doo doo. Welcome to Daniel and 0:00:50.240 --> 0:00:52.879 Jorge explain the Universe, in which we try to take 0:00:52.920 --> 0:00:56.000 the entire universe and break it into bite sized pieces 0:00:56.080 --> 0:00:58.840 so you're gonna enjoy them with your afternoon coffee. I'm alright. 0:00:58.840 --> 0:01:02.560 I'm a cartoonist. I draw comics online, and I'm Daniel. 0:01:02.560 --> 0:01:05.839 I'm a particle physicist. I spend my days smashing protons 0:01:05.880 --> 0:01:08.520 together at the Large Hadron Collider to try to reveal 0:01:08.640 --> 0:01:11.000 the secrets of the universe, mostly so that I can 0:01:11.120 --> 0:01:14.319 tell them to you in this podcast. Basically only one 0:01:14.360 --> 0:01:16.720 of us is qualified to be explaining things to you 0:01:17.000 --> 0:01:20.959 on this podcast. That would be the cartoonist business. They're 0:01:21.000 --> 0:01:23.640 not qualified usually to be explainers. Mostly we just try 0:01:23.680 --> 0:01:25.720 to solve the mysteries of the universe. We don't try 0:01:25.720 --> 0:01:29.640 to tell anybody about them, right, Mostly physicists just need explaining, 0:01:30.400 --> 0:01:33.160 that's right, that's where the cartoons come in, right, And 0:01:33.240 --> 0:01:37.120 spouses also, spouses physicist probably have to do a lot 0:01:37.120 --> 0:01:41.479 of explaining. You've got some explaining to do, exactly. Yeah. Um, 0:01:41.560 --> 0:01:43.240 So we're here to talk to you about big questions 0:01:43.280 --> 0:01:46.279 about the universe. And today's question is a really deep 0:01:46.400 --> 0:01:50.160 and basic question, and it's about the very nature of reality. 0:01:50.280 --> 0:01:52.040 What is it? Hory? What are we gonna talk about today? 0:01:54.680 --> 0:01:59.480 Is the universe random or is it just chaotic? And 0:01:59.680 --> 0:02:03.720 what the difference? Or is it run by some super being? 0:02:03.760 --> 0:02:06.040 And we're actually just in their simulation. But that's a 0:02:06.080 --> 0:02:09.040 whole other episode. That's a whole other podcast. Right today, 0:02:09.160 --> 0:02:12.799 just the two sinister options, random or chaotic, you might 0:02:12.840 --> 0:02:14.799 feel like, oh, neither of those sound very cozy. I 0:02:14.840 --> 0:02:17.079 don't want to live in either of those universes. Well, 0:02:17.080 --> 0:02:20.959 the question basically breaks down to is the universe predictable? 0:02:21.120 --> 0:02:23.480 Like can you predict what the universe is going to do? 0:02:23.840 --> 0:02:27.080 Or is it that nobody can predict what the universe 0:02:27.120 --> 0:02:28.919 is going to do? Right? And I think that's why 0:02:28.960 --> 0:02:32.200 It's an awesome question for science because for so many 0:02:32.240 --> 0:02:36.240 thousands and thousands of years, I think humans probably felt 0:02:36.280 --> 0:02:39.120 like the universe around them was totally unpredictable. I mean, 0:02:39.160 --> 0:02:41.600 they invented gods for this and for that to try 0:02:41.639 --> 0:02:44.520 to describe how the universe was out of their control 0:02:44.680 --> 0:02:46.520 and doing things that didn't make sense, as if it 0:02:46.520 --> 0:02:49.880 had some you will and agency. Right, and then science 0:02:49.919 --> 0:02:52.920 comes along it says, actually, there are rules and you 0:02:52.960 --> 0:02:56.200 can discover them. And slowly science starts to creep in 0:02:56.240 --> 0:02:59.400 this description of the universe that locks out this agency, 0:02:59.480 --> 0:03:02.040 this idea of this personality, and gives you the sense 0:03:02.040 --> 0:03:05.560 that maybe the universe follows these rules. Right. So we 0:03:05.600 --> 0:03:08.079 went out and as usually, ask people on the street, 0:03:08.360 --> 0:03:12.920 do you think the universe is random or chaotic? And 0:03:13.000 --> 0:03:16.240 here's what they had to say, that's gonna okay, that's 0:03:16.280 --> 0:03:21.080 a that's a thinker right there. I would say truly random. 