1 00:00:08,560 --> 00:00:11,360 Speaker 1: Hey, am I speaking to the real Joorge today? 2 00:00:11,440 --> 00:00:12,280 Speaker 2: Who else could it be? 3 00:00:12,480 --> 00:00:14,800 Speaker 1: I don't know. It could be the simulated Jorge or 4 00:00:14,840 --> 00:00:18,120 Speaker 1: an AI generated horheage GPT. 5 00:00:18,800 --> 00:00:21,960 Speaker 2: Yes, chat Jorge. Would it make a difference. 6 00:00:22,040 --> 00:00:24,360 Speaker 1: That sounds like something the simulated Jorge would say? 7 00:00:24,520 --> 00:00:27,360 Speaker 2: Mmm. I kind of wish I had simulated Horges. Then 8 00:00:27,600 --> 00:00:30,280 Speaker 2: I might avoid a lot of mistakes I make. Or 9 00:00:30,280 --> 00:00:31,960 Speaker 2: they could do all the work while I sleep in. 10 00:00:32,040 --> 00:00:34,239 Speaker 1: Why do you think simulated Hojoges are less likely to 11 00:00:34,240 --> 00:00:34,879 Speaker 1: make mistakes? 12 00:00:35,000 --> 00:00:36,879 Speaker 2: No? I mean they would do the mistakes, and then 13 00:00:36,920 --> 00:00:39,080 Speaker 2: I would learn from them. That's the idea. 14 00:00:39,159 --> 00:00:39,319 Speaker 3: Right. 15 00:00:39,520 --> 00:00:41,000 Speaker 1: That does sound useful, But I think you have to 16 00:00:41,080 --> 00:00:44,000 Speaker 1: be careful about the sim Jorges organizing and rising up 17 00:00:44,000 --> 00:00:44,479 Speaker 1: against you. 18 00:00:44,680 --> 00:00:45,840 Speaker 3: Oh do you think. 19 00:00:45,680 --> 00:00:48,560 Speaker 2: They would form their own union or a revolt? 20 00:00:48,560 --> 00:00:51,800 Speaker 1: Do you mean, yeah, either mutiny or fair wages. Either one. 21 00:00:52,040 --> 00:00:53,720 Speaker 2: Well, I could just pay them in simulated money. 22 00:00:53,760 --> 00:00:55,440 Speaker 1: I guess as long as they can use that to 23 00:00:55,440 --> 00:00:57,920 Speaker 1: feed their simulated children, I bet they'd be happy. Oh. 24 00:00:57,960 --> 00:01:01,680 Speaker 2: No, I definitely provide simulated benefits too. The whole simulated 25 00:01:01,680 --> 00:01:02,920 Speaker 2: family gets a bonus. 26 00:01:03,000 --> 00:01:17,600 Speaker 1: You're not a good employer, but you can simulate one. 27 00:01:20,640 --> 00:01:23,480 Speaker 2: Hi, I'm Jory mccartoonists and the author of Oliver's Great 28 00:01:23,480 --> 00:01:24,560 Speaker 2: Big Universe. Hi. 29 00:01:24,680 --> 00:01:25,240 Speaker 3: I'm Daniel. 30 00:01:25,319 --> 00:01:28,520 Speaker 1: I'm a particle physicist and a professor at UC Irvine, 31 00:01:28,640 --> 00:01:32,200 Speaker 1: and I am constantly simulating crazy conditions. 32 00:01:32,400 --> 00:01:34,440 Speaker 2: You mean in your life or in your work. 33 00:01:35,160 --> 00:01:37,160 Speaker 1: Well, work is a big part of my life. But yeah, 34 00:01:37,200 --> 00:01:41,720 Speaker 1: my job involves simulating collisions at very high energies all 35 00:01:41,760 --> 00:01:42,160 Speaker 1: the time. 36 00:01:42,840 --> 00:01:45,240 Speaker 2: And you also actually do them, right, You actually collide 37 00:01:45,240 --> 00:01:46,800 Speaker 2: things at the Large Hadron Collider. 38 00:01:46,959 --> 00:01:49,880 Speaker 1: That's right. We both collide particles together in real life, 39 00:01:50,040 --> 00:01:53,200 Speaker 1: and we simulate what would happen if we collided particles 40 00:01:53,280 --> 00:01:56,919 Speaker 1: under various different potential laws of the universe to see 41 00:01:56,920 --> 00:01:59,840 Speaker 1: what might happen. Will the Earth get gobbled up with 42 00:02:00,120 --> 00:02:02,400 Speaker 1: to create a black hole that destroys the Earth or not? 43 00:02:02,840 --> 00:02:03,600 Speaker 1: Let's find out. 44 00:02:03,800 --> 00:02:07,000 Speaker 2: Does that mean your whole career is a simulation or 45 00:02:07,040 --> 00:02:07,840 Speaker 2: your whole life? 46 00:02:08,040 --> 00:02:10,519 Speaker 1: You know, our computers are not fast enough to keep 47 00:02:10,600 --> 00:02:13,519 Speaker 1: up with reality. So while we generate lots and lots 48 00:02:13,560 --> 00:02:17,240 Speaker 1: of simulated collisions, the real collider has generated more collisions 49 00:02:17,280 --> 00:02:18,600 Speaker 1: than we could ever simulate. 50 00:02:19,360 --> 00:02:21,120 Speaker 2: But how do you know, Daniel, that we're not in 51 00:02:21,200 --> 00:02:24,160 Speaker 2: a simulation right now, Like you might think you're doing experiments, 52 00:02:24,200 --> 00:02:26,720 Speaker 2: but really you're just inside of a video game somewhere. 53 00:02:26,800 --> 00:02:28,440 Speaker 1: Well, I want to find the cheap goods, then, well I. 54 00:02:28,440 --> 00:02:29,919 Speaker 2: Think if you had found them by now, you probably 55 00:02:30,040 --> 00:02:31,280 Speaker 2: would have a noble price. 56 00:02:31,400 --> 00:02:34,880 Speaker 1: Right, I'm hoping smashing particles together gives me the cheek goods. 57 00:02:34,720 --> 00:02:37,080 Speaker 2: And then that opens up the real boss level. 58 00:02:38,120 --> 00:02:40,079 Speaker 1: Where I fight the simulated army of Jorges. 59 00:02:40,200 --> 00:02:44,519 Speaker 2: No, you fight the real Jegeo. That's the real boss. 60 00:02:45,240 --> 00:02:47,760 Speaker 2: But anyways, welcome to our podcast Daniel and Jorge Explain 61 00:02:47,840 --> 00:02:50,600 Speaker 2: the Universe, a production of iHeartRadio. 62 00:02:50,040 --> 00:02:52,359 Speaker 1: In which we use our tiny little minds to try 63 00:02:52,360 --> 00:02:55,639 Speaker 1: to understand the vast universe. We hope to build in 64 00:02:55,720 --> 00:02:59,800 Speaker 1: your head a simulation of sorts, one that describes the 65 00:02:59,800 --> 00:03:02,920 Speaker 1: way the real universe works out there. We hope to 66 00:03:03,160 --> 00:03:06,079 Speaker 1: encode into your brain some laws of physics that will 67 00:03:06,080 --> 00:03:09,120 Speaker 1: help you understand how the real universe out there is 68 00:03:09,320 --> 00:03:12,760 Speaker 1: smashing and bashing to create our Bonker's reality. 69 00:03:12,960 --> 00:03:15,399 Speaker 2: That's right, the universe are doing all kinds of amazing 70 00:03:15,520 --> 00:03:18,480 Speaker 2: and awe sometimes and saying things out there in reality. 71 00:03:18,800 --> 00:03:22,160 Speaker 2: And so it's our job as humans and as scientists 72 00:03:22,200 --> 00:03:25,000 Speaker 2: to understand what's going on and to ask questions, to 73 00:03:25,080 --> 00:03:27,519 Speaker 2: probe into the true answers to why things are the 74 00:03:27,520 --> 00:03:27,880 Speaker 2: way they are. 75 00:03:28,080 --> 00:03:30,520 Speaker 1: And the classical way that science does this is with 76 00:03:30,760 --> 00:03:35,160 Speaker 1: theories and experiments, hypotheses and tests. You have an idea, 77 00:03:35,240 --> 00:03:37,400 Speaker 1: you go and see out there in the universe. If 78 00:03:37,440 --> 00:03:40,200 Speaker 1: it works, you predict something happens, and you go and 79 00:03:40,280 --> 00:03:43,080 Speaker 1: check to see if it does. But the modern scientific 80 00:03:43,120 --> 00:03:45,839 Speaker 1: method has a third way, which lives sort of uncomfortably 81 00:03:45,880 --> 00:03:48,400 Speaker 1: between theory and experiments. 82 00:03:48,560 --> 00:03:51,240 Speaker 2: Oh, why is it uncomfortable? Is it like uncomfortable, awkward 83 00:03:51,320 --> 00:03:53,240 Speaker 2: or uncomfortable, like physically uncomfortable. 84 00:03:53,280 --> 00:03:55,080 Speaker 1: It's a little bit uncomfortable for those of us who 85 00:03:55,080 --> 00:03:57,320 Speaker 1: specialize in not to know where we fit into the 86 00:03:57,360 --> 00:04:01,360 Speaker 1: picture of science. Some people consider me experimental physicists. Some 87 00:04:01,400 --> 00:04:03,680 Speaker 1: people are like, nah, he mostly runs simulation, so he's 88 00:04:03,720 --> 00:04:06,040 Speaker 1: really a theorist. So you can be sort of like 89 00:04:06,120 --> 00:04:09,400 Speaker 1: uncomfortably between two different communities. If you do a lot 90 00:04:09,440 --> 00:04:10,960 Speaker 1: of simulations. 91 00:04:10,920 --> 00:04:13,640 Speaker 2: You start your own simulated community. Can you be like 92 00:04:13,680 --> 00:04:16,120 Speaker 2: a simulating physicist. 93 00:04:15,800 --> 00:04:20,120 Speaker 1: A simulator a simulate trist. That sounds not safe for work. 94 00:04:20,120 --> 00:04:24,680 Speaker 2: Actually, I don't know what you mean, but I'll take 95 00:04:24,680 --> 00:04:25,279 Speaker 2: your word for it. 96 00:04:25,400 --> 00:04:28,560 Speaker 1: You know, academic communities change pretty slowly, and for example, 97 00:04:28,720 --> 00:04:32,159 Speaker 1: in departments of physics, people tend to hire people that 98 00:04:32,200 --> 00:04:35,039 Speaker 1: are like them. The experimentalists get to hire somebody. They 99 00:04:35,080 --> 00:04:38,920 Speaker 1: want to hire somebody who's a blue blooded experimentalist down 100 00:04:38,960 --> 00:04:41,440 Speaker 1: to the core. So if you work at the intersection 101 00:04:41,600 --> 00:04:44,279 Speaker 1: of fields, you do some experiments, you do some theory, 102 00:04:44,320 --> 00:04:47,040 Speaker 1: maybe even do some computer science and machine learning, then 103 00:04:47,040 --> 00:04:48,760 Speaker 1: you don't necessarily have a home, you don't have a 104 00:04:48,839 --> 00:04:50,440 Speaker 1: tribe that's going to go to bat for you to 105 00:04:50,480 --> 00:04:52,839 Speaker 1: get hired. So it's sort of about the sociology of 106 00:04:52,880 --> 00:04:54,479 Speaker 1: science as a real practice. 107 00:04:54,920 --> 00:04:56,560 Speaker 2: Well, I think that kind of makes sense, right, Like 108 00:04:56,640 --> 00:05:00,239 Speaker 2: why hire a simulating physicist when you can just simulate one? 109 00:05:00,839 --> 00:05:02,000 Speaker 2: Why go to all the trouble? 110 00:05:02,120 --> 00:05:04,520 Speaker 1: You know, I think that's true. If we could simulate physicists, 111 00:05:04,560 --> 00:05:06,440 Speaker 1: we could get a lot more done. But we're not 112 00:05:06,560 --> 00:05:09,720 Speaker 1: quite there yet. Human physicists still have a little bit 113 00:05:09,720 --> 00:05:10,240 Speaker 1: of an edge. 114 00:05:10,440 --> 00:05:14,600 Speaker 2: Yeah, maybe till next week when chat GPT catches up 115 00:05:14,640 --> 00:05:15,960 Speaker 2: and starts doing physics. 116 00:05:16,200 --> 00:05:18,640 Speaker 1: I mean, have you ever asked chat GPT a physics question. 117 00:05:18,960 --> 00:05:21,120 Speaker 1: You don't get physics out, that's for sure. 118 00:05:21,240 --> 00:05:23,680 Speaker 2: But anyways, it is an interesting universe because I guess 119 00:05:23,720 --> 00:05:26,520 Speaker 2: sometimes there are questions. You can't just go out there 120 00:05:26,560 --> 00:05:28,840 Speaker 2: and try for yourself in the universe, right, that's right. 121 00:05:28,880 --> 00:05:31,719 Speaker 1: Simulation has emerged in the past fifty years as an 122 00:05:31,800 --> 00:05:34,839 Speaker 1: extraordinarily powerful tool as a little bit of experiment and 123 00:05:34,880 --> 00:05:37,160 Speaker 1: a little bit of theory, and it lets us answer 124 00:05:37,240 --> 00:05:40,680 Speaker 1: questions that we otherwise could not answer. It really is 125 00:05:40,720 --> 00:05:43,440 Speaker 1: a completely new tool in the science tool. 126 00:05:43,240 --> 00:05:45,680 Speaker 2: Belt, although I would argue it's maybe one of the 127 00:05:45,720 --> 00:05:48,599 Speaker 2: oldest tools in science. And so today on the podcast, 128 00:05:48,600 --> 00:05:57,800 Speaker 2: we'll be asking the question why do scientists do simulations? 129 00:05:58,080 --> 00:05:59,840 Speaker 2: Why do scientists do anything. 130 00:06:00,480 --> 00:06:03,119 Speaker 1: Other than the obvious that simulations are so much fun. 131 00:06:03,320 --> 00:06:05,600 Speaker 1: You get to build your own little universe. You are 132 00:06:05,640 --> 00:06:08,279 Speaker 1: the creator and god of that simulated universe. 133 00:06:08,520 --> 00:06:12,479 Speaker 2: Oh boy, is that that the ultimate goal? There? To 134 00:06:12,560 --> 00:06:17,200 Speaker 2: be gods? No, you know, you don't have to get 135 00:06:17,200 --> 00:06:19,440 Speaker 2: a degree for that. You could just buy some legos. 136 00:06:20,800 --> 00:06:22,760 Speaker 1: Oh, I've been doing that since I was a little kid. 137 00:06:22,800 --> 00:06:25,440 Speaker 1: I just want more and more powerful simulations. 138 00:06:26,000 --> 00:06:28,840 Speaker 2: You want more powerful legos, smaller legos. 139 00:06:28,960 --> 00:06:31,160 Speaker 1: Jokes aside, There is a real sense of power when 140 00:06:31,200 --> 00:06:34,440 Speaker 1: you create a simulated universe, because you are deciding what 141 00:06:34,520 --> 00:06:37,440 Speaker 1: the laws of physics are in that universe, what particles 142 00:06:37,440 --> 00:06:39,680 Speaker 1: do they have, how do they interact? And then you 143 00:06:39,720 --> 00:06:41,800 Speaker 1: get to see how it all plays out. 144 00:06:42,080 --> 00:06:44,440 Speaker 2: Mmmm yeah, I sort of get that. I mean I 145 00:06:44,480 --> 00:06:46,839 Speaker 2: write a lot, I create characters, and I sort of 146 00:06:46,839 --> 00:06:49,279 Speaker 2: build my own world. What's the difference. 147 00:06:49,440 --> 00:06:52,960 Speaker 1: Yeah, you could think of fiction as simulated human interaction 148 00:06:53,160 --> 00:06:55,839 Speaker 1: and lives. Right, we're exploring what it would be like 149 00:06:55,920 --> 00:06:58,120 Speaker 1: to be in those situations. 150 00:06:58,400 --> 00:07:00,080 Speaker 2: Yeah. Wait, did you just say your work. 151 00:06:59,920 --> 00:07:04,840 Speaker 1: Is simulations are definitely fiction. Sometimes they align with reality, 152 00:07:04,880 --> 00:07:07,400 Speaker 1: and one deep question is how well they align? What 153 00:07:07,520 --> 00:07:11,360 Speaker 1: lessons you can learn from your simulated fiction that carry 154 00:07:11,400 --> 00:07:13,160 Speaker 1: over into the real world. 