0:03:21.360 --> 0:03:24.880 With randomness comes chaos. You never know what I what 0:03:24.960 --> 0:03:28.000 will happen, but there's there's always a probability and a 0:03:28.080 --> 0:03:31.040 chance of things, of certain things happening. I'd like to 0:03:31.040 --> 0:03:35.360 say random. I'm religious, so I feel like everything happens 0:03:35.360 --> 0:03:38.520 for a reason. And yes it is random, but there's 0:03:38.520 --> 0:03:41.920 a purpose behind everything. I think it's a mixture of both, 0:03:42.760 --> 0:03:46.680 like like it's random, but it can appear chaotic because 0:03:46.720 --> 0:03:51.200 of how everything is truly chaotic, because like on a 0:03:51.320 --> 0:03:55.800 smaller level, everything is like moving really fast, but at 0:03:55.880 --> 0:04:00.560 like a bigger level, we we don't see any of that. Wow, 0:04:00.600 --> 0:04:02.720 So what do you think of those answers for I 0:04:02.760 --> 0:04:05.080 think they were all over the place. They were actually, 0:04:05.160 --> 0:04:08.400 um kind of random. They were random and chaotic. I 0:04:08.440 --> 0:04:11.080 feel like I feel like people had no idea what 0:04:11.160 --> 0:04:14.400 I was asking them. You know, I feel like people 0:04:14.440 --> 0:04:15.840 just I feel like they had no idea what they 0:04:15.840 --> 0:04:19.040 were answering. You know, some of those people I remember 0:04:19.760 --> 0:04:21.920 recording these interviews, and some of those people, as the 0:04:21.960 --> 0:04:23.480 words were coming out of their mouth, I felt like 0:04:23.520 --> 0:04:25.680 they surprised them as much as they did me. Like 0:04:25.800 --> 0:04:28.240 it was all over the place. Yeah, well, I feel 0:04:28.240 --> 0:04:30.479 like some people it's interesting. Some people related to the 0:04:30.560 --> 0:04:33.200 question that question to the other question, which is like 0:04:33.279 --> 0:04:36.320 does the universe have a purpose, Like do things happen 0:04:36.440 --> 0:04:39.039 for a reason or do they is it just like 0:04:39.080 --> 0:04:42.120 a random role to die and nobody is really in charge? 0:04:42.360 --> 0:04:44.880 Like that's the question, right, like, is somebody in charge 0:04:44.880 --> 0:04:47.919 of the universe or is it impossible for anyone to 0:04:48.040 --> 0:04:49.839 kind of predict what it's going to do. Yeah, I 0:04:49.839 --> 0:04:51.359 think you're right. That does get at the heart of 0:04:51.360 --> 0:04:53.159 the question. You know, what's going to happen in the 0:04:53.240 --> 0:04:56.760 universe and can we tell and can we influence it? Right? 0:04:57.200 --> 0:04:59.520 Is the universe sort of churning on without our ability 0:04:59.520 --> 0:05:02.520 to change direction at all in some sort of way 0:05:02.520 --> 0:05:05.360 that's been determined since the dawn of time? Or can 0:05:05.400 --> 0:05:06.960 we nudge it and push it in one way or 0:05:06.960 --> 0:05:08.720 the other? You know, make the calves a win? Or 0:05:08.880 --> 0:05:10.560 can you if you jump up and down in front 0:05:10.560 --> 0:05:13.640 of your television enough where the Warriors win another NBA championship? 0:05:13.640 --> 0:05:15.920 You know, can you influence the world? I think that's 0:05:15.960 --> 0:05:18.279 a that's an interesting and deep question. Yeah, that's probably 0:05:18.320 --> 0:05:20.919 the one people were actually having in their mind. Yeah, 0:05:21.120 --> 0:05:23.800 so maybe let's go back in history, and I like 0:05:23.880 --> 0:05:27.000 how you think about this question a lot, Daniel, which 0:05:27.040 --> 0:05:28.960 is that you sort of start with early man like 0:05:29.080 --> 0:05:33.839 the cavemen and women and women early humans. Um, we're 0:05:33.880 --> 0:05:35.520 really just kind of at the mercy of all the 0:05:35.560 --> 0:05:38.360 elements and all the animals out there, and the weather 0:05:38.560 --> 0:05:41.120 and so they to them, the universe was this crazy, 0:05:41.240 --> 0:05:44.400 random and chaotic place, right, Yeah, And it actually touches 0:05:44.480 --> 0:05:47.720 on sort of my personal theory of consciousness, which is 0:05:47.760 --> 0:05:51.600 that we developed this awareness because we are looking out 0:05:51.640 --> 0:05:54.880 into the world for other people or other ideas, are 0:05:54.920 --> 0:05:58.600 their intelligences, and we have this hyperactive ability to see agency, 0:05:58.640 --> 0:06:01.000 to see intention in something that we don't understand, and 0:06:01.000 --> 0:06:03.760 we imagine that there must be a mind behind it. 0:06:04.120 --> 0:06:05.880 And so I think for a long time people's view 0:06:05.960 --> 0:06:09.400 the world was that it was controlled by other greater minds. 0:06:09.480 --> 0:06:12.039 You know, what controls the lightning? Why do some people 0:06:12.080 --> 0:06:14.760 die of disease? All this stuff? And then as there 0:06:14.839 --> 0:06:18.360 must be like a consciousness that is shooting out these 0:06:18.440 --> 0:06:22.080 lightning bolts or making it rain, or you know, making 0:06:22.080 --> 0:06:24.159 the sun come out, or killing my baby of some 0:06:24.200 --> 0:06:27.240 horrible disease, right, like, there must be. It's hard to 0:06:27.240 --> 0:06:29.320 live in this world if you don't have the sense 0:06:29.360 --> 0:06:32.680 that there's somebody else in charge. Right There's a lot 0:06:32.720 --> 0:06:34.440 of suffering and a lot of pain, and a lot 0:06:34.440 --> 0:06:37.960 of unexplained events, and it's nice to think somebody else 0:06:38.120 --> 0:06:40.160 out there is taking care of it, or somebody's in 0:06:40.240 --> 0:06:42.400 charge of it. But there's a reason, right yeah, that 0:06:42.440 --> 0:06:46.920 there's a reason, that there's some design, it's not just random. Um. 0:06:46.960 --> 0:06:49.799 But then as history progresses that we were saying earlier, 0:06:49.800 --> 0:06:51.800 you know, sigence comes along and says, well, there are 0:06:51.839 --> 0:06:54.280 seemed to be some rules, not just like that anything 0:06:54.320 --> 0:06:57.159 can happen. You can't have an ostrich here and then 0:06:57.160 --> 0:06:58.839 all of a sudden the ostrich is gone. There are 0:06:58.920 --> 0:07:01.240 some rules that limit what can happen. If you know 0:07:01.279 --> 0:07:04.359 what's happening now, there's a certain set of possibilities for 0:07:04.400 --> 0:07:06.440 what can happen in one second, in two seconds. And 0:07:06.560 --> 0:07:09.400 you know that's physics, right Well, it's it's started with 0:07:09.440 --> 0:07:12.920 like noticing patterns, right Like lightning doesn't just come out 0:07:12.920 --> 0:07:16.239 of nowhere, it comes out when there's these dark clouds 0:07:16.240 --> 0:07:19.880 in the sky, right yeah, absolutely absolutely, And people started 0:07:19.920 --> 0:07:23.400 noticing patterns and started putting those together and then asking themselves, 0:07:23.400 --> 0:07:26.040 can I use what I've learned in the past to 0:07:26.240 --> 0:07:29.440 predict the future? Right Like, if I have the same 0:07:29.560 --> 0:07:32.080 set of events that happened yesterday, am I gonna be 0:07:32.080 --> 0:07:33.800 able to tell what's going to happen next week? If 0:07:33.840 --> 0:07:36.360 the same thing happens, If I roll a ball down 0:07:36.400 --> 0:07:38.800 the hill yesterday and it goes up to a certain speed, 0:07:38.920 --> 0:07:41.920 Will the same thing happened tomorrow? Right? Right? Or if 0:07:41.920 --> 0:07:43.840 I throw a ball in the air and I know 0:07:43.920 --> 0:07:46.000 which direction it's going and how fast it is going, 0:07:46.040 --> 0:07:48.600 can I predict where it's gonna land exactly? If I 0:07:48.600 --> 0:07:51.760 build a catapult, can I basically aim it right exactly? 