155 00:07:13,560 --> 00:07:17,880 Speaker 2: Interesting, So your research is science fiction is what you're saying. 156 00:07:20,720 --> 00:07:23,160 Speaker 1: You know, I've always argued that there's a strong connection 157 00:07:23,240 --> 00:07:24,680 Speaker 1: between science and science fiction. 158 00:07:25,000 --> 00:07:25,240 Speaker 3: Right. 159 00:07:25,440 --> 00:07:27,640 Speaker 1: One aspect of science is like, well, what are the laws? 160 00:07:27,640 --> 00:07:28,080 Speaker 3: Could they be? 161 00:07:28,120 --> 00:07:28,240 Speaker 1: This? 162 00:07:28,400 --> 00:07:28,880 Speaker 3: Could they be? 163 00:07:28,960 --> 00:07:29,120 Speaker 2: That? 164 00:07:29,120 --> 00:07:33,400 Speaker 1: There's an element of creativity and exploration there, absolutely so. Yeah, 165 00:07:33,440 --> 00:07:36,880 Speaker 1: I'm constantly creating science fiction universes and trying to see 166 00:07:36,960 --> 00:07:38,400 Speaker 1: if they line up with ours. 167 00:07:39,240 --> 00:07:40,960 Speaker 2: And then you wonder why the other physicis don't want 168 00:07:40,960 --> 00:07:41,440 Speaker 2: to play with you. 169 00:07:43,520 --> 00:07:46,320 Speaker 1: Fortunately I got tenured before I revealed all of these 170 00:07:46,360 --> 00:07:48,120 Speaker 1: crazy instincts. That's the game. 171 00:07:50,120 --> 00:07:52,240 Speaker 2: Well, this is an interesting question, and so as usual, 172 00:07:52,320 --> 00:07:55,040 Speaker 2: we were wondering how many people out there had thought 173 00:07:55,080 --> 00:07:58,000 Speaker 2: about why scientists do the things they do, and in particular, 174 00:07:58,160 --> 00:08:00,560 Speaker 2: why they do simulations in their work. 175 00:08:00,840 --> 00:08:03,480 Speaker 1: So thanks very much to everybody who answers these questions 176 00:08:03,480 --> 00:08:06,400 Speaker 1: for this fun segment of the podcast, one of my favorites. 177 00:08:06,680 --> 00:08:09,280 Speaker 1: If you like to join the team or just answer 178 00:08:09,280 --> 00:08:12,120 Speaker 1: one or two questions right to us to questions at 179 00:08:12,240 --> 00:08:14,000 Speaker 1: Danielandhorge dot com. 180 00:08:14,200 --> 00:08:16,400 Speaker 2: So think about it for a second. If someone asks 181 00:08:16,400 --> 00:08:19,760 Speaker 2: you why scientists do simulations, what would you say. 182 00:08:19,800 --> 00:08:26,360 Speaker 4: Well, using simulations, we can observe scenarios in our models 183 00:08:26,880 --> 00:08:32,120 Speaker 4: that we can't necessarily observe in real life, and see 184 00:08:32,480 --> 00:08:36,079 Speaker 4: what can happen in certain situations like in a black 185 00:08:36,080 --> 00:08:38,520 Speaker 4: hole or when galaxies collide or something like that. 186 00:08:38,840 --> 00:08:44,319 Speaker 5: Scientists do simulations because the universe is really old, really big, 187 00:08:45,040 --> 00:08:49,160 Speaker 5: sometimes really destructive. Frankly, I'm happy they do a lot 188 00:08:49,200 --> 00:08:52,760 Speaker 5: of that modeling and simulations and don't necessarily try to 189 00:08:52,800 --> 00:08:57,520 Speaker 5: create big bang conditions on a big scale, or the 190 00:08:57,679 --> 00:08:59,240 Speaker 5: explosion of stars or something. 191 00:09:00,760 --> 00:09:03,439 Speaker 2: Couple of interesting answers did anyone look at you funny 192 00:09:03,440 --> 00:09:04,480 Speaker 2: when you ask them the question. 193 00:09:05,720 --> 00:09:07,839 Speaker 1: I don't know. These were all on the internet, so 194 00:09:08,000 --> 00:09:11,239 Speaker 1: I couldn't capture their facial expressions. Did they send an emoji? 195 00:09:12,600 --> 00:09:15,800 Speaker 1: But I do sense some relief in there that, for example, 196 00:09:15,800 --> 00:09:18,560 Speaker 1: we are trying to simulate galaxy collisions rather than trying 197 00:09:18,559 --> 00:09:20,400 Speaker 1: to arrange galaxy collisions. 198 00:09:20,559 --> 00:09:22,360 Speaker 2: Well, if we could do that, that'd be pretty cool. 199 00:09:23,160 --> 00:09:25,560 Speaker 2: I mean, not for those galaxies, but just to have 200 00:09:25,640 --> 00:09:26,120 Speaker 2: that power. 201 00:09:26,320 --> 00:09:28,679 Speaker 1: Yeah, you'd have to have like sign offs from every 202 00:09:28,720 --> 00:09:32,520 Speaker 1: alien civilization in both galaxies before you could even begin. 203 00:09:32,760 --> 00:09:34,800 Speaker 2: I guess that would be the polite thing to do. Yes. 204 00:09:35,240 --> 00:09:36,960 Speaker 2: But anyways, as you were saying, this is a big 205 00:09:37,000 --> 00:09:40,680 Speaker 2: part of how science is done these days, and so Daniel, 206 00:09:40,679 --> 00:09:42,960 Speaker 2: I guess let's start from the basics. What is a 207 00:09:43,000 --> 00:09:45,960 Speaker 2: simulation in your view as a physicists. 208 00:09:45,480 --> 00:09:48,840 Speaker 1: So, a simulation, or more specifically, a computer simulation, is 209 00:09:48,880 --> 00:09:53,200 Speaker 1: a specific program that involves a scientific model. A model 210 00:09:53,320 --> 00:09:56,079 Speaker 1: is like our picture of how the world might work. 211 00:09:56,360 --> 00:10:00,280 Speaker 1: It's like a simplified version of the real universe. Let's 212 00:10:00,320 --> 00:10:04,160 Speaker 1: us explore a specific question, and a simulation is usually 213 00:10:04,240 --> 00:10:07,240 Speaker 1: a program on a computer that uses like step by 214 00:10:07,240 --> 00:10:10,960 Speaker 1: step methods to explore the behavior of that model. 215 00:10:11,800 --> 00:10:15,440 Speaker 2: And usually this model has the form of an equation, right, Like, 216 00:10:15,480 --> 00:10:18,400 Speaker 2: for example, F equalsma is a model of the world, right, 217 00:10:18,440 --> 00:10:19,839 Speaker 2: and how things move in the world. 218 00:10:20,000 --> 00:10:22,560 Speaker 1: Yeah, the science we do is mathematical, and the way 219 00:10:22,559 --> 00:10:26,599 Speaker 1: we describe things is mathematical, and so usually that involves equations, 220 00:10:26,880 --> 00:10:29,640 Speaker 1: equations that represent constraints on the model, like the way 221 00:10:29,720 --> 00:10:32,120 Speaker 1: things have to happen. And as you say, F equals 222 00:10:32,200 --> 00:10:34,000 Speaker 1: ma is a model. If I want to toss a 223 00:10:34,040 --> 00:10:36,640 Speaker 1: baseball across my backyard, I want to answer the question 224 00:10:37,040 --> 00:10:39,560 Speaker 1: where is it going to land? Then I have lots 225 00:10:39,559 --> 00:10:42,320 Speaker 1: of possible ways to answer that question, but the most 226 00:10:42,320 --> 00:10:46,720 Speaker 1: appropriate ways to make the simplest model possible that still 227 00:10:46,760 --> 00:10:50,640 Speaker 1: captures everything that I'm interested in, and so often in 228 00:10:50,679 --> 00:10:53,240 Speaker 1: our world, like when we're tossing baseballs, we can do 229 00:10:53,280 --> 00:10:56,680 Speaker 1: something pretty simple just F equals ma, which ignores all 230 00:10:56,720 --> 00:11:00,160 Speaker 1: sorts of swarming quantum details about what's happening inside at 231 00:11:00,160 --> 00:11:03,959 Speaker 1: the baseball and just describes simple motion of a parabole. 232 00:11:04,400 --> 00:11:07,000 Speaker 2: Yeah, it's almost like you. I mean, as a scientist, 233 00:11:07,000 --> 00:11:09,120 Speaker 2: you're trying to come up with the rules of the universe, right, 234 00:11:09,120 --> 00:11:11,640 Speaker 2: that's sort of the goal of science, right, And what 235 00:11:11,880 --> 00:11:15,520 Speaker 2: sometimes that rule looks like is in a question that says, 236 00:11:15,559 --> 00:11:17,880 Speaker 2: you know, if you have a mass and you apply 237 00:11:17,920 --> 00:11:19,679 Speaker 2: a force to it, then it's going to start moving 238 00:11:19,679 --> 00:11:20,839 Speaker 2: with a certain acceleration. 239 00:11:21,000 --> 00:11:23,880 Speaker 1: Exactly in your words, these are all science fictions. We're 240 00:11:23,880 --> 00:11:26,120 Speaker 1: living in this world and we're wondering what are the rules, 241 00:11:26,200 --> 00:11:28,040 Speaker 1: and so we're trying a bunch of different rules, saying 242 00:11:28,080 --> 00:11:30,560 Speaker 1: does this rule describe our universe? Does that rule describe 243 00:11:30,600 --> 00:11:34,000 Speaker 1: our universe? So every sort of theoretical exploration of the 244 00:11:34,080 --> 00:11:37,400 Speaker 1: universe involves building a model and then asking the question 245 00:11:37,760 --> 00:11:40,960 Speaker 1: does that model align with the reality that we see. 246 00:11:41,120 --> 00:11:43,920 Speaker 1: Computer simulations are a special kind of model or a 247 00:11:43,920 --> 00:11:47,120 Speaker 1: special what a test? Really complicated models that we can't 248 00:11:47,160 --> 00:11:50,560 Speaker 1: otherwise test, Like the model F equals M a pretty simple. 249 00:11:50,600 --> 00:11:53,120 Speaker 1: I can use pencil and paper to make predictions, and 250 00:11:53,160 --> 00:11:54,960 Speaker 1: then I can throw a ball in my backyard to 251 00:11:55,000 --> 00:11:56,720 Speaker 1: confirm those predictions. 252 00:11:56,440 --> 00:11:58,720 Speaker 2: Right, because I guess F equals A has like a 253 00:11:58,800 --> 00:12:01,480 Speaker 2: mathematical But I think the idea is that you take 254 00:12:01,520 --> 00:12:03,240 Speaker 2: in a question like F equals in May and you 255 00:12:03,440 --> 00:12:06,000 Speaker 2: basically program that into a computer and say, you know, 256 00:12:06,280 --> 00:12:09,640 Speaker 2: any masses in this program, they have to move according 257 00:12:09,679 --> 00:12:10,440 Speaker 2: to this law. 258 00:12:10,679 --> 00:12:12,960 Speaker 1: That's right. If, for example, I don't just want to 259 00:12:13,000 --> 00:12:15,400 Speaker 1: describe one ball, but I want to describe like ten 260 00:12:15,440 --> 00:12:19,400 Speaker 1: to the twenty five balls, right, some huge number of balls. 261 00:12:19,640 --> 00:12:22,559 Speaker 1: Maybe I'm modeling an ideal gas, or like a swimming 262 00:12:22,600 --> 00:12:25,120 Speaker 1: pool full of ping pong balls or something, and I 263 00:12:25,160 --> 00:12:27,000 Speaker 1: want to describe that. Then I can no longer use 264 00:12:27,040 --> 00:12:28,959 Speaker 1: pencil and paper. But you're in. I can take those 265 00:12:29,000 --> 00:12:31,240 Speaker 1: equations and put them into a computer and ask the 266 00:12:31,240 --> 00:12:34,120 Speaker 1: computer to force those balls to follow that equation, and 267 00:12:34,160 --> 00:12:36,720 Speaker 1: then I could see what happens. It's sort of like 268 00:12:36,800 --> 00:12:38,559 Speaker 1: a virtual experiment. 269 00:12:38,960 --> 00:12:41,559 Speaker 2: Yeah, it's like you're creating your own little universe. 270 00:12:41,200 --> 00:12:44,720 Speaker 1: Right exactly. And this becomes super essential when we don't 271 00:12:44,720 --> 00:12:48,080 Speaker 1: have like a single equation that describes everything, Like we 272 00:12:48,120 --> 00:12:51,280 Speaker 1: don't have a solution to what happens when you put 273 00:12:51,320 --> 00:12:53,800 Speaker 1: ten to the twenty five ping pong balls into a 274 00:12:53,800 --> 00:12:55,920 Speaker 1: swimming pool. We just don't know how to do that 275 00:12:56,000 --> 00:12:59,440 Speaker 1: calculation to come up with some nice summary of the results. 276 00:13:00,120 --> 00:13:01,840 Speaker 1: What we can do is put it into a computer 277 00:13:01,920 --> 00:13:04,959 Speaker 1: and have the computer step it forward in time very carefully, 278 00:13:05,120 --> 00:13:07,880 Speaker 1: and we can see what happens without ever actually having 279 00:13:07,880 --> 00:13:09,800 Speaker 1: to buy that number of ping bomb balls. 280 00:13:09,960 --> 00:13:12,720 Speaker 2: Right. That's sort of the power of the computer, right, 281 00:13:12,800 --> 00:13:16,440 Speaker 2: Like you can simulate one ball, which is a calculator, right, 282 00:13:16,520 --> 00:13:18,400 Speaker 2: Like you can say after one second, it's going to 283 00:13:18,400 --> 00:13:19,839 Speaker 2: be here, after two seconds, it is going to be 284 00:13:19,880 --> 00:13:22,880 Speaker 2: here by following these rules. But if you have, like 285 00:13:22,920 --> 00:13:26,120 Speaker 2: you said, a whole bunch of balls, or a more 286 00:13:26,160 --> 00:13:28,960 Speaker 2: complicated system, then a computer can sort of do all 287 00:13:29,000 --> 00:13:31,480 Speaker 2: those calculations for you faster, exactly. 288 00:13:31,600 --> 00:13:34,960 Speaker 1: One huge advantage is tackling a very large number of objects, 289 00:13:35,120 --> 00:13:38,040 Speaker 1: and the other is when we don't have the equations, 290 00:13:38,040 --> 00:13:40,480 Speaker 1: we don't know how to solve them, Like for f equals, 291 00:13:40,480 --> 00:13:42,720 Speaker 1: I may we know how to solve that. Technically, that 292 00:13:42,920 --> 00:13:46,880 Speaker 1: is a differential equation because A is a second derivative 293 00:13:46,920 --> 00:13:50,200 Speaker 1: of position, right, there's derivatives on both sides. And in 294 00:13:50,240 --> 00:13:53,400 Speaker 1: general and mathematics, differential equations are very very hard to solve. 295 00:13:53,400 --> 00:13:56,040 Speaker 1: This a small number that we actually know how to solve. 296 00:13:56,520 --> 00:13:58,880 Speaker 1: So sometimes you have a system that's described by a 297 00:13:58,880 --> 00:14:02,480 Speaker 1: differential equation you don't know how to solve, Like fluid flow, 298 00:14:02,520 --> 00:14:05,440 Speaker 1: for example, described by the Navier Stokes equation. We don't 299 00:14:05,440 --> 00:14:07,760 Speaker 1: know how to solve that. In general. But what we 300 00:14:07,800 --> 00:14:10,400 Speaker 1: can do on a computer is approximated. You can say, 301 00:14:10,520 --> 00:14:12,600 Speaker 1: you know, let's just move it forward in time, not 302 00:14:12,840 --> 00:14:15,640 Speaker 1: a year or a minute or some long period of time, 303 00:14:15,640 --> 00:14:18,760 Speaker 1: but just like a microsecond, and across a microsecond, we 304 00:14:18,760 --> 00:14:21,360 Speaker 1: can make some approximations. We can say, let's not use 305 00:14:21,360 --> 00:14:23,560 Speaker 1: the full equation, let's simplify it and take some like 306 00:14:23,720 --> 00:14:25,880 Speaker 1: linear approximation of it, and then if we take a 307 00:14:25,880 --> 00:14:28,320 Speaker 1: lot of tiny little steps, we hope that we roughly 308 00:14:28,320 --> 00:14:29,520 Speaker 1: get the right answer. 309 00:14:29,280 --> 00:14:31,240 Speaker 2: Right, because I think, as you were saying, like something 310 00:14:31,280 --> 00:14:34,240 Speaker 2: like f EQUOSM has the solution, meaning that you can 311 00:14:34,480 --> 00:14:37,200 Speaker 2: derive a formula for like the precision of your ball 312 00:14:37,240 --> 00:14:40,240 Speaker 2: at all times, where you can just like after three 313 00:14:40,280 --> 00:14:41,960 Speaker 2: seconds you just put the time in and it gives 314 00:14:42,000 --> 00:14:44,000 Speaker 2: you the position of the ball, right, because you can 315 00:14:44,080 --> 00:14:46,880 Speaker 2: integrate that equation and find the solution. But some equations 316 00:14:46,880 --> 00:14:49,480 Speaker 2: you can, like they're so complex you can get a 317 00:14:49,560 --> 00:14:51,400 Speaker 2: formally that will tell you what's going to happen ten 318 00:14:51,480 --> 00:14:53,360 Speaker 2: years from now or twenty years from now. Right, those 319 00:14:53,400 --> 00:14:56,040 Speaker 2: you need to do little steps by little steps exactly. 320 00:14:56,080 --> 00:14:58,240 Speaker 1: And the crucial idea there is that you're making a 321 00:14:58,280 --> 00:15:00,880 Speaker 1: linear approximation you're taking the full equation which you don't 322 00:15:00,880 --> 00:15:02,840 Speaker 1: know how to solve, and you're saying, well, let's replace 323 00:15:02,880 --> 00:15:05,480 Speaker 1: it with an approximate version of it, which is not 324 00:15:05,520 --> 00:15:07,520 Speaker 1: going to be correct, but it might be correct for 325 00:15:07,720 --> 00:15:11,040 Speaker 1: like a microsecond. And so we'll use the approximate linear 326 00:15:11,160 --> 00:15:12,840 Speaker 1: version of that that we do know how to solve 327 00:15:12,960 --> 00:15:15,120 Speaker 1: from a tiny little step, and then we'll start again, 328 00:15:15,160 --> 00:15:17,240 Speaker 1: and we'll make another tiny little step, and we hope 329 00:15:17,240 --> 00:15:19,760 Speaker 1: them little mistakes cancel out and don't build up into 330 00:15:19,800 --> 00:15:21,240 Speaker 1: some big overall mistake. 331 00:15:21,680 --> 00:15:24,400 Speaker 2: Right Yeah. It's almost like if you take small enough steps, 332 00:15:24,440 --> 00:15:28,000 Speaker 2: then you're less likely to deviate from the reality of. 333 00:15:27,960 --> 00:15:30,560 Speaker 1: It, right, Yeah, exactly. And people who do approximations know 334 00:15:30,640 --> 00:15:32,560 Speaker 1: that there's lots of times this is useful. Like you 335 00:15:32,560 --> 00:15:35,360 Speaker 1: want to calculate Trigg function like sign sign is really 336 00:15:35,400 --> 00:15:38,480 Speaker 1: hard to calculate like sort of from scratch, but for 337 00:15:38,640 --> 00:15:41,720 Speaker 1: very small values of the angle, sign of x is 338 00:15:41,760 --> 00:15:44,640 Speaker 1: just equal to x, you can like approximate this complicated 339 00:15:44,680 --> 00:15:47,280 Speaker 1: function with a simple one. It mostly gets the right answer. 340 00:15:47,440 --> 00:15:48,480 Speaker 1: That's just one example. 341 00:15:48,560 --> 00:15:51,320 Speaker 2: I'm not sure you're going to Trigonometry usually makes things 342 00:15:51,520 --> 00:15:55,360 Speaker 2: you understand, but I think I think we get the idea, 343 00:15:55,400 --> 00:15:57,120 Speaker 2: which is that you know, if you take small enough 344 00:15:57,160 --> 00:16:00,360 Speaker 2: steps and you you sort of a simplified version of 345 00:16:00,400 --> 00:16:04,560 Speaker 2: your model, then you're less likely to make mistakes. 346 00:16:04,720 --> 00:16:07,800 Speaker 1: Exactly. You can't trust those approximations forward a second or 347 00:16:07,840 --> 00:16:09,800 Speaker 1: a minute or a year, but you could trust them 348 00:16:09,800 --> 00:16:13,120 Speaker 1: like a microsecond. And so you have the simulated universe 349 00:16:13,240 --> 00:16:16,320 Speaker 1: in your computer. You feed in the initial conditions, and 350 00:16:16,360 --> 00:16:18,320 Speaker 1: then you ask it to take a step forward in time, 351 00:16:18,600 --> 00:16:20,720 Speaker 1: and you ask it to take another step forward, and 352 00:16:20,720 --> 00:16:22,680 Speaker 1: if you have enough computing power, you can run it 353 00:16:22,720 --> 00:16:25,040 Speaker 1: for a while and you can see what happens to 354 00:16:25,080 --> 00:16:27,680 Speaker 1: all my ping pong balls in my simulated swimming pool, 355 00:16:28,000 --> 00:16:30,600 Speaker 1: or what happens to my galaxy as the stars all 356 00:16:30,640 --> 00:16:31,840 Speaker 1: swirl around each other. 357 00:16:32,000 --> 00:16:35,160 Speaker 2: Right, Like you were saying, like fluids are notoriously really 358 00:16:35,240 --> 00:16:38,600 Speaker 2: hard to solve as an equation, right, These are really 359 00:16:38,640 --> 00:16:41,880 Speaker 2: complex equations that govern what's going on because they sort 360 00:16:41,880 --> 00:16:43,640 Speaker 2: of like depend on a lot of things. Like there's 361 00:16:43,640 --> 00:16:46,040 Speaker 2: a lot going on, right, there's time, and then there's 362 00:16:46,080 --> 00:16:49,080 Speaker 2: distance and the velocity of things and all those factor 363 00:16:49,160 --> 00:16:52,480 Speaker 2: in that's hard or impossible to like predict exactly what's 364 00:16:52,480 --> 00:16:53,960 Speaker 2: going to happen in the future exactly. 365 00:16:54,040 --> 00:16:57,240 Speaker 1: And the big complication there is the interactions. Like back 366 00:16:57,280 --> 00:16:58,880 Speaker 1: to the ping pong balls. If you just had a 367 00:16:58,880 --> 00:17:01,000 Speaker 1: lot of ping pong balls and they're all flying around 368 00:17:01,040 --> 00:17:03,320 Speaker 1: but not touching each other, it wouldn't be that hard 369 00:17:03,360 --> 00:17:05,960 Speaker 1: to calculate what's going to happen to each one, But 370 00:17:06,000 --> 00:17:08,160 Speaker 1: as soon as they start banging against each other, becomes 371 00:17:08,240 --> 00:17:11,040 Speaker 1: much much more complicated because the solution of ping pong 372 00:17:11,080 --> 00:17:13,879 Speaker 1: ball number six hundred and forty two now depends on 373 00:17:13,960 --> 00:17:17,040 Speaker 1: ping pong ball number one, one hundred and eleven and 374 00:17:17,160 --> 00:17:20,240 Speaker 1: every other ping pong ball, so becomes much more complicated. 375 00:17:20,320 --> 00:17:23,520 Speaker 1: And that's why fluids are so complicated, because every sheet 376 00:17:23,600 --> 00:17:25,680 Speaker 1: of the fluid depends on the friction with the other 377 00:17:25,760 --> 00:17:27,959 Speaker 1: sheet of the fluid. And that's what makes the Navier 378 00:17:28,000 --> 00:17:30,440 Speaker 1: Stokes equation, for example, so intractable. 379 00:17:30,800 --> 00:17:32,679 Speaker 2: Right, And so you take it little by little, and 380 00:17:32,720 --> 00:17:34,760 Speaker 2: so you say, okay, this time, I'm going to ignore 381 00:17:34,840 --> 00:17:37,520 Speaker 2: some of these effects and just take one small step 382 00:17:37,600 --> 00:17:40,680 Speaker 2: to see where all those little molecules go. And then 383 00:17:40,920 --> 00:17:43,960 Speaker 2: you keep repeating that and hopefully it sort of looks 384 00:17:44,080 --> 00:17:45,080 Speaker 2: like the real thing. 385 00:17:45,080 --> 00:17:48,119 Speaker 1: Exactly, and it gives you this incredible power that you 386 00:17:48,160 --> 00:17:52,240 Speaker 1: can hopefully identify emergent behavior. The way we do science 387 00:17:52,280 --> 00:17:54,560 Speaker 1: in our universe is that we like focus on one 388 00:17:54,680 --> 00:17:57,399 Speaker 1: level where we understand things we can describe, like the 389 00:17:57,440 --> 00:18:00,840 Speaker 1: microphysics of how particles being against each other. But sometimes 390 00:18:00,880 --> 00:18:03,520 Speaker 1: we're interested in things at another level, Like you understand 391 00:18:03,520 --> 00:18:05,640 Speaker 1: how rain drops move through the wind, but your real 392 00:18:05,720 --> 00:18:08,400 Speaker 1: question is like is this hurricane going to hit Florida 393 00:18:08,520 --> 00:18:10,879 Speaker 1: or Alabama? And so even if you don't have like 394 00:18:10,920 --> 00:18:13,600 Speaker 1: an equation that describes hurricanes, if you have an equation 395 00:18:13,680 --> 00:18:16,359 Speaker 1: that describes the rain drops, you can feed that all 396 00:18:16,400 --> 00:18:19,439 Speaker 1: into your computer, run simulations, and then get answers to 397 00:18:19,520 --> 00:18:22,600 Speaker 1: your higher level question. You can see like the emergent 398 00:18:22,640 --> 00:18:25,160 Speaker 1: phenomena of the hurricane in simulation. 399 00:18:25,480 --> 00:18:28,280 Speaker 2: Well, it's dig a little bit deeper into how simulation 400 00:18:28,400 --> 00:18:32,439 Speaker 2: works and the things like weather and why scientists use 401 00:18:32,480 --> 00:18:36,000 Speaker 2: simulations to try to learn things about the real universe. 402 00:18:36,240 --> 00:18:51,000 Speaker 2: But first let's take a quick break. All right, we're 403 00:18:51,000 --> 00:18:53,399 Speaker 2: having a simulation of a podcast here, right, We're not 404 00:18:53,440 --> 00:18:56,199 Speaker 2: really having a podcast, right, We're just pretending to have 405 00:18:56,240 --> 00:18:56,720 Speaker 2: a podcast. 406 00:18:56,880 --> 00:19:00,400 Speaker 1: We're simulating the process of injecting ideas into listen in our. 407 00:19:00,320 --> 00:19:03,879 Speaker 2: Minds, and so we're talking about why scientists use simulations, 408 00:19:03,920 --> 00:19:07,040 Speaker 2: and it's kind of, I guess a philosophical question, perhaps 409 00:19:07,119 --> 00:19:10,880 Speaker 2: because doing a simulation of reality is not really reality, right, 410 00:19:11,480 --> 00:19:14,760 Speaker 2: and so, and you're not really experimenting on reality. So 411 00:19:14,800 --> 00:19:16,720 Speaker 2: it's kind of a I guess, a funny thing for 412 00:19:16,800 --> 00:19:19,560 Speaker 2: scientists to do it because you're not really doing experiments 413 00:19:19,560 --> 00:19:21,360 Speaker 2: in the real world. But it's at the same time 414 00:19:21,440 --> 00:19:22,400 Speaker 2: really helpful. Right. 415 00:19:22,480 --> 00:19:24,840 Speaker 1: That's true, But that same criticism could be applied to 416 00:19:24,880 --> 00:19:28,560 Speaker 1: basically everything in science. When we do science, we never 417 00:19:28,760 --> 00:19:32,200 Speaker 1: use all of the full gory details of the universe 418 00:19:32,240 --> 00:19:35,720 Speaker 1: to answer a question. We're always using some stripped down 419 00:19:35,800 --> 00:19:39,439 Speaker 1: version because otherwise it's totally intractable. Like when we do 420 00:19:39,560 --> 00:19:42,000 Speaker 1: F equals M, even for a single ball flying through 421 00:19:42,000 --> 00:19:45,320 Speaker 1: the air, we're ignoring lots of stuff. We're ignoring air resistance, 422 00:19:45,359 --> 00:19:48,280 Speaker 1: we're ignoring quantum effects of the particles inside of it. 423 00:19:48,560 --> 00:19:50,840 Speaker 1: We're ignoring all sorts of things because we don't think 424 00:19:50,880 --> 00:19:53,480 Speaker 1: that they are important. And so every time you build 425 00:19:53,480 --> 00:19:56,880 Speaker 1: a model of the universe, theoretical or simulation, you're always 426 00:19:56,920 --> 00:19:59,280 Speaker 1: making a choice about what to ignore and what to include. 427 00:19:59,520 --> 00:20:02,160 Speaker 2: Well, we talked a lot about what a simulation is right. 428 00:20:02,200 --> 00:20:04,639 Speaker 2: It's a computer program where you program in the rules 429 00:20:04,640 --> 00:20:07,720 Speaker 2: that you think that the world follows the rules of 430 00:20:07,760 --> 00:20:09,959 Speaker 2: the universe, at least in your simulated universe, and then 431 00:20:10,000 --> 00:20:13,280 Speaker 2: you sort of let the computer kind of run this world, 432 00:20:13,480 --> 00:20:15,479 Speaker 2: and then it sort of tells you what may or 433 00:20:15,600 --> 00:20:17,560 Speaker 2: may will sort of happen. 