0:07:51.760 --> 0:07:55.160 And that's how military technology drove science even hundreds of 0:07:55.280 --> 0:07:58.360 years ago. Right, Where do I shoot my cannon exactly 0:07:58.360 --> 0:08:01.240 to get over that wall? Well, that's kind of where 0:08:01.360 --> 0:08:03.920 um Newton came in, right, Isaac Newton, And that's why 0:08:03.960 --> 0:08:07.000 they say he kind of gave birth to science, right, 0:08:07.120 --> 0:08:09.800 or at least the scientific Revolution. No, I think it 0:08:09.840 --> 0:08:12.520 was earlier than that. Newton came along well after folks 0:08:12.600 --> 0:08:17.160 like Galileo and and Francis Bacon and those guys. They 0:08:17.280 --> 0:08:20.280 really were the first ones to do experiments and to say, 0:08:20.680 --> 0:08:22.600 let's see what the rules the universe is following, and 0:08:22.680 --> 0:08:24.360 let's see if we can try to deduce them and 0:08:24.480 --> 0:08:27.280 use those to predict the outcome of future experiments. They're 0:08:27.320 --> 0:08:29.480 really were the first ones to connect the idea of 0:08:29.520 --> 0:08:32.640 a scientific universe to the actual experiments they do to 0:08:32.920 --> 0:08:36.400 influence those ideas and to predict future results. And I 0:08:36.440 --> 0:08:38.640 think that's the key is that here we've developed a 0:08:38.679 --> 0:08:42.040 system science which cannot only explain what we've seen before, 0:08:42.120 --> 0:08:45.200 but can predict the future. And you are about to 0:08:45.240 --> 0:08:47.600 fire a cannonball at your enemy, you want to know 0:08:47.720 --> 0:08:50.160 where is that ball going to fly? And it's incredible 0:08:50.480 --> 0:08:53.200 that physics can do that. It can literally predict the 0:08:53.200 --> 0:08:56.720 future if you know enough about the situation right right, 0:08:56.880 --> 0:08:58.800 It's kind of like Google Maps. Now I can totally 0:08:58.800 --> 0:09:00.280 tell if you're going to be late to the meeting 0:09:00.360 --> 0:09:04.199 or not, or to a podcast recording they're gonna They're like, like, 0:09:04.880 --> 0:09:06.480 how long will they need to get home? They're like, 0:09:06.720 --> 0:09:08.920 they're gonna be late. It's not always a hard problem though. Joe. 0:09:09.040 --> 0:09:12.120 For example, it says if person equals Jorge, then late 0:09:12.200 --> 0:09:19.440 equals true every time, every time. A lot of data, 0:09:19.520 --> 0:09:24.800 and some of these things are simple, but some of 0:09:24.800 --> 0:09:27.679 these things are complicated, and it's incredible to witness as 0:09:27.679 --> 0:09:31.600 physics sort of builds confidence and science develops our ability 0:09:31.640 --> 0:09:35.360 to predict you know, chemical reactions and biological functioning, all 0:09:35.360 --> 0:09:38.679 sorts of things, and then it gives this creeping sense 0:09:38.720 --> 0:09:41.520 of is there anything that can escape science, Right, Can 0:09:41.520 --> 0:09:45.840 science predict everything? Like, if you knew enough about the world, 0:09:45.960 --> 0:09:48.040 could you break it all down to cannonballs to predict 0:09:48.080 --> 0:09:50.000 where all those cannonballs are going to fly and then 0:09:50.040 --> 0:09:52.720 tell exactly what's going to happen. Yeah, And it's it's 0:09:52.760 --> 0:09:54.880 like kind of like if you know that force equals 0:09:54.920 --> 0:10:00.080 mass science acceleration, like Needton figured out, um, then you 0:10:00.120 --> 0:10:03.600 can predict things like cannonballs and catapults and and and 0:10:03.679 --> 0:10:06.440 you could possibly predict like how a room full of 0:10:06.480 --> 0:10:09.599 particles move, right, Yeah, possibly you can extend that to 0:10:10.160 --> 0:10:15.120 can you predict how, um the whole world works? Yeah, 0:10:15.240 --> 0:10:16.720 what it's going to do and what people are going 0:10:16.760 --> 0:10:19.480 to do? Extrapolate to the whole universe, right, I mean, 0:10:19.520 --> 0:10:22.600 and that's the principle of determinism. It says, Look, if 0:10:22.640 --> 0:10:26.160 things follow rules, and the future is dependent only two things, 0:10:26.360 --> 0:10:29.720 one the rules and two the things that are happening 0:10:29.760 --> 0:10:32.400 now the current state. Right, given that if you know 0:10:32.520 --> 0:10:35.120 exactly where things are, imagine the whole universe is just 0:10:35.200 --> 0:10:37.400 a bunch of tiny cannonballs, and you know the rules 0:10:37.400 --> 0:10:39.720 of those cannonballs, and you know the position and direction 0:10:39.760 --> 0:10:43.000 of motion of all those cannonballs. Then in principle, given 0:10:43.040 --> 0:10:46.360 a super powerful universe sized computer, you should be able 0:10:46.400 --> 0:10:49.600 to predict the future one to five ten seconds into 0:10:49.600 --> 0:10:52.360 the future, a thousand seconds into the future, like every 0:10:52.360 --> 0:10:55.840 single molecule, atoms of atomic particle. You should be able 0:10:55.840 --> 0:10:58.480 if it follows rules, you should be able to kind 0:10:58.480 --> 0:11:00.680 of track where it's going to go if you tell 0:11:00.720 --> 0:11:04.120 you based on where things are now, what's going to happen? Exactly. 