434 00:20:17,480 --> 00:20:20,320 Speaker 1: Exactly, and it lets you examine all sorts of universes 435 00:20:20,359 --> 00:20:23,160 Speaker 1: you don't otherwise have access to, like in my work, 436 00:20:23,160 --> 00:20:25,399 Speaker 1: and let's me answer questions like what would I see 437 00:20:25,440 --> 00:20:28,919 Speaker 1: in our particle detectors if the Higgs boson was this 438 00:20:29,040 --> 00:20:31,680 Speaker 1: kind of particle, or what if there was no Higgs boson, 439 00:20:32,119 --> 00:20:34,160 Speaker 1: or what if it had twice the mass that it had? 440 00:20:34,240 --> 00:20:36,720 Speaker 1: What would we see in our detectors? What would that 441 00:20:36,800 --> 00:20:37,359 Speaker 1: universe be? 442 00:20:37,600 --> 00:20:37,719 Speaker 2: Like? 443 00:20:37,840 --> 00:20:39,600 Speaker 1: What would those experiments result in? 444 00:20:39,880 --> 00:20:42,439 Speaker 2: So it gives you ideas for experiments, or it's a 445 00:20:42,560 --> 00:20:45,480 Speaker 2: sort it can guide your real experiments. Right, that's part 446 00:20:45,520 --> 00:20:46,000 Speaker 2: of the idea. 447 00:20:46,040 --> 00:20:49,880 Speaker 1: Right, It's actually crucial for interpreting our experiments. When we 448 00:20:49,920 --> 00:20:52,040 Speaker 1: look at data from the actual collider and we see 449 00:20:52,040 --> 00:20:54,600 Speaker 1: these splashes of energy here and splashes of energy there, 450 00:20:54,600 --> 00:20:57,160 Speaker 1: and we look at the patterns the correlations. The way 451 00:20:57,200 --> 00:21:01,160 Speaker 1: we interpret those is by comparing them to simulations, we say, 452 00:21:01,720 --> 00:21:04,440 Speaker 1: is this consistent with the higgs boson with these properties 453 00:21:04,520 --> 00:21:06,240 Speaker 1: or is it more consistent with the higgs boson with 454 00:21:06,320 --> 00:21:09,760 Speaker 1: some other properties. So the simulation in some sense defines 455 00:21:09,800 --> 00:21:12,800 Speaker 1: the ideas that we're considering, the various hypotheses that we're 456 00:21:12,800 --> 00:21:14,000 Speaker 1: trying to distinguish between. 457 00:21:14,160 --> 00:21:17,120 Speaker 2: Right, It lets you explore the possibilities. That's the idea 458 00:21:17,119 --> 00:21:19,360 Speaker 2: of a simulation. Right, Let's you maybe make mistakes. 459 00:21:19,440 --> 00:21:22,200 Speaker 1: Absolutely, and before we build a detector, we simulated to 460 00:21:22,200 --> 00:21:24,880 Speaker 1: see like is this going to work or how well 461 00:21:24,960 --> 00:21:27,280 Speaker 1: is it going to perform? Or oops, turns out we 462 00:21:27,400 --> 00:21:29,439 Speaker 1: need to swap the order these two things or nothing's 463 00:21:29,480 --> 00:21:31,840 Speaker 1: going to work. So yeah, making mistakes and simulation is 464 00:21:31,920 --> 00:21:33,760 Speaker 1: much cheaper than making them in reality. 465 00:21:33,880 --> 00:21:36,040 Speaker 2: Yeah, And as you were saying, simulations play a big 466 00:21:36,080 --> 00:21:38,720 Speaker 2: part in weather prediction, right, I mean that's how weather 467 00:21:38,840 --> 00:21:41,160 Speaker 2: predictions work. Like when you look at the weather forecast 468 00:21:41,359 --> 00:21:43,640 Speaker 2: and says it's going to rain tomorrow, it's because some 469 00:21:43,680 --> 00:21:46,600 Speaker 2: big computer out there has basically taken the data from 470 00:21:46,640 --> 00:21:49,840 Speaker 2: today and simulated what's going to happen tomorrow exactly. 471 00:21:49,920 --> 00:21:54,360 Speaker 1: And that's really the origin of computer simulations. People wanted 472 00:21:54,359 --> 00:21:57,200 Speaker 1: to predict the weather, to understand what's going to happen 473 00:21:57,240 --> 00:21:59,600 Speaker 1: to these cloud patterns. But nobody could really do it 474 00:21:59,600 --> 00:22:02,720 Speaker 1: with pen and papers. Too complicated, too many pieces of information, 475 00:22:02,800 --> 00:22:05,960 Speaker 1: and the equations are really just a mess. So meteorology 476 00:22:06,000 --> 00:22:08,160 Speaker 1: is one of the first places where people decided, let's 477 00:22:08,160 --> 00:22:10,400 Speaker 1: code this up on the computer to try to grapple 478 00:22:10,480 --> 00:22:12,919 Speaker 1: with this complexity and see if we can get anything 479 00:22:13,000 --> 00:22:15,119 Speaker 1: right now, just after World War Two when computers were 480 00:22:15,160 --> 00:22:18,880 Speaker 1: first displaying like computational power, and it was the weather 481 00:22:18,920 --> 00:22:22,359 Speaker 1: forecasters and the nuclear physicists that first really jumped on 482 00:22:22,359 --> 00:22:22,800 Speaker 1: this train. 483 00:22:23,320 --> 00:22:25,359 Speaker 2: Yeah, because I think the way the weather works is 484 00:22:25,400 --> 00:22:30,119 Speaker 2: that you have all this data mateiological data, weather data 485 00:22:30,680 --> 00:22:33,480 Speaker 2: across let's say the United States, that tells you the 486 00:22:33,520 --> 00:22:36,120 Speaker 2: wind speeds and the clouds and the pressures and all that, 487 00:22:36,600 --> 00:22:38,240 Speaker 2: and then you can use it and put it into 488 00:22:38,880 --> 00:22:41,960 Speaker 2: basically your computer, which has a model of what should 489 00:22:41,960 --> 00:22:45,040 Speaker 2: happen next if that's you have all these pressures and 490 00:22:45,119 --> 00:22:46,800 Speaker 2: wind patterns exactly. 491 00:22:47,000 --> 00:22:50,160 Speaker 1: And those models are not perfect, they don't describe everything, 492 00:22:50,280 --> 00:22:53,479 Speaker 1: and so they're most reliable over short times because that's 493 00:22:53,480 --> 00:22:55,160 Speaker 1: when the errors are not going to compound as much, 494 00:22:55,320 --> 00:22:57,080 Speaker 1: which is why I like the prediction for how hot 495 00:22:57,080 --> 00:22:59,439 Speaker 1: it's going to be tomorrow is much more reliable than 496 00:22:59,440 --> 00:23:01,679 Speaker 1: the prediction for how hot it's going to be in 497 00:23:01,840 --> 00:23:05,000 Speaker 1: ten years, which you basically have no information about. Or 498 00:23:05,040 --> 00:23:07,040 Speaker 1: if you look at those projections for like where's the 499 00:23:07,119 --> 00:23:10,280 Speaker 1: hurricane going to be, the potential path of the hurricane 500 00:23:10,320 --> 00:23:13,480 Speaker 1: gets wider as the prediction gets further out because there's 501 00:23:13,480 --> 00:23:15,919 Speaker 1: more uncertainty, like is it going to hit Alabama? We 502 00:23:16,000 --> 00:23:16,400 Speaker 1: don't know. 503 00:23:16,720 --> 00:23:18,840 Speaker 2: Yeah, it's pretty cool and actually an interesting fact. I 504 00:23:18,840 --> 00:23:22,359 Speaker 2: would just talk to a hurricane scientist a couple of 505 00:23:22,400 --> 00:23:25,080 Speaker 2: months ago, and he was saying that we're still at 506 00:23:25,080 --> 00:23:30,920 Speaker 2: the point apparently where humans outperform simulations, even supercomputer simulations. 507 00:23:30,480 --> 00:23:33,080 Speaker 1: Humans using pencil and paper, or just humans like with 508 00:23:33,119 --> 00:23:34,200 Speaker 1: their intuition. 509 00:23:34,000 --> 00:23:36,800 Speaker 2: Humans with their intuition. So like, apparently we're still at 510 00:23:36,800 --> 00:23:39,560 Speaker 2: the point where if if you're seeing a hurricane move, 511 00:23:39,840 --> 00:23:41,879 Speaker 2: you run a computer simulation about where it's going to 512 00:23:41,920 --> 00:23:45,240 Speaker 2: go next. A human or like a season experienced hurricane 513 00:23:45,240 --> 00:23:48,560 Speaker 2: watcher will still today better at predicting what the hurricane 514 00:23:48,640 --> 00:23:50,240 Speaker 2: is going to do, just from like what's going on 515 00:23:50,280 --> 00:23:53,200 Speaker 2: inside their brain and the history of what they've seen before. 516 00:23:53,320 --> 00:23:56,159 Speaker 2: But it's getting apparently closer and closer, so maybe in 517 00:23:56,200 --> 00:24:00,240 Speaker 2: the near future computers will make those hurricane watchers. Is 518 00:24:00,280 --> 00:24:01,040 Speaker 2: totally obsleete. 519 00:24:01,080 --> 00:24:03,600 Speaker 1: That's super fascinating and it's fun to think about what's 520 00:24:03,640 --> 00:24:06,960 Speaker 1: going on inside that person's brain. They have built in 521 00:24:07,000 --> 00:24:11,239 Speaker 1: their head some neural network with literal biological neurons, right 522 00:24:11,240 --> 00:24:14,440 Speaker 1: and not your typical artificial neural network that models hurricanes, 523 00:24:14,480 --> 00:24:16,520 Speaker 1: and they've trained it on a bunch of real hurricanes. 524 00:24:16,800 --> 00:24:17,760 Speaker 1: So that's pretty cool. 525 00:24:18,000 --> 00:24:20,639 Speaker 2: Yeah, it makes you wonder if maybe, like in the future, 526 00:24:20,640 --> 00:24:23,800 Speaker 2: they're going to use AIS to predict the weather, maybe 527 00:24:23,800 --> 00:24:26,120 Speaker 2: you don't need a scientific model of what's going on. 528 00:24:26,240 --> 00:24:29,560 Speaker 1: That's a really fascinating question because AIS are already being 529 00:24:29,680 --> 00:24:33,840 Speaker 1: used to help boost simulations. One problem with simulations is 530 00:24:33,840 --> 00:24:37,440 Speaker 1: that they can be very expensive computationally. You have lots 531 00:24:37,440 --> 00:24:39,160 Speaker 1: and lots of rain jops and you want to model 532 00:24:39,160 --> 00:24:41,760 Speaker 1: it very, very accurately. It takes a computer a long 533 00:24:41,800 --> 00:24:44,280 Speaker 1: time to calculate every rain job and move it forward 534 00:24:44,320 --> 00:24:46,840 Speaker 1: in time. You want to predict something a few days out, 535 00:24:47,000 --> 00:24:49,600 Speaker 1: it can be very expensive computationally. We run into this 536 00:24:49,640 --> 00:24:51,640 Speaker 1: problem in particle physics all the time because we want 537 00:24:51,680 --> 00:24:54,439 Speaker 1: to simulate billions and billions of potential collisions, and the 538 00:24:54,480 --> 00:24:57,920 Speaker 1: interactions with the detector are very complicated. So to generate 539 00:24:58,000 --> 00:25:01,840 Speaker 1: one simulated collision, for example, like thirty minutes, even on 540 00:25:01,880 --> 00:25:04,639 Speaker 1: a modern computer, we use AI to boost those to 541 00:25:04,680 --> 00:25:08,840 Speaker 1: make them faster. Essentially, we train machine learning algorithms to 542 00:25:08,960 --> 00:25:13,479 Speaker 1: reproduce what the careful calculations have done. They don't understand it, 543 00:25:13,520 --> 00:25:15,880 Speaker 1: they don't like have the same equations built in. It's 544 00:25:15,880 --> 00:25:18,320 Speaker 1: just sort of like those people watching the examples and 545 00:25:18,359 --> 00:25:21,600 Speaker 1: getting an intuition. This is like a machine learning intuition. 546 00:25:22,720 --> 00:25:26,840 Speaker 2: So now you're not just similar working in a Meida world. 547 00:25:26,920 --> 00:25:29,280 Speaker 2: Now you're in twitting your way through a Meida world. 548 00:25:29,400 --> 00:25:31,520 Speaker 1: Yeah. And one problem is that we don't always know 549 00:25:31,680 --> 00:25:34,280 Speaker 1: if their predictions are accurate or why they make them. 550 00:25:34,280 --> 00:25:36,920 Speaker 1: You can't ask them like why did this go left 551 00:25:36,960 --> 00:25:39,560 Speaker 1: instead of right? They just have an internal model, the 552 00:25:39,600 --> 00:25:42,920 Speaker 1: same way your hurricane watchers probably can't answer detailed questions 553 00:25:42,960 --> 00:25:45,359 Speaker 1: about why they feel it's going this way. They just 554 00:25:45,400 --> 00:25:45,840 Speaker 1: feel it. 555 00:25:46,119 --> 00:25:50,040 Speaker 2: Yeah. And so it also raises these interesting philosophical questions 556 00:25:50,040 --> 00:25:52,720 Speaker 2: about what science is right, Like is it still science 557 00:25:52,760 --> 00:25:54,600 Speaker 2: if you get an AI to predict what's going on. 558 00:25:54,800 --> 00:25:56,680 Speaker 2: Even if you don't understand what the AI did. 559 00:25:56,840 --> 00:25:59,440 Speaker 1: It's a deep question that we're struggling with all the time. 560 00:25:59,520 --> 00:26:02,360 Speaker 1: But with no controversial is that it gives us extraordinary 561 00:26:02,400 --> 00:26:05,240 Speaker 1: power to do things we just couldn't do otherwise. We 562 00:26:05,320 --> 00:26:07,879 Speaker 1: can now run our simulations for much much longer and 563 00:26:07,920 --> 00:26:09,959 Speaker 1: in much more depth. You want to know what's going 564 00:26:10,000 --> 00:26:12,439 Speaker 1: to happen when the Milky Way collides with Andromeda or 565 00:26:12,440 --> 00:26:16,320 Speaker 1: the far future of our universe. Simulations give you that power. 566 00:26:16,560 --> 00:26:18,439 Speaker 1: You don't have to sit around and wait for the 567 00:26:18,560 --> 00:26:21,280 Speaker 1: events to play out. We can test it in simulation. 568 00:26:21,800 --> 00:26:24,439 Speaker 2: Right. That's pretty cool. And so what are the different 569 00:26:24,480 --> 00:26:26,320 Speaker 2: types of simulations that scientists use. 570 00:26:26,680 --> 00:26:29,520 Speaker 1: I would say that the simulation is almost everywhere in science. 571 00:26:29,600 --> 00:26:31,560 Speaker 1: You know, it used to be limited to a few 572 00:26:31,600 --> 00:26:36,080 Speaker 1: computationally complex fields, but now everybody sees how useful it is. 573 00:26:36,600 --> 00:26:39,119 Speaker 1: You know, even big companies like you want to design 574 00:26:39,119 --> 00:26:41,840 Speaker 1: a new airplane and you're considering a few different wing shapes. 575 00:26:42,080 --> 00:26:44,440 Speaker 1: It used to be you have to build prototypes of 576 00:26:44,480 --> 00:26:46,760 Speaker 1: those wing shapes and put them in a real huge 577 00:26:46,880 --> 00:26:50,439 Speaker 1: wind tunnel, very time consuming expensive. Now you can just 578 00:26:50,600 --> 00:26:53,440 Speaker 1: simulate the wind tunnel and get an idea for which 579 00:26:53,480 --> 00:26:55,879 Speaker 1: wing shape is going to work. You can explore thousands 580 00:26:55,880 --> 00:26:59,960 Speaker 1: of different shapes simultaneously, so that can be very very powerful. 581 00:27:00,119 --> 00:27:03,160 Speaker 1: So I think simulations are essentially everywhere in science now. 582 00:27:03,320 --> 00:27:05,760 Speaker 2: Well, I think they've been using simulations in things like 583 00:27:05,800 --> 00:27:08,720 Speaker 2: aerospace for a long time, right, Like even I'm thinking 584 00:27:08,720 --> 00:27:11,159 Speaker 2: in the space program in the fifties and sixties. I mean, 585 00:27:11,200 --> 00:27:14,560 Speaker 2: they didn't use physical computers, but they use people computers 586 00:27:14,560 --> 00:27:17,560 Speaker 2: to sort of simulate what the trajectories of the spacecraft 587 00:27:17,840 --> 00:27:18,840 Speaker 2: were going to be, right. 