0:11:04.160 --> 0:11:06.200 It's kind of like this idea of a clock, right, 0:11:06.760 --> 0:11:09.920 is the universe giant clock just kind of clicking along 0:11:10.320 --> 0:11:13.080 or is there some kind of magic inside of it 0:11:13.120 --> 0:11:17.000 that makes it unpredictable? Right exactly? And the idea of 0:11:17.040 --> 0:11:20.000 the universe just being a huge clock, is both exciting 0:11:20.200 --> 0:11:23.319 and terrifying. Right. It's exciting because like, wow, can you 0:11:23.360 --> 0:11:25.640 imagine we could understand the universe that well, that we 0:11:25.640 --> 0:11:28.240 could predict the future, think about what we could do, right, 0:11:28.640 --> 0:11:31.520 But it's terrifying because it's sort of like you're trapped 0:11:31.520 --> 0:11:34.120 in this science cage where you have no influence over 0:11:34.120 --> 0:11:36.559 the world and everything you do and know and say, 0:11:36.559 --> 0:11:38.120 and that joke you're going to make in that fart 0:11:38.120 --> 0:11:41.560 you're gonna let slip are all predictable? Right, all those 0:11:41.559 --> 0:11:44.080 things are predictable. That's scary. It makes you feel like 0:11:44.440 --> 0:11:46.320 you are part of that watch and you're just clicking 0:11:46.320 --> 0:11:49.320 along because of the the you're reacting to things around 0:11:49.320 --> 0:11:52.360 you and your initial conditions, and so that's terrifying. And 0:11:52.400 --> 0:11:55.040 I think we have kind of in anate sense of 0:11:55.080 --> 0:11:58.920 like rejecting this idea that we're trapped, right we everyone 0:11:58.960 --> 0:12:01.560 wants to feel like they have free will, like everyone 0:12:01.600 --> 0:12:03.480 wants to know that they have a choice, right. Well, 0:12:03.520 --> 0:12:05.400 I guess so my kids don't feel that way, you know, 0:12:05.480 --> 0:12:08.560 like why did you hit your sister? Well she hit me, 0:12:08.800 --> 0:12:10.680 you know, like, well, so what you have no free will? 0:12:10.760 --> 0:12:13.719 Like you're completely determined by her behavior. Um. I have 0:12:13.840 --> 0:12:16.000 that argument with my kids so many times. I'm always 0:12:16.000 --> 0:12:20.800 thinking about the philosophical echoes of that. Um. Um, My 0:12:20.920 --> 0:12:23.160 kids are always rebelling. They're like, we want free will, 0:12:23.760 --> 0:12:26.080 don't tell us what to do, but they want you 0:12:26.120 --> 0:12:28.640 to follow rules. They're like, you promised daddy we could 0:12:28.679 --> 0:12:31.240 have ice cream, right, and so therefore you have to 0:12:31.400 --> 0:12:33.640 there's no more decision to be made. Kids are so 0:12:33.760 --> 0:12:38.720 unfair there, philosophically inconsistent. I think it's really the problem 0:12:38.720 --> 0:12:43.480 with kids Yeah, they're cute, but if they just read 0:12:43.520 --> 0:12:46.120 some more nice you know, and some some carl and 0:12:46.240 --> 0:12:49.199 some paper or whatever, they would be easier to be around. Yeah, 0:12:49.920 --> 0:12:53.680 forget those picture books. Let's introduce let's predict the universe. 