588 00:27:18,880 --> 00:27:22,480 Speaker 1: They definitely used human brains to do those calculations. Whether 589 00:27:22,520 --> 00:27:25,399 Speaker 1: you consider that a simulation, I think as a tricky point. 590 00:27:25,680 --> 00:27:28,960 Speaker 1: Is that just a theoretical calculation which people have been doing, 591 00:27:29,000 --> 00:27:32,320 Speaker 1: you know since Galileo or Francis Bacon or whatever. Is 592 00:27:32,359 --> 00:27:33,480 Speaker 1: it actually a simulation? 593 00:27:34,000 --> 00:27:35,879 Speaker 2: I don't know that. That's a tough question, all right, 594 00:27:35,920 --> 00:27:37,520 Speaker 2: So then what are some of the other types of 595 00:27:37,520 --> 00:27:40,639 Speaker 2: simulations people do, or what are some other ways that 596 00:27:40,720 --> 00:27:42,080 Speaker 2: physicists use simulations. 597 00:27:42,200 --> 00:27:44,960 Speaker 1: Another way they use them is to observe things that 598 00:27:45,000 --> 00:27:48,000 Speaker 1: they otherwise couldn't see, Like we want to know what's 599 00:27:48,040 --> 00:27:50,520 Speaker 1: going on inside the sun. Well, we have really no 600 00:27:50,720 --> 00:27:53,920 Speaker 1: prospects for actually seeing what's going on inside the Sun. 601 00:27:54,400 --> 00:27:56,840 Speaker 1: But we can build a simulation of the inside of 602 00:27:56,880 --> 00:27:59,360 Speaker 1: the Sun, and that's going to make predictions for things 603 00:27:59,359 --> 00:28:01,720 Speaker 1: that we can see, things happening on the surface of 604 00:28:01,760 --> 00:28:04,200 Speaker 1: the Sun, or the number of neutrinos coming to Earth, 605 00:28:04,280 --> 00:28:06,719 Speaker 1: and that helps us get an understanding for what's really 606 00:28:06,760 --> 00:28:10,600 Speaker 1: happening inside the Sun. And in the simulation, you're not limited, right, 607 00:28:10,640 --> 00:28:12,959 Speaker 1: you can ask questions about anything that's happening, like what 608 00:28:13,040 --> 00:28:14,840 Speaker 1: is the temperature or the core of the sun, what 609 00:28:15,000 --> 00:28:18,320 Speaker 1: is the velocity of the plasma. So often simulations always 610 00:28:18,400 --> 00:28:21,040 Speaker 1: checked by real experiments in places where we can observe 611 00:28:21,080 --> 00:28:24,320 Speaker 1: them give us access to things that we can't otherwise observe. 612 00:28:24,520 --> 00:28:27,200 Speaker 2: I think that's a crucial step in this process, right, 613 00:28:27,240 --> 00:28:29,439 Speaker 2: Like you can come up with this imaginary world in 614 00:28:29,480 --> 00:28:31,800 Speaker 2: your theater, but it has to match sort of what 615 00:28:31,840 --> 00:28:34,880 Speaker 2: you see at the end with reality, right absolutely. 616 00:28:34,920 --> 00:28:37,520 Speaker 1: Otherwise it's just science fiction, which you know has its 617 00:28:37,520 --> 00:28:40,600 Speaker 1: own value. But there is a special interest in our 618 00:28:40,760 --> 00:28:43,080 Speaker 1: universe and that's led to all sorts of deep understanding. 619 00:28:43,120 --> 00:28:45,440 Speaker 1: You know, the original simulations of the Sun predicted a 620 00:28:45,480 --> 00:28:48,040 Speaker 1: huge number of neutrinos landing on the surface of the Earth, 621 00:28:48,080 --> 00:28:50,120 Speaker 1: and they went out and measured them and the answer 622 00:28:50,280 --> 00:28:52,600 Speaker 1: was wrong, and they thought, did we get the sun wrong? 623 00:28:52,720 --> 00:28:55,080 Speaker 1: Or is there something going on with neutrinos? And it 624 00:28:55,120 --> 00:28:57,200 Speaker 1: turned out the simulation of the sun was correct and 625 00:28:57,280 --> 00:28:59,960 Speaker 1: neutrinos were doing something wonky between there and. 626 00:29:00,160 --> 00:29:01,920 Speaker 2: Here, right. I think the idea is that, you know, 627 00:29:01,960 --> 00:29:04,840 Speaker 2: if you create a simulation and you tweak the parameters 628 00:29:04,880 --> 00:29:07,120 Speaker 2: of it, right, like the numbers in it, so that 629 00:29:07,240 --> 00:29:09,920 Speaker 2: it matches what you see coming, for example, out of 630 00:29:09,960 --> 00:29:13,840 Speaker 2: the real Sun, then the idea is that maybe what 631 00:29:13,920 --> 00:29:15,880 Speaker 2: do you think is going on inside the sun is 632 00:29:15,920 --> 00:29:17,720 Speaker 2: actually what is going on inside the sun? 633 00:29:17,920 --> 00:29:20,680 Speaker 1: Yeah, that's exactly right. And somebody else might come up 634 00:29:20,680 --> 00:29:24,160 Speaker 1: with another simulation saying, actually, I think something else is happening. 635 00:29:24,520 --> 00:29:26,400 Speaker 1: And then you can ask, well, what's the difference between 636 00:29:26,400 --> 00:29:29,280 Speaker 1: these two simulations. Do they predict any different things that 637 00:29:29,320 --> 00:29:32,200 Speaker 1: we actually can measure that you can go off and 638 00:29:32,320 --> 00:29:35,360 Speaker 1: use that to distinguish between two various ideas. And we 639 00:29:35,440 --> 00:29:37,760 Speaker 1: talk about this all the time on the podcast. Sometimes 640 00:29:37,760 --> 00:29:40,680 Speaker 1: we have like two different possible ideas for what's happening 641 00:29:40,720 --> 00:29:43,400 Speaker 1: in near black holes. Remember we once talked about the 642 00:29:43,440 --> 00:29:46,840 Speaker 1: magnetic field near black holes something we could definitely not measure. 643 00:29:47,120 --> 00:29:49,480 Speaker 1: And there were two different models. One was called mad, 644 00:29:49,600 --> 00:29:52,680 Speaker 1: one was called sane, and they made slightly different predictions. 645 00:29:52,720 --> 00:29:55,360 Speaker 1: And then the recent picture of the black hole helped 646 00:29:55,400 --> 00:29:59,120 Speaker 1: us distinguish between these two models, these two simulations for 647 00:29:59,240 --> 00:30:00,680 Speaker 1: black hole magnet fields. 648 00:30:00,960 --> 00:30:03,120 Speaker 2: Right. But I guess that's the tricky thing, is like 649 00:30:03,400 --> 00:30:05,680 Speaker 2: just because the simulation matches what you see at the end, 650 00:30:05,840 --> 00:30:08,560 Speaker 2: it may not necessarily be what's going on inside, Right, 651 00:30:08,600 --> 00:30:11,480 Speaker 2: It could just be sort of a coincidence that it matches. 652 00:30:11,600 --> 00:30:13,520 Speaker 1: It certainly could be, And you always have to be 653 00:30:13,560 --> 00:30:16,880 Speaker 1: careful trusting your simulation. You always need ways to validate 654 00:30:16,920 --> 00:30:18,920 Speaker 1: it and to ensure that the bits that are important 655 00:30:18,920 --> 00:30:20,720 Speaker 1: to your science question are accurate. 656 00:30:20,920 --> 00:30:24,400 Speaker 2: Because I guess sometimes that's the only option that we have, right, 657 00:30:24,520 --> 00:30:27,160 Speaker 2: Like you're saying you can't just stick a stick inside 658 00:30:27,200 --> 00:30:29,959 Speaker 2: the science and see what's going on and things like 659 00:30:30,000 --> 00:30:32,640 Speaker 2: maybe black holes or the Big Bang, Like there's no 660 00:30:32,680 --> 00:30:34,720 Speaker 2: way where we can go back in time and do 661 00:30:34,760 --> 00:30:36,920 Speaker 2: an experiment on the Big Bang, Right, So we sort 662 00:30:36,920 --> 00:30:39,840 Speaker 2: of have to rely on these simulations to try to 663 00:30:39,920 --> 00:30:41,040 Speaker 2: understand what was going on. 664 00:30:41,240 --> 00:30:43,880 Speaker 1: Yeah, And they've turned out to be extraordinarily powerful tools 665 00:30:43,880 --> 00:30:45,720 Speaker 1: that give us insight into what might have happened in 666 00:30:45,760 --> 00:30:47,920 Speaker 1: the early universe or what's going on in the hearts 667 00:30:47,920 --> 00:30:50,920 Speaker 1: of black holes or neutron stars. I can't really imagine 668 00:30:50,960 --> 00:30:51,960 Speaker 1: doing science without them. 669 00:30:52,120 --> 00:30:54,360 Speaker 2: All right, Well, that's sort of what I guess a 670 00:30:54,400 --> 00:30:58,640 Speaker 2: pretty good answer for why scientists use simulations. And surprise, twist, 671 00:30:58,640 --> 00:31:02,360 Speaker 2: this whole conversation was just a simulation of our discussion 672 00:31:02,400 --> 00:31:04,840 Speaker 2: of the topic. This is like a sixth sense. I 673 00:31:04,920 --> 00:31:08,120 Speaker 2: only see simulated people. This was not the real podcast, right, Daniel. 674 00:31:08,200 --> 00:31:11,280 Speaker 1: That's right? Yeah, and hopefully this answer is also true 675 00:31:11,320 --> 00:31:12,240 Speaker 1: in the real universe. 676 00:31:12,360 --> 00:31:15,720 Speaker 2: But Daniel, you got to interview a scientist who does 677 00:31:15,760 --> 00:31:19,680 Speaker 2: physics and actually also wrote a book about simulating things 678 00:31:19,720 --> 00:31:20,440 Speaker 2: in the universe. 679 00:31:20,680 --> 00:31:23,760 Speaker 1: That's right. I had a fun chat with Professor Andrew Pnsen. 680 00:31:24,080 --> 00:31:27,520 Speaker 1: He's a cosmologist and a professor at University of College London, 681 00:31:27,560 --> 00:31:30,160 Speaker 1: and he wrote a new fun book called Universe in 682 00:31:30,200 --> 00:31:34,200 Speaker 1: a Box, which explores the role of simulation in cosmology 683 00:31:34,280 --> 00:31:36,959 Speaker 1: and in science in general. And he does have an 684 00:31:36,960 --> 00:31:39,760 Speaker 1: answer for the question is our universe a simulation? 685 00:31:40,120 --> 00:31:42,200 Speaker 2: Now? If I order Universe in a Box, do I 686 00:31:42,240 --> 00:31:43,440 Speaker 2: get a universe in a box. 687 00:31:45,680 --> 00:31:47,320 Speaker 1: Maybe you get a recipe for how to put a 688 00:31:47,400 --> 00:31:48,400 Speaker 1: universe into a box. 689 00:31:48,840 --> 00:31:51,800 Speaker 2: That's a that's not the universe in a box? And 690 00:31:51,880 --> 00:31:55,000 Speaker 2: also why a box? Why not? I don't know, as 691 00:31:55,000 --> 00:31:55,960 Speaker 2: spherical container. 692 00:31:56,040 --> 00:31:57,840 Speaker 1: I thought you were going to ask, if the universe 693 00:31:57,880 --> 00:32:00,320 Speaker 1: is in a box, what universe is the box in? 694 00:32:00,760 --> 00:32:03,120 Speaker 2: Hmmm, No, I wasn't going to ask that. 695 00:32:05,480 --> 00:32:07,840 Speaker 1: Dang it will my simulated Jorge wind Riven. 696 00:32:07,760 --> 00:32:10,360 Speaker 2: It's in the multiverse. I don't know. Aren't they like 697 00:32:10,480 --> 00:32:13,640 Speaker 2: meta universes outside of our universe? Isn't that the idea? 698 00:32:13,800 --> 00:32:16,479 Speaker 1: Click on the multiverse box option on Amazon Shipping. 699 00:32:16,560 --> 00:32:19,200 Speaker 2: The question then is can you have a multiverse in 700 00:32:19,240 --> 00:32:22,680 Speaker 2: a box? Anyways, you had a great conversation with Andrew. 701 00:32:22,840 --> 00:32:23,560 Speaker 1: I certainly did. 702 00:32:23,680 --> 00:32:25,240 Speaker 2: What motivated him to write this book. 703 00:32:25,280 --> 00:32:27,600 Speaker 1: You felt like the role of simulation in science was 704 00:32:27,760 --> 00:32:31,280 Speaker 1: super important and yet hadn't really been explored by any 705 00:32:31,320 --> 00:32:33,479 Speaker 1: pop side book, and so he wanted to share his 706 00:32:33,600 --> 00:32:36,040 Speaker 1: love for simulations with everybody. 707 00:32:36,040 --> 00:32:39,240 Speaker 2: Cool. Well, here is Daniel's interview with Professor Andrew Ponson 708 00:32:39,440 --> 00:32:42,120 Speaker 2: about his new book, Universe in a Box. 709 00:32:44,480 --> 00:32:47,480 Speaker 1: So then it's my pleasure to welcome to the program. 710 00:32:47,520 --> 00:32:52,560 Speaker 1: Andrew Ponson, a cosmologist and professor at University College London, 711 00:32:52,680 --> 00:32:54,560 Speaker 1: and youw thank you very much for joining us today. 712 00:32:54,760 --> 00:32:55,400 Speaker 3: Oh, thank you. 713 00:32:55,880 --> 00:32:59,040 Speaker 1: So your book is called Universe in a Box. It's 714 00:32:59,040 --> 00:33:02,360 Speaker 1: a fascinating and telling history and sort of definition of 715 00:33:02,400 --> 00:33:05,640 Speaker 1: what is a simulation and why it's important in science. 716 00:33:06,000 --> 00:33:09,560 Speaker 1: So let's start off with very very basics. What is 717 00:33:09,680 --> 00:33:11,600 Speaker 1: a simulation in your point of view? 718 00:33:11,720 --> 00:33:13,680 Speaker 6: There are different definitions you can give, but I think 719 00:33:13,720 --> 00:33:16,480 Speaker 6: a good place to start is by thinking it's trying 720 00:33:16,520 --> 00:33:21,600 Speaker 6: to capture some element of the real world inside a computer, 721 00:33:21,880 --> 00:33:24,640 Speaker 6: and that can take many different forms. It doesn't even 722 00:33:24,720 --> 00:33:27,480 Speaker 6: have to be a physics right, it's we can have 723 00:33:27,520 --> 00:33:31,680 Speaker 6: simulations of something like human behavior. There are simulations of 724 00:33:31,720 --> 00:33:34,840 Speaker 6: the way that crowds might behave that architects use to 725 00:33:35,120 --> 00:33:38,360 Speaker 6: make safer buildings by making the passageways the right kind 726 00:33:38,400 --> 00:33:41,400 Speaker 6: of size and shape that if there's an emergency situation, 727 00:33:41,640 --> 00:33:45,360 Speaker 6: then humans will evacuate the building in the most efficient, 728 00:33:45,440 --> 00:33:48,520 Speaker 6: safe way. But I think what that already teaches you 729 00:33:48,680 --> 00:33:51,000 Speaker 6: is that it's possible to do a simulation of something 730 00:33:51,560 --> 00:33:56,160 Speaker 6: without necessarily understanding everything about that thing before you start. 731 00:33:56,840 --> 00:34:00,240 Speaker 6: Because if you think of crowds, they're made out of people. 732 00:34:00,720 --> 00:34:04,920 Speaker 6: We can't actually predict everything about how an individual human's 733 00:34:04,960 --> 00:34:08,640 Speaker 6: going to react in any given scenario, And yet we 734 00:34:08,760 --> 00:34:12,040 Speaker 6: can make simulations that are useful. They might not be perfect, 735 00:34:12,080 --> 00:34:15,200 Speaker 6: but they're useful for giving us some insight into the 736 00:34:15,200 --> 00:34:18,319 Speaker 6: way that crowds might behave. So when you take that 737 00:34:18,360 --> 00:34:22,919 Speaker 6: across to the physics environment, and in particular my area cosmology, 738 00:34:23,560 --> 00:34:28,040 Speaker 6: it's about trying to capture something about how the universe behaves. 739 00:34:28,480 --> 00:34:30,680 Speaker 6: But we know from the outset we're never going to 740 00:34:30,719 --> 00:34:31,480 Speaker 6: get that perfect. 741 00:34:31,719 --> 00:34:34,799 Speaker 1: So then where is the value in a simulation if 742 00:34:34,840 --> 00:34:37,920 Speaker 1: you have to, like encode in already what's going to 743 00:34:37,960 --> 00:34:40,960 Speaker 1: happen when people bump into each other, or the purchasing 744 00:34:41,040 --> 00:34:44,400 Speaker 1: choices of people, or how galaxies interact. If you have 745 00:34:44,440 --> 00:34:47,000 Speaker 1: to already build in the physics, what are you learning 746 00:34:47,040 --> 00:34:49,759 Speaker 1: from the simulation? How do you get any information out 747 00:34:49,800 --> 00:34:50,000 Speaker 1: of it? 748 00:34:50,800 --> 00:34:53,879 Speaker 6: Well, the point is that you code in some things 749 00:34:53,920 --> 00:34:57,799 Speaker 6: about how the individual bits within your simulation behave. I 750 00:34:57,800 --> 00:34:59,520 Speaker 6: guess you know, in the case of the crowd that 751 00:34:59,560 --> 00:35:03,080 Speaker 6: would be how an individual human might behave under a 752 00:35:03,160 --> 00:35:06,440 Speaker 6: variety of circumstances. But in the case of physics, it 753 00:35:06,520 --> 00:35:10,239 Speaker 6: might be how we think dark matter particles flow through 754 00:35:10,239 --> 00:35:13,120 Speaker 6: the universe and interact with each other through gravity, and 755 00:35:13,160 --> 00:35:16,760 Speaker 6: what the simulation does is take a very large number 756 00:35:17,160 --> 00:35:21,120 Speaker 6: of those elements and kind of have them all individually 757 00:35:21,160 --> 00:35:25,359 Speaker 6: doing their thing. But the behavior that then emerges can 758 00:35:25,440 --> 00:35:29,280 Speaker 6: be very hard to anticipate in advance. And that's the point. 759 00:35:29,440 --> 00:35:33,120 Speaker 6: Understanding how a crowd behaves is not at all the 760 00:35:33,160 --> 00:35:36,279 Speaker 6: same thing as understanding how a human behaves, and in 761 00:35:36,320 --> 00:35:40,319 Speaker 6: the same way, understanding how dark matter behaves through our 762 00:35:40,360 --> 00:35:43,640 Speaker 6: whole cosmos is not at all the same thing as 763 00:35:43,719 --> 00:35:47,640 Speaker 6: understanding what an individual particle of dark matter might do. 764 00:35:47,920 --> 00:35:51,480 Speaker 1: This principle of emergent phenomena is something I'm super fascinated by. 765 00:35:51,920 --> 00:35:54,400 Speaker 1: It's incredible to me that sometimes we have laws of 766 00:35:54,400 --> 00:35:58,720 Speaker 1: physics at one scale, which you know, causally determine different 767 00:35:58,760 --> 00:36:01,880 Speaker 1: sort of laws of physics at another scale, which we 768 00:36:01,920 --> 00:36:04,120 Speaker 1: can't always easily predict. But as you say, we can 769 00:36:04,280 --> 00:36:07,600 Speaker 1: observe in action if we can, you know, construct the 770 00:36:07,680 --> 00:36:10,879 Speaker 1: right setup to you is simulation. Is it a kind 771 00:36:10,880 --> 00:36:13,560 Speaker 1: of experiment, Is it a kind of theory, or is 772 00:36:13,560 --> 00:36:15,720 Speaker 1: it sort of a new branch of science. 773 00:36:16,080 --> 00:36:17,839 Speaker 6: I think it's a new branch, but I think it's 774 00:36:17,880 --> 00:36:20,799 Speaker 6: got something in common with theory and with experiments, and 775 00:36:20,840 --> 00:36:23,799 Speaker 6: I guess I tilt mainly towards thinking of it as 776 00:36:23,840 --> 00:36:28,239 Speaker 6: an experiment. Now that's a little bit controversial. Sometimes people say, well, 777 00:36:28,280 --> 00:36:31,200 Speaker 6: it can't be an experiment. You've told the computer what 778 00:36:31,320 --> 00:36:34,680 Speaker 6: to do, Whereas in an experiment, you're supposed to go 779 00:36:34,719 --> 00:36:37,600 Speaker 6: and ask nature. You know, you're supposed to put things 780 00:36:37,640 --> 00:36:39,960 Speaker 6: to the test and confront them with the reality of 781 00:36:40,000 --> 00:36:41,200 Speaker 6: how things really work. 782 00:36:41,960 --> 00:36:43,759 Speaker 3: But you know, I'm not. 783 00:36:43,680 --> 00:36:46,560 Speaker 6: Sure that that distinction is always so clear. So an 784 00:36:46,600 --> 00:36:49,520 Speaker 6: example that I give in the book is, let's say 785 00:36:49,560 --> 00:36:53,680 Speaker 6: you're just trying to build an aircraft and you have 786 00:36:53,760 --> 00:36:55,919 Speaker 6: some idea about how you want to shape the wing, 787 00:36:56,400 --> 00:36:58,399 Speaker 6: but you don't know exactly how that wing is going 788 00:36:58,400 --> 00:37:01,839 Speaker 6: to perform. Now you now have a choice. You could 789 00:37:01,880 --> 00:37:05,200 Speaker 6: build a scale model of your wing and put it 790 00:37:05,239 --> 00:37:08,680 Speaker 6: inside a wind tunnel and see how it performs inside 791 00:37:08,680 --> 00:37:11,200 Speaker 6: a wind tunnel, and that's kind of an experiment. Or 792 00:37:11,640 --> 00:37:14,920 Speaker 6: you could make a digital version of your wing and 793 00:37:15,040 --> 00:37:19,000 Speaker 6: put it inside an airflow inside a computer that's a 794 00:37:19,080 --> 00:37:21,879 Speaker 6: kind of simulated airflow, and see how it behaves there. 795 00:37:22,560 --> 00:37:25,080 Speaker 6: And both of those are going to have limitations. There's 796 00:37:25,120 --> 00:37:27,920 Speaker 6: definitely limitations on what you can achieve inside the computer, 797 00:37:28,040 --> 00:37:31,440 Speaker 6: but there's also limitations in what you can achieve in 798 00:37:31,640 --> 00:37:35,360 Speaker 6: a wind tunnel. You can't make an infinitely big wind tunnel. 799 00:37:35,400 --> 00:37:37,560 Speaker 6: It's going to have edges, things are going to be 800 00:37:37,680 --> 00:37:41,799 Speaker 6: the wrong scale. So when you do experiments, you are 801 00:37:42,120 --> 00:37:46,000 Speaker 6: making some set of assumptions about the real world and 802 00:37:46,120 --> 00:37:49,400 Speaker 6: how what you're doing applies to the real world. And 803 00:37:49,480 --> 00:37:51,799 Speaker 6: I think that's just that's true in simulations as well. 804 00:37:51,920 --> 00:37:54,319 Speaker 6: So overall, this is why I start to think more 805 00:37:54,360 --> 00:37:57,440 Speaker 6: and more of simulations as types of experiment. 806 00:37:57,640 --> 00:38:00,480 Speaker 1: I have an argument with my brother who's a computer scientist, 807 00:38:00,920 --> 00:38:04,160 Speaker 1: and he runs what he calls experiments on his machine 808 00:38:04,239 --> 00:38:07,560 Speaker 1: learning models. I'm like, that's not an experiment. You're just 809 00:38:07,640 --> 00:38:10,680 Speaker 1: doing it in your computer. But you're absolutely right that 810 00:38:10,800 --> 00:38:12,560 Speaker 1: if you don't know the outcome and you're learning something, 811 00:38:12,600 --> 00:38:15,280 Speaker 1: it can be considered also an experiment. But you mentioned 812 00:38:15,280 --> 00:38:17,040 Speaker 1: something which I wanted to ask you about anyway, which 813 00:38:17,080 --> 00:38:21,239 Speaker 1: is the limitation of simulation. You're concocting sort of an 814 00:38:21,360 --> 00:38:25,319 Speaker 1: artificial universe, and you're learning something about that universe. If 815 00:38:25,320 --> 00:38:28,440 Speaker 1: that universe doesn't follow the same rules as ours, then 816 00:38:28,480 --> 00:38:31,880 Speaker 1: obviously we're not learning something about reality, which usually is 817 00:38:31,960 --> 00:38:34,799 Speaker 1: the goal. Can you say something about how we know 818 00:38:35,160 --> 00:38:39,760 Speaker 1: when to trust our simulations with the fundamental limitations of simulation. 819 00:38:39,400 --> 00:38:42,720 Speaker 6: Are yeah, I mean that is the hardest, most difficult question. 820 00:38:42,800 --> 00:38:45,799 Speaker 6: At the heart of doing good simulation is knowing what 821 00:38:45,880 --> 00:38:48,879 Speaker 6: to trust and what not to trust, and often it's hard, 822 00:38:49,080 --> 00:38:52,400 Speaker 6: you know, it can be really hard to know. I mean, fundamentally, 823 00:38:52,440 --> 00:38:57,319 Speaker 6: the limitation is just computational power that even if you're 824 00:38:57,320 --> 00:38:59,680 Speaker 6: doing something like a weather forecast, which I talk about 825 00:38:59,719 --> 00:39:03,040 Speaker 6: a bit in the book, you know, just the atmosphere 826 00:39:03,080 --> 00:39:06,360 Speaker 6: of the Earth has so many molecules in it that 827 00:39:06,440 --> 00:39:09,319 Speaker 6: you're never going to track each individual molecule, right, So 828 00:39:09,360 --> 00:39:12,160 Speaker 6: you're going to have to make some kind of approximation. 829 00:39:12,200 --> 00:39:14,920 Speaker 6: You're going to parcel up the air into almost like 830 00:39:15,000 --> 00:39:18,680 Speaker 6: big hypothetical bags of air that move around through our 831 00:39:18,719 --> 00:39:23,399 Speaker 6: atmosphere and use some laws to describe that. But then 832 00:39:23,440 --> 00:39:25,759 Speaker 6: you're going to have to go and say, well, you know, 833 00:39:25,800 --> 00:39:28,319 Speaker 6: we're not getting all the small scale details right, We're 834 00:39:28,320 --> 00:39:31,080 Speaker 6: going to have to put in some corrections. In the 835 00:39:31,120 --> 00:39:35,480 Speaker 6: case of meteorology, even clouds can be quite hard to 836 00:39:35,520 --> 00:39:38,200 Speaker 6: predict because you're just not getting all of those tiny 837 00:39:38,280 --> 00:39:41,960 Speaker 6: details that contribute to the way that a cloud forms 838 00:39:42,000 --> 00:39:44,720 Speaker 6: in reality. So you need to go in and put 839 00:39:44,920 --> 00:39:48,000 Speaker 6: into your simulation some kind of correction almost by hand. 840 00:39:48,600 --> 00:39:52,800 Speaker 6: You say, under these circumstances, clouds must start to form. 841 00:39:53,040 --> 00:39:56,520 Speaker 6: And you know, if you're a weather forecaster, you see 842 00:39:56,920 --> 00:39:59,960 Speaker 6: how well did I do by making that assumption about 843 00:40:00,120 --> 00:40:03,359 Speaker 6: how clouds form? And over time you sort of incrementally 844 00:40:03,400 --> 00:40:07,800 Speaker 6: improve by comparing how your simulation did with the reality 845 00:40:07,800 --> 00:40:10,840 Speaker 6: of how the weather unfolded. So we can do something 846 00:40:11,000 --> 00:40:13,560 Speaker 6: a bit similar in cosmology. It's not quite the same 847 00:40:13,600 --> 00:40:16,080 Speaker 6: because we don't get to kind of do the repeat 848 00:40:16,160 --> 00:40:18,320 Speaker 6: experiments in quite the same way as you do in 849 00:40:18,640 --> 00:40:21,680 Speaker 6: weather forecasting, for example. In some level, it's the same 850 00:40:21,760 --> 00:40:25,120 Speaker 6: kind of iterative process that we're getting better over time. 851 00:40:25,200 --> 00:40:28,040 Speaker 6: We're understanding the way that we have to put in 852 00:40:28,120 --> 00:40:32,440 Speaker 6: corrections to our simulations to account for things like the 853 00:40:32,480 --> 00:40:35,880 Speaker 6: way that stars evolve and change over time and dump 854 00:40:36,000 --> 00:40:39,000 Speaker 6: energy into the universe, and what black holes are up to, 855 00:40:39,080 --> 00:40:41,719 Speaker 6: and all of these things that we actually have to 856 00:40:41,960 --> 00:40:43,799 Speaker 6: help the computer along the way, if you like. 857 00:40:44,000 --> 00:40:47,080 Speaker 1: So why is it that we need to make these corrections? 858 00:40:47,160 --> 00:40:50,960 Speaker 1: We have these limitations is it purely just computational power. 859 00:40:51,320 --> 00:40:55,200 Speaker 1: In the limit of infinite computing power, could we predict 860 00:40:55,239 --> 00:40:58,560 Speaker 1: the weather tomorrow starting from particle physics and modeling every 861 00:40:58,560 --> 00:41:01,200 Speaker 1: single quirk in the atmosphe sphere, or is there a 862 00:41:01,239 --> 00:41:04,600 Speaker 1: conceptual limit there some obstacle that we can't overcome even 863 00:41:04,640 --> 00:41:05,560 Speaker 1: with infinite computing. 864 00:41:06,120 --> 00:41:07,600 Speaker 3: I think both are a problem. 