0:13:07.080 --> 0:13:09.719 I think there's something fascinating about the deterministic view of 0:13:09.760 --> 0:13:13.000 the universe. But probably people out there thinking, Okay, maybe 0:13:13.000 --> 0:13:15.440 in theory you could predict the whole universe, but in 0:13:15.520 --> 0:13:18.439 practice that's impossible. I mean, you don't have a universe 0:13:18.480 --> 0:13:21.160 sized computer to break the whole universe, and even to 0:13:21.200 --> 0:13:24.679 predict like you know, a person is a huge number 0:13:24.720 --> 0:13:29.360 of articles, and so to do that calculation just seems impractical, right, right, 0:13:29.880 --> 0:13:32.440 It's practically impossible. But I think people reveled just to 0:13:32.520 --> 0:13:35.719 the idea of it, right, Like, are my thoughts my 0:13:35.840 --> 0:13:39.000 thoughts or just something that I'm programmed and that I 0:13:39.000 --> 0:13:42.040 will inevitably have and do. Yeah, and that's a really 0:13:42.120 --> 0:13:46.440 deep question. And so um, we started out with prehistoric 0:13:46.480 --> 0:13:48.839 man feeling like the universe is full of random of 0:13:48.960 --> 0:13:52.640 not random, but unexplained agency and intelligence all the way 0:13:52.679 --> 0:13:57.080 to like now, scientific physical determinism says, actually the universe 0:13:57.120 --> 0:13:59.680 just clicks along like a watch, right, and there's no 0:13:59.760 --> 0:14:02.199 free will. So let's take one step back from that, 0:14:02.360 --> 0:14:07.040 and that's chaos. That says, well, maybe the universe is deterministic, sure, 0:14:07.480 --> 0:14:10.280 but that doesn't mean it's necessarily practical for you to 0:14:10.320 --> 0:14:13.560 predict it because the way things play out is really 0:14:13.679 --> 0:14:17.680 sensitive to exactly how things started. Well, I think I 0:14:17.720 --> 0:14:20.480 think some people who responded to their question maybe weren't 0:14:20.480 --> 0:14:22.560 sure about the difference, right, Like, what's the difference between 0:14:22.600 --> 0:14:26.680 something being chaotic and something being random? Right? And so 0:14:26.920 --> 0:14:29.000 let's drill into that. So let's take, for an example, 0:14:29.360 --> 0:14:32.040 the roll of a dice. Right, people think of rolling 0:14:32.040 --> 0:14:35.880 dice is random, but actually it's chaotic, meaning that it's 0:14:35.880 --> 0:14:39.760 hard to predict, but it is deterministic. What do you 0:14:39.760 --> 0:14:42.400 mean if you knew exactly how I threw the dice, 0:14:42.480 --> 0:14:45.320 like exactly the direction and the spin and all the 0:14:45.360 --> 0:14:47.680 molecules of the air, then you could treat the molec 0:14:47.720 --> 0:14:51.160 little cannonballs, little particles, and you could model how it rolls, 0:14:51.240 --> 0:14:53.800 and you could, in theory, predict exactly how the dice 0:14:53.880 --> 0:14:56.640 rolled every time, meaning like if I if i'm if 0:14:56.640 --> 0:14:58.760 I'm seeing footage of you throwing to die, and like 0:14:58.760 --> 0:15:02.480 like I pause the video just as to die leave 0:15:02.520 --> 0:15:05.680 your hands, then I could you know know where they are, 0:15:06.120 --> 0:15:08.320 I know which direction are going, how fast are going. 0:15:08.440 --> 0:15:12.240 I could run some kind of computer simulation to like 0:15:12.600 --> 0:15:14.880 follow the die and predict what they're going to do 0:15:14.920 --> 0:15:17.840 when they bounce off the table on roll around, I 0:15:17.880 --> 0:15:20.760 could potentially predict what the die are going to show. 0:15:20.840 --> 0:15:23.520 That's right, because we're saying that the universe in that 0:15:23.560 --> 0:15:25.640 case is deterministic, and so you should be able to 0:15:25.680 --> 0:15:29.480 predict the future given enough information about the setup. Right now, 0:15:29.560 --> 0:15:32.720 that's a hard problem, and that's why we use dies, right, 0:15:32.760 --> 0:15:36.240 because it's really difficult, and nobody can practically like bring 0:15:36.280 --> 0:15:38.800 a mini computer into Las Vegas and use that to 0:15:38.840 --> 0:15:42.000 predict who's going to win it craps, right though, in theory, 0:15:42.280 --> 0:15:45.280 In theory, you could if the universe was deterministic but 0:15:45.520 --> 0:15:49.080 very sensitive to exactly how somebody's rolling the dice. Right 0:15:49.240 --> 0:15:51.240 when you throw the dice of craps, if you flip 0:15:51.320 --> 0:15:53.040 it this way or that way, then it's going to 0:15:53.080 --> 0:15:55.400 bounce slightly differently, and how it's going to hit that 0:15:55.680 --> 0:15:57.760 you know, the felt on