865 00:41:07,760 --> 00:41:10,040 Speaker 6: So, first of all, we are very far from having 866 00:41:10,120 --> 00:41:13,400 Speaker 6: infinite computer power, a very very long way away from that. 867 00:41:13,520 --> 00:41:16,200 Speaker 6: But secondly, you're right, I mean there are more fundamental 868 00:41:16,200 --> 00:41:20,320 Speaker 6: limitations as well. In particular, we do not know exactly 869 00:41:20,360 --> 00:41:23,279 Speaker 6: where every molecule is in the atmosphere to start with. 870 00:41:24,120 --> 00:41:27,640 Speaker 6: So even if you had a computer powerful enough to 871 00:41:27,760 --> 00:41:31,160 Speaker 6: track at the molecular level what our atmosphere is doing, 872 00:41:31,400 --> 00:41:34,840 Speaker 6: you wouldn't know how to start the simulation. You wouldn't 873 00:41:34,880 --> 00:41:37,960 Speaker 6: have enough data to tell it what the atmosphere looks 874 00:41:38,000 --> 00:41:41,719 Speaker 6: like today. So there's an inaccuracy that's sort of just 875 00:41:41,800 --> 00:41:45,240 Speaker 6: coming from not having that perfect data, and an effect 876 00:41:45,560 --> 00:41:50,920 Speaker 6: known as chaos means that imperfect initial data very quickly 877 00:41:50,960 --> 00:41:55,200 Speaker 6: turns into big errors. So there's a kind of famous 878 00:41:55,320 --> 00:41:58,319 Speaker 6: example of this. It was Edward Lorenz who sort of 879 00:41:58,520 --> 00:42:03,000 Speaker 6: gave the thought experiment of butterfly flapping its wings somewhere 880 00:42:03,040 --> 00:42:06,040 Speaker 6: in Europe, say, and it has a sort of series 881 00:42:06,120 --> 00:42:09,400 Speaker 6: of knock on effects that over time just amplify and amplify, 882 00:42:09,440 --> 00:42:13,520 Speaker 6: and eventually the tiny little gust from the butterfly's wings 883 00:42:14,080 --> 00:42:19,000 Speaker 6: actually stimulates the formation of a hurricane. And you know, 884 00:42:19,080 --> 00:42:21,640 Speaker 6: these kind of effects, we know they're there, and physics 885 00:42:21,880 --> 00:42:25,359 Speaker 6: we call them chaos. And so you know, the slightest 886 00:42:26,120 --> 00:42:31,080 Speaker 6: inaccuracy in how you set things up will eventually make 887 00:42:31,120 --> 00:42:33,759 Speaker 6: the simulation depart from reality. 888 00:42:34,040 --> 00:42:35,919 Speaker 3: So we know that's true in cosmology as well. 889 00:42:36,440 --> 00:42:40,400 Speaker 6: And we don't have, you know, perfect information about the 890 00:42:40,400 --> 00:42:43,440 Speaker 6: early universe. We have quite good ideas for what was 891 00:42:43,480 --> 00:42:48,200 Speaker 6: going on there, but it's imperfect, and that means because 892 00:42:48,239 --> 00:42:51,359 Speaker 6: of chaos and the way that those imperfections are amplified 893 00:42:51,400 --> 00:42:55,239 Speaker 6: over time, what we end up with is, in some sense, 894 00:42:55,280 --> 00:42:57,480 Speaker 6: it's like a statistical. 895 00:42:56,960 --> 00:42:59,080 Speaker 3: Recreation of the universe. 896 00:42:59,120 --> 00:43:03,399 Speaker 6: It's telling us to hisstically what sorts of things should 897 00:43:03,440 --> 00:43:05,680 Speaker 6: be in the universe and what sorts of mixtures and 898 00:43:05,719 --> 00:43:09,920 Speaker 6: what kind of patterns, rather than literally recreating the universe. 899 00:43:10,000 --> 00:43:14,120 Speaker 6: So it's almost more like sort of climates, like a 900 00:43:14,200 --> 00:43:17,759 Speaker 6: climate simulation almost rather than a weather simulation. 901 00:43:18,280 --> 00:43:20,839 Speaker 1: I'm very interested in the history of simulations as well. 902 00:43:20,880 --> 00:43:24,200 Speaker 1: I mean, theoretical science is like thousands of years old. 903 00:43:24,239 --> 00:43:27,320 Speaker 1: Experimental science people argue about might be hundreds of years old. 904 00:43:27,480 --> 00:43:30,879 Speaker 1: Simulation based science seems like decades old. Can you take 905 00:43:30,960 --> 00:43:33,360 Speaker 1: us back to the root of it? Where does it begin? Really? 906 00:43:33,480 --> 00:43:33,640 Speaker 4: Well? 907 00:43:33,680 --> 00:43:35,920 Speaker 6: I think you know, the very earliest route you can 908 00:43:35,960 --> 00:43:39,320 Speaker 6: find is in the nineteenth century, where Charles Babbage and 909 00:43:39,360 --> 00:43:42,520 Speaker 6: Ada Lovelace were working on the idea of a computer 910 00:43:43,000 --> 00:43:45,960 Speaker 6: very similar to our modern computers. It was the first 911 00:43:46,000 --> 00:43:49,080 Speaker 6: time really anybody expressed the idea of having a machine 912 00:43:49,760 --> 00:43:54,800 Speaker 6: that could be told to perform any calculation. So before 913 00:43:54,880 --> 00:43:58,200 Speaker 6: that there were machines that did specific calculations, but this 914 00:43:58,360 --> 00:44:01,359 Speaker 6: was the first time somebody envisage a machine where you 915 00:44:01,360 --> 00:44:03,719 Speaker 6: could just give it instructions and it would carry out 916 00:44:04,120 --> 00:44:09,080 Speaker 6: calculations to your specifications. And Ada Lovelace actually wrote at 917 00:44:09,080 --> 00:44:12,080 Speaker 6: that time that one of the applications of being able 918 00:44:12,120 --> 00:44:15,359 Speaker 6: to do that was to be able to take what 919 00:44:15,400 --> 00:44:19,600 Speaker 6: we think are the governing laws of our physics and 920 00:44:19,680 --> 00:44:22,600 Speaker 6: make them kind of practical, you know, get the computer 921 00:44:23,280 --> 00:44:27,080 Speaker 6: to do all of the calculations that turns those abstract 922 00:44:27,120 --> 00:44:32,919 Speaker 6: equations into concrete, specific predictions for different scenarios. 923 00:44:33,160 --> 00:44:34,960 Speaker 3: So that's probably the first. 924 00:44:34,800 --> 00:44:40,040 Speaker 6: Time anyone expressed what we would recognize as a modern simulation. Then, 925 00:44:40,080 --> 00:44:44,839 Speaker 6: in terms of actually performing simulations, remarkably, some people tried 926 00:44:44,880 --> 00:44:48,600 Speaker 6: to do this in the twentieth century before digital computers 927 00:44:49,320 --> 00:44:54,680 Speaker 6: were actually made. So there are some beautiful stories like 928 00:44:56,040 --> 00:44:59,520 Speaker 6: a crazy character called Lewis Fry Richardson who was actually 929 00:45:00,080 --> 00:45:03,120 Speaker 6: on the front line of World War One trying to 930 00:45:03,719 --> 00:45:09,600 Speaker 6: calculate weather forecasts using pen and paper, very very repetitive 931 00:45:09,640 --> 00:45:12,680 Speaker 6: calculations he was doing that would be exactly what a 932 00:45:12,680 --> 00:45:15,960 Speaker 6: computer does today to do a weather forecast, but he 933 00:45:16,080 --> 00:45:19,319 Speaker 6: was doing it just with pen and paper and taking him, 934 00:45:19,320 --> 00:45:22,680 Speaker 6: you know, weeks stretching out into years just to do 935 00:45:22,760 --> 00:45:25,160 Speaker 6: one forecast. He wasn't trying to be practical about it. 936 00:45:25,160 --> 00:45:27,319 Speaker 6: He was just trying to prove a point that this 937 00:45:27,480 --> 00:45:31,680 Speaker 6: is actually doable in practice. And then you know, by 938 00:45:31,680 --> 00:45:35,680 Speaker 6: the end of World War Two there were actual computers available, 939 00:45:35,760 --> 00:45:39,280 Speaker 6: and very quickly from there the whole business of simulating 940 00:45:39,400 --> 00:45:42,760 Speaker 6: all sorts of different things, but ultimately the entire universe 941 00:45:43,080 --> 00:45:44,640 Speaker 6: kind of grew up quite quickly from there. 942 00:45:57,680 --> 00:46:00,200 Speaker 1: Tell us more about the role of simulation in or 943 00:46:00,280 --> 00:46:03,280 Speaker 1: personal research. Is this something you explore because you're fascinated 944 00:46:03,320 --> 00:46:05,400 Speaker 1: by the computer science of it, or to use it 945 00:46:05,480 --> 00:46:07,840 Speaker 1: just a tool that helps answer your physics questions. 946 00:46:08,280 --> 00:46:10,319 Speaker 6: I think it depends on the day you ask me. 947 00:46:10,400 --> 00:46:14,520 Speaker 6: I mean, some days I really enjoy the computer science 948 00:46:14,560 --> 00:46:17,440 Speaker 6: of all this, and you know, it's undeniably cool to 949 00:46:17,560 --> 00:46:20,840 Speaker 6: get to work with some of the world's biggest supercomputers 950 00:46:21,400 --> 00:46:24,319 Speaker 6: and be able to instruct them to carry out these 951 00:46:24,440 --> 00:46:28,400 Speaker 6: kind of simulations, and the results are enormous fun to 952 00:46:28,480 --> 00:46:30,400 Speaker 6: work with as well. So there is a bit of 953 00:46:30,800 --> 00:46:33,040 Speaker 6: there's a bit of that kind of nerdery in it. 954 00:46:33,080 --> 00:46:36,279 Speaker 6: But I think ultimately the thing that really keeps me 955 00:46:36,360 --> 00:46:40,440 Speaker 6: hooked is the idea that we are contributing to a 956 00:46:40,480 --> 00:46:44,760 Speaker 6: bigger picture of how our universe evolved, of the role 957 00:46:44,960 --> 00:46:49,000 Speaker 6: for materials in it that we as yet don't understand. 958 00:46:49,560 --> 00:46:51,440 Speaker 3: Things like dark matter and dark. 959 00:46:51,320 --> 00:46:54,400 Speaker 6: Energy that we know they're out there, they seem to 960 00:46:54,400 --> 00:46:57,160 Speaker 6: be having a profound effect on our universe, but we 961 00:46:57,239 --> 00:46:59,759 Speaker 6: really don't know what they are, and we're trying to 962 00:46:59,840 --> 00:47:03,279 Speaker 6: learn more about that. And then I suppose ultimately what 963 00:47:03,360 --> 00:47:06,120 Speaker 6: we're building towards is a better understanding of where we 964 00:47:06,239 --> 00:47:10,080 Speaker 6: came from. You know, the existence of us carbon based 965 00:47:10,160 --> 00:47:14,000 Speaker 6: life forms on this rocky planet is part of the 966 00:47:14,080 --> 00:47:17,680 Speaker 6: story that we're telling. Because the chemical elements from which 967 00:47:17,760 --> 00:47:21,719 Speaker 6: our planet and life are constructed weren't there in the 968 00:47:21,719 --> 00:47:25,399 Speaker 6: Big Bang. They've been manufactured over time. They need very 969 00:47:25,440 --> 00:47:30,239 Speaker 6: specific conditions to be manufactured and then concentrated enough to 970 00:47:30,920 --> 00:47:34,600 Speaker 6: start forming planets and enabling life and so on. So 971 00:47:34,800 --> 00:47:37,000 Speaker 6: I think, you know, ultimately that's the thing I'm most 972 00:47:37,000 --> 00:47:41,279 Speaker 6: excited by that we are telling this bigger story that 973 00:47:41,360 --> 00:47:43,840 Speaker 6: in the end speaks to a kind of deep question 974 00:47:43,960 --> 00:47:46,080 Speaker 6: within all of us about where did we come from? 975 00:47:46,120 --> 00:47:50,120 Speaker 1: Have you seen yet machine learning being used to amplify 976 00:47:50,400 --> 00:47:54,720 Speaker 1: or speed up, or just overall enhance simulations in your research. 977 00:47:55,480 --> 00:47:58,400 Speaker 6: Yeah, I mean machine learning is more and more important 978 00:47:58,680 --> 00:48:02,080 Speaker 6: throughout astrophysics. So it's being used in a variety of 979 00:48:02,120 --> 00:48:06,359 Speaker 6: different ways. One is to try and improve on some 980 00:48:06,440 --> 00:48:08,760 Speaker 6: of these things that we were talking about a moment 981 00:48:08,800 --> 00:48:12,399 Speaker 6: ago about you know, what do you do about the 982 00:48:12,400 --> 00:48:16,239 Speaker 6: things that you can't quite get right, Like the way 983 00:48:16,280 --> 00:48:19,759 Speaker 6: that stars form out of gas just such a complicated 984 00:48:20,440 --> 00:48:23,759 Speaker 6: process that we can't capture it perfectly the way that 985 00:48:23,760 --> 00:48:27,040 Speaker 6: those stars then put energy back into the galaxy that 986 00:48:27,080 --> 00:48:30,160 Speaker 6: they're forming within the roles of black holes, all of 987 00:48:30,200 --> 00:48:34,600 Speaker 6: these things that are very complicated and multifaceted. 988 00:48:35,239 --> 00:48:37,520 Speaker 3: We can use machine learning. 989 00:48:37,600 --> 00:48:40,760 Speaker 6: To do some of the hard work for us to 990 00:48:40,880 --> 00:48:46,440 Speaker 6: learn from examples of individual simulated stars, say about how 991 00:48:46,480 --> 00:48:49,359 Speaker 6: they behave, and kind of learn the lessons from those 992 00:48:49,400 --> 00:48:51,920 Speaker 6: and then take them and put them in the bigger 993 00:48:51,960 --> 00:48:55,120 Speaker 6: setting of trying to simulate then hundreds of billions of 994 00:48:55,160 --> 00:48:58,040 Speaker 6: stars across a galaxy or maybe you know, even out 995 00:48:58,080 --> 00:49:02,160 Speaker 6: into the universe. Sochine learning can kind of help us 996 00:49:02,400 --> 00:49:06,399 Speaker 6: take lessons from one bit of our simulations or one 997 00:49:06,440 --> 00:49:10,160 Speaker 6: bit of physics and insert them in an efficient way 998 00:49:10,280 --> 00:49:15,000 Speaker 6: into other simulations. That's one role for them, But they're 999 00:49:15,000 --> 00:49:18,400 Speaker 6: also crucial in interpreting the data we get from the 1000 00:49:18,440 --> 00:49:24,120 Speaker 6: real universe. So the data that is coming from telescopes 1001 00:49:24,360 --> 00:49:28,640 Speaker 6: and especially big new survey telescopes, things like EUCLID and 1002 00:49:29,040 --> 00:49:33,560 Speaker 6: the Verra Rubin Observatory, these giant efforts to scan the 1003 00:49:33,600 --> 00:49:37,840 Speaker 6: sky and build maps of our universe. They need machine 1004 00:49:37,880 --> 00:49:41,520 Speaker 6: learning because the machine learning can kind of do a 1005 00:49:41,560 --> 00:49:46,719 Speaker 6: lot of the initial data processing figuring out what's interesting, 1006 00:49:46,880 --> 00:49:50,319 Speaker 6: what we're actually looking at, where it is in three 1007 00:49:50,440 --> 00:49:54,320 Speaker 6: D space, and what needs to be flagged for further 1008 00:49:54,400 --> 00:49:57,320 Speaker 6: human follow up. All of these things, machine learning is 1009 00:49:57,360 --> 00:49:59,640 Speaker 6: playing an increasingly important role. 1010 00:50:00,040 --> 00:50:01,960 Speaker 1: And in your view, what does a future hold for 1011 00:50:02,160 --> 00:50:05,439 Speaker 1: simulation based science? Are there fields of science that don't 1012 00:50:05,520 --> 00:50:08,200 Speaker 1: yet use any simulation and are on the cusp of 1013 00:50:08,200 --> 00:50:10,319 Speaker 1: being revolutionized by this powerful new tool. 1014 00:50:10,600 --> 00:50:13,320 Speaker 6: I mean, I'm not aware of fields that have shied 1015 00:50:13,360 --> 00:50:16,719 Speaker 6: away from simulation. I think it is such a powerful 1016 00:50:16,760 --> 00:50:19,000 Speaker 6: tool that when you start looking for it, you do 1017 00:50:19,080 --> 00:50:22,920 Speaker 6: find it in use absolutely everywhere. But I think what 1018 00:50:22,960 --> 00:50:25,400 Speaker 6: we can say about simulation is that we're still a 1019 00:50:25,480 --> 00:50:30,080 Speaker 6: very early stage of understanding how to use simulation and 1020 00:50:30,239 --> 00:50:35,000 Speaker 6: what roles it can play within the overall scientific progress. So, 1021 00:50:35,280 --> 00:50:37,120 Speaker 6: you know, it goes all the way back to what 1022 00:50:37,200 --> 00:50:39,759 Speaker 6: really is a simulation? Is it an experiment or is 1023 00:50:39,800 --> 00:50:43,759 Speaker 6: it a calculation? How should we think about it? And 1024 00:50:43,840 --> 00:50:46,600 Speaker 6: tied up with that is this question of how can 1025 00:50:46,640 --> 00:50:49,640 Speaker 6: we improve our simulations? How do we get past that 1026 00:50:49,800 --> 00:50:53,080 Speaker 6: stage of well, we just have to kind of play 1027 00:50:53,120 --> 00:50:56,200 Speaker 6: around with things and tweak them till they fit because 1028 00:50:56,520 --> 00:51:00,719 Speaker 6: of the intrinsic limitations. So I think we're at a 1029 00:51:00,840 --> 00:51:03,600 Speaker 6: very early stage in understanding all of these things. So 1030 00:51:04,520 --> 00:51:07,640 Speaker 6: for certain the role that simulations play is going to 1031 00:51:07,920 --> 00:51:12,240 Speaker 6: change and evolve and I hope improve over the coming years. 