the table. It's all very 0:15:57.880 --> 0:16:00.600 very sensitive and a very small change how you throw 0:16:00.600 --> 0:16:03.200 it can result in a totally different number. That's what 0:16:03.280 --> 0:16:06.800 we mean by chaos. It means that it's like that 0:16:06.840 --> 0:16:09.280 the butterfly effect, right, like the idea that if you 0:16:09.640 --> 0:16:12.240 butterfly flaps its wing here, it's going to have a 0:16:12.360 --> 0:16:15.080 huge effect, maybe potentially on the weather and on the 0:16:15.120 --> 0:16:17.280 other side of the world. Right, it's like a very 0:16:17.320 --> 0:16:20.360 sensitive system. That's right. The weather is a great example 0:16:20.800 --> 0:16:23.480 because we understand all the processes of weather. I mean, 0:16:23.480 --> 0:16:25.480 it's hot air, it's cold air, it's water. We know 0:16:25.560 --> 0:16:28.400 that stuff. It's pretty simple chemistry. But altogether, an entire 0:16:28.520 --> 0:16:32.280 planet is really difficult to describe because it's huge and 0:16:32.360 --> 0:16:35.000 it's really sensitive. Like, as you say, a butterfly flapping 0:16:35.040 --> 0:16:38.680 its wings in China could change the way this air flows, 0:16:38.720 --> 0:16:41.040 which could change the way that air flows, which bounces 0:16:41.040 --> 0:16:43.640 off this building, which turns into a rainstorm, which collides 0:16:43.680 --> 0:16:46.200 with this cloud and causes a hurricane. Right, it's not 0:16:46.280 --> 0:16:48.760 true that every time a butterfly flaps its wings you 0:16:48.760 --> 0:16:53.920 get a hurricane. But sometimes so. Weather is chaotic, but 0:16:54.000 --> 0:16:56.560 it's not random, is that what you're saying? That ran like, 0:16:56.640 --> 0:16:59.840 if we could keep track of every single butterfly in 0:16:59.880 --> 0:17:02.360 the world flapping its wing. We would be able to 0:17:02.400 --> 0:17:05.560 predict the weather if we had a giant supercomputer the 0:17:05.600 --> 0:17:08.720 size of the Solar System. But since we don't, then 0:17:09.240 --> 0:17:13.840 weather it seems random, but actually it's chaotic exactly, And 0:17:13.840 --> 0:17:15.960 that's exactly what scientists are trying to do. They're building 0:17:16.080 --> 0:17:19.240 bigger and bigger and faster computers to try to simulate 0:17:19.400 --> 0:17:21.880 more and more of the Earth's atmosphere to get better 0:17:21.880 --> 0:17:24.000 and better predictions of weather. In fact, I think like 0:17:24.119 --> 0:17:27.280 all the top ten supercomputers in the world are devoted 0:17:27.280 --> 0:17:30.160 to that problem, like modeling the weather, because it's important. 0:17:30.400 --> 0:17:33.720 But you're exactly right, it's actually chaotic, meaning it's deterministic 0:17:34.000 --> 0:17:36.800 but really sensitive to exactly how it started. But it 0:17:36.880 --> 0:17:40.440 seems random because it's it's too difficult for us to calculate. 0:17:40.480 --> 0:17:42.920 In principle, we should be able to, but we can't. 0:17:42.920 --> 0:17:46.199 Another example is flipping a coin. Right, based on how 0:17:46.240 --> 0:17:48.040 you flip the coin, you should be able to model 0:17:48.080 --> 0:17:49.960 how it spins through the air and how it bounces 0:17:49.960 --> 0:17:51.840 off air molecule and how it hits the ground and 0:17:51.840 --> 0:17:54.520 where it lands. But it's a difficult problem. So we 0:17:54.560 --> 0:17:57.040 can use it to model randomness to say it's kind 0:17:57.040 --> 0:18:00.640 of like randomness. Really it's just chaotic though. But then 0:18:00.680 --> 0:18:05.240 if I flip the coin a hundred times, most likely 0:18:05.560 --> 0:18:07.919 half of those times will be head and half of 0:18:07.920 --> 0:18:10.520 those times will be tails. Right, So where does that 0:18:10.720 --> 0:18:13.760 fit into chaos theory? Like why is it predictable on 0:18:13.800 --> 0:18:18.639 a statistical basis? Okay, so that's fascinating. That's an emergent phenomenon. Right. 0:18:18.680 --> 0:18:22.320 That says if you understand the tiny little local laws 0:18:22.320 --> 0:18:25.040 of physics, like the laws of how the particles inside 0:18:25.040 --> 0:18:27.240 the coin move, you should be able to predict some 0:18:27.359 --> 0:18:30.359 larger effect. And it's true, there is a simple or 0:18:30.560 --> 0:18:33.480 description of that larger effect, right, if you understand how 0:18:33.480 --> 0:18:36.879 these things work. Um, So physics works on these layers. Right. 0:18:36.920 --> 0:18:38.879 You can either understand it a very low layer and 0:18:38.920 --> 0:18:40.680 try to model it all the way up to a 0:18:40.760 --> 0:18:42.800 higher layer, or you can just try to get an 0:18:42.880 --> 0:18:45.600 understanding of at a higher layer, just the same way. 0:18:46.080 --> 0:18:48.600 You could say, well, I can understand the way cannonball 0:18:48.640 --> 0:18:51.399 flies by modeling all the particles inside of it, or 0:18:51.480 --> 0:18:53.560 you could just use F equals m A, which treats 0:18:53.560 --> 0:18:56.040 the whole cannonball like one particle. If that's just a 0:18:56.160 --> 0:18:59.840 question of at what layer you're modeling something, right, Okay, 0:19:00.200 --> 0:19:04.119 so a coin is chaotic but not actually random, but 0:19:04.160 --> 0:19:07.360 not actually random. Yet, if the universe is deterministic, then 0:19:07.359 --> 0:19:10.920 a coin is chaotic but not actually random. Yeah, okay, 0:19:11.240 --> 0:19:13.400 got it, got it. But then it's the question of 0:19:13.640 --> 0:19:16.040 that's the really the nugget of the question is is 0:19:16.119 --> 0:19:19.679 the universe deterministic? Um, you know, if you have a 0:19:19.760 --> 0:19:22.720 particle or a billiard ball or cannonball or whatever, and 0:19:22.760 --> 0:19:25.639 you understand direction it's going, can you predict its future 0:19:25.840 --> 0:19:29.359 out into infinity? Right? Right? You tell exactly what's going 0:19:29.359 --> 0:19:32.000 to happen. But there's so many factors leading up to 0:19:32.040 --> 0:19:35.640 me tossing the coin that it's so unpredictable that it's 0:19:35.720 --> 0:19:38.240 it's it feels random, that's right. And so we have 0:19:38.320 --> 0:19:41.600 to separate between what's practical and what's in theory possible. 0:19:42.080 --> 0:19:45.120 Anything that's chaotic. We're saying, in theory, if you knew enough, 0:19:45.359 --> 0:19:49.080 you could predict it, right, whereas but in practice that 0:19:49.240 --> 0:19:53.280 we can't. So it's it's it's can't. So it seems random. 0:19:53.520 --> 0:19:56.639 Random number generators and computers when they try to come 0:19:56.720 --> 0:19:58.840 up with a random number, it's not really random. You're 0:19:58.840 --> 0:20:02.440 saying it's just an algorithm. That's very that's chaotic. That's right. 0:20:02.440 --> 0:20:05.840 Computers by construction are deterministic, right, We've built them to 0:20:05.920 --> 0:20:08.879 be deterministic. Every time you run a program, it should 0:20:08.880 --> 0:20:10.399 give you the same answer if you give it the 0:20:10.440 --> 0:20:13.520 same input. Right. That's there's no way for computer to 0:20:13.560 --> 0:20:16.800 do anything but that. It's like a series of logic gates. 0:20:16.840 --> 0:20:19.280 And you know, how it's implemented is not important, but 0:20:19.640 --> 0:20:22.840 you know it's a system for doing deterministic calculations. That's 0:20:22.880 --> 0:20:25.439 what a computer is. So it's impossible for computer to 0:20:25.520 --> 0:20:28.600 be truly random. All the random number generators in your 0:20:28.600 --> 0:20:32.680 favorite Python code are actually pseudo random number generators. They're 0:20:32.680 --> 0:20:36.280 just chaotic. They take a seed a number to start from, 0:20:36.359 --> 0:20:38.199 and then they spin off of that and generate a 0:20:38.200 --> 0:20:40.040 sequence of numbers. But if you give them the same 0:20:40.080 --> 0:20:44.120 seed twice, they'll generate the same sequence of numbers twice. Wow. 0:20:44.359 --> 0:20:46.119 So like if you're playing a video game and you're 0:20:46.160 --> 0:20:49.560 inside of a virtual world, that world is totally determinating. 0:20:50.240 --> 0:20:53.320