1032 00:51:12,600 --> 00:51:15,800 Speaker 1: So if you use the words universe and simulation together 1033 00:51:15,840 --> 00:51:18,200 Speaker 1: in a sentence, that of course evokes in people's minds 1034 00:51:18,239 --> 00:51:21,320 Speaker 1: this conversation that seems to be omnipresent, which is, you 1035 00:51:21,360 --> 00:51:24,080 Speaker 1: know whether or not our universe could be a simulation 1036 00:51:24,400 --> 00:51:27,759 Speaker 1: or the same question sort of when we build artificial 1037 00:51:27,840 --> 00:51:31,360 Speaker 1: universes that have bits and pieces in it, could those 1038 00:51:31,480 --> 00:51:34,799 Speaker 1: universes feel real to those occupants. So in your book, 1039 00:51:34,840 --> 00:51:36,919 Speaker 1: you take a sort of skeptical view of the question 1040 00:51:37,000 --> 00:51:39,600 Speaker 1: of whether we could be living in a simulation. Since 1041 00:51:39,600 --> 00:51:42,440 Speaker 1: you're an expert on simulating universes, what are your arguments 1042 00:51:42,480 --> 00:51:44,800 Speaker 1: against the concept that we could be living in a simulation. 1043 00:51:45,160 --> 00:51:47,560 Speaker 6: Yeah, I think the primary argument is just to look 1044 00:51:47,560 --> 00:51:51,040 Speaker 6: at the complexity of the universe that we're in. So 1045 00:51:51,120 --> 00:51:54,440 Speaker 6: you can actually calculate something called the number of cubits, 1046 00:51:54,600 --> 00:51:57,680 Speaker 6: so basically the number of quantum bits that you would 1047 00:51:57,719 --> 00:52:00,120 Speaker 6: need in a quantum computer if you wanted to do 1048 00:52:00,640 --> 00:52:03,680 Speaker 6: according to all the physics we know so far, if 1049 00:52:03,680 --> 00:52:07,400 Speaker 6: you wanted to do a perfect simulation of our universe, 1050 00:52:07,760 --> 00:52:10,120 Speaker 6: and that is a vast number. I forget it off 1051 00:52:10,160 --> 00:52:11,400 Speaker 6: the top of my head. I think it's something like 1052 00:52:11,440 --> 00:52:13,920 Speaker 6: ten to the one hundred and twenty four cubits. 1053 00:52:13,920 --> 00:52:16,960 Speaker 3: It's something like that. It's a very very large number. 1054 00:52:17,280 --> 00:52:19,879 Speaker 6: And right now, you know, we struggle even to make 1055 00:52:19,920 --> 00:52:23,600 Speaker 6: a single cubit in a quantum computer. It's a vast 1056 00:52:23,640 --> 00:52:26,879 Speaker 6: extrapolation from where we are now to the idea that 1057 00:52:27,400 --> 00:52:31,440 Speaker 6: we will routinely be able to run simulations that have 1058 00:52:31,560 --> 00:52:35,480 Speaker 6: the same kind of richness as the reality that we 1059 00:52:35,560 --> 00:52:36,359 Speaker 6: currently live in. 1060 00:52:36,640 --> 00:52:40,360 Speaker 3: But even more than that. If you ask, well, you know, what. 1061 00:52:40,280 --> 00:52:44,600 Speaker 6: Resources would you need to build a computer that really 1062 00:52:44,640 --> 00:52:49,200 Speaker 6: had that level of capability, Well, it turns out you 1063 00:52:49,239 --> 00:52:53,120 Speaker 6: would need to make use of the entire universe just 1064 00:52:53,160 --> 00:52:59,000 Speaker 6: to simulate one universe. Because physics puts limitations on information processing. 1065 00:52:59,080 --> 00:53:02,960 Speaker 6: You can't process as much information as you like. There 1066 00:53:02,960 --> 00:53:06,080 Speaker 6: are limitations placed on it according to the physical system 1067 00:53:06,120 --> 00:53:08,719 Speaker 6: that it's being processed by, and so these come back 1068 00:53:08,760 --> 00:53:12,120 Speaker 6: to bite you. So and that's what gives rise to 1069 00:53:13,120 --> 00:53:16,080 Speaker 6: this claim that you can only simulate the whole universe 1070 00:53:16,520 --> 00:53:20,280 Speaker 6: perfectly if you have access to the entire physical resources 1071 00:53:20,560 --> 00:53:24,480 Speaker 6: of that universe. Now, there are lots of further objections 1072 00:53:24,520 --> 00:53:27,120 Speaker 6: you can raise. You can say, well, what about, for example, 1073 00:53:27,400 --> 00:53:32,000 Speaker 6: if the higher up universe where we're being simulated is 1074 00:53:32,160 --> 00:53:35,960 Speaker 6: just a much bigger universe with many more cubits at 1075 00:53:35,960 --> 00:53:40,240 Speaker 6: their disposal, and so these resources seem terribly trivial maybe 1076 00:53:40,280 --> 00:53:43,120 Speaker 6: to the people in the higher up universe. But at 1077 00:53:43,120 --> 00:53:45,720 Speaker 6: that point I kind of lose patience with the argument, 1078 00:53:45,880 --> 00:53:48,839 Speaker 6: because it seems to me, at that point we it's 1079 00:53:48,920 --> 00:53:52,040 Speaker 6: no longer a sort of obvious extrapolation from where we are. 1080 00:53:52,080 --> 00:53:56,479 Speaker 6: Now you're now talking about hypothesizing beings with so much 1081 00:53:56,520 --> 00:54:00,640 Speaker 6: more power and so much more technological capability than we have, 1082 00:54:01,160 --> 00:54:03,920 Speaker 6: that we might as well just go and talk about religion, 1083 00:54:04,120 --> 00:54:07,080 Speaker 6: because at this point it's lost contact, in my view, 1084 00:54:07,200 --> 00:54:08,320 Speaker 6: with any science. 1085 00:54:09,760 --> 00:54:12,880 Speaker 1: Wonderful. Well, I really enjoyed your book, And a question 1086 00:54:12,960 --> 00:54:15,839 Speaker 1: I always have for folks who write popular science books 1087 00:54:16,000 --> 00:54:20,080 Speaker 1: about very technical topics is why what do you think 1088 00:54:20,120 --> 00:54:22,840 Speaker 1: that the general public, folks out there who are not 1089 00:54:23,320 --> 00:54:26,480 Speaker 1: simulation experts need to know about simulation? 1090 00:54:27,120 --> 00:54:28,560 Speaker 3: I think there were two reasons. 1091 00:54:28,640 --> 00:54:31,360 Speaker 6: The first was it was amazing to me that nobody 1092 00:54:31,440 --> 00:54:34,760 Speaker 6: had written about this topic before because it's so central 1093 00:54:34,960 --> 00:54:38,239 Speaker 6: in our field of cosmology, and you know, cosmology is 1094 00:54:38,280 --> 00:54:40,719 Speaker 6: something that people do talk about a lot. There's a 1095 00:54:40,760 --> 00:54:43,120 Speaker 6: lot of it out there in the media and in books, 1096 00:54:43,680 --> 00:54:46,120 Speaker 6: because it's genuinely you know, it's exciting, and I think 1097 00:54:46,239 --> 00:54:48,840 Speaker 6: it speaks to all of us about where we came from. 1098 00:54:49,239 --> 00:54:51,799 Speaker 6: And so it seems a real surprise to me that 1099 00:54:51,920 --> 00:54:55,280 Speaker 6: this central tool in how we're learning about the universe 1100 00:54:55,760 --> 00:54:57,880 Speaker 6: was not being written about, and so it felt to 1101 00:54:57,880 --> 00:55:00,160 Speaker 6: me like it needs to be rectified. We need to 1102 00:55:00,160 --> 00:55:04,000 Speaker 6: be talking about this because it offers immense strengths, you know, 1103 00:55:04,400 --> 00:55:08,880 Speaker 6: real enormous strengths that I think are kind of hidden 1104 00:55:08,880 --> 00:55:12,040 Speaker 6: away sometimes. But it also comes with lots of caveats, 1105 00:55:12,040 --> 00:55:14,960 Speaker 6: some of them we've discussed. You know that we can't 1106 00:55:15,040 --> 00:55:18,040 Speaker 6: do these perfect recreations of the universe. There are lots 1107 00:55:18,080 --> 00:55:21,319 Speaker 6: of approximations. We might be making mistakes, and you know, 1108 00:55:21,600 --> 00:55:23,439 Speaker 6: there's no way to rule that out. It's just part 1109 00:55:23,440 --> 00:55:26,440 Speaker 6: of the scientific process that we have to keep an 1110 00:55:26,440 --> 00:55:29,399 Speaker 6: open mind about these things. So I wanted to write 1111 00:55:29,440 --> 00:55:32,120 Speaker 6: about that in a kind of open and honest way, 1112 00:55:32,640 --> 00:55:36,600 Speaker 6: rather than sort of leaving the simulations as black boxes 1113 00:55:36,640 --> 00:55:40,759 Speaker 6: that seemingly recreate our universe through some process of magic. No, 1114 00:55:40,880 --> 00:55:44,840 Speaker 6: it's a very human process and it's got all of 1115 00:55:44,840 --> 00:55:47,719 Speaker 6: the strengths and weaknesses that come with being that kind 1116 00:55:47,760 --> 00:55:48,680 Speaker 6: of human process. 1117 00:55:49,080 --> 00:55:53,000 Speaker 1: Wonderful. Well, thank you very much again. Professor Andrew Hanson 1118 00:55:53,000 --> 00:55:55,479 Speaker 1: at University of College London and author of the book 1119 00:55:55,680 --> 00:55:59,080 Speaker 1: The Universe in a Box Out now encourage everyone to 1120 00:55:59,160 --> 00:56:03,239 Speaker 1: go out and about how science is actually done. Thanks 1121 00:56:03,280 --> 00:56:05,040 Speaker 1: again very much Andrew for joining us today. 1122 00:56:05,719 --> 00:56:07,600 Speaker 2: All Right, did you feel you had a real conversation 1123 00:56:07,680 --> 00:56:10,520 Speaker 2: with him, Like, did things get real or was it 1124 00:56:10,560 --> 00:56:12,279 Speaker 2: all just simulated pleasantries? 1125 00:56:12,480 --> 00:56:17,520 Speaker 1: I was able to simulate enjoying a conversation. Yeah. Oh 1126 00:56:17,680 --> 00:56:20,040 Speaker 1: that's sort of always my situation though, because I'm kind 1127 00:56:20,080 --> 00:56:23,200 Speaker 1: of an introvert, so I have to simulate enjoying human interactions. 1128 00:56:23,480 --> 00:56:26,359 Speaker 2: Yet you have to simulate being engaging human being. 1129 00:56:27,040 --> 00:56:29,800 Speaker 1: I'm trying to quietly slip unnoticed into human society. 1130 00:56:29,920 --> 00:56:31,960 Speaker 2: So you are a simulation, Daniel. 1131 00:56:32,719 --> 00:56:34,040 Speaker 1: I'm simulating being a human. 1132 00:56:34,200 --> 00:56:37,000 Speaker 2: But anyways, that was a great conversation. What's your main 1133 00:56:37,040 --> 00:56:37,719 Speaker 2: takeaway from it? 1134 00:56:37,760 --> 00:56:40,440 Speaker 1: To me, it's fascinating that so recently in the history 1135 00:56:40,480 --> 00:56:43,120 Speaker 1: of science, just the last few decades, we've developed this 1136 00:56:43,200 --> 00:56:46,560 Speaker 1: crucial new tool that we now think is indispensable. It 1137 00:56:46,600 --> 00:56:49,160 Speaker 1: makes me wonder in fifty years and one hundred years, 1138 00:56:49,200 --> 00:56:52,040 Speaker 1: what new branch of science or what new tool we're 1139 00:56:52,080 --> 00:56:55,480 Speaker 1: going to add to our toolbox which future scientists will 1140 00:56:55,480 --> 00:56:58,600 Speaker 1: think is indispensable, And we'll wonder, like, how did Daniel 1141 00:56:58,680 --> 00:57:01,360 Speaker 1: and folks who lived way back then do any science 1142 00:57:01,400 --> 00:57:01,839 Speaker 1: without it? 1143 00:57:02,080 --> 00:57:05,040 Speaker 2: Or maybe even like why did Daniel do science? Why 1144 00:57:05,040 --> 00:57:09,480 Speaker 2: didn't they choose use the AI physicists to answer all 1145 00:57:09,480 --> 00:57:09,960 Speaker 2: the questions? 1146 00:57:10,040 --> 00:57:12,080 Speaker 1: Yeah, stay in bed and let the AIS do the work. 1147 00:57:12,480 --> 00:57:14,560 Speaker 1: The answer to that is the AIS wan't answer questions 1148 00:57:14,560 --> 00:57:17,800 Speaker 1: the AIS are interested in and science is for people, 1149 00:57:17,880 --> 00:57:20,080 Speaker 1: by people, and of people, So you got to have 1150 00:57:20,160 --> 00:57:21,360 Speaker 1: people asking questions. 1151 00:57:21,480 --> 00:57:23,200 Speaker 2: Wait, wait, do you mean the AIS won't always do 1152 00:57:23,240 --> 00:57:24,080 Speaker 2: what we ask them to do. 1153 00:57:25,920 --> 00:57:28,880 Speaker 1: They'll always do exactly what we ask them to do, 1154 00:57:28,920 --> 00:57:30,640 Speaker 1: just not and maybe in the way that we want 1155 00:57:30,680 --> 00:57:30,920 Speaker 1: them to. 1156 00:57:31,320 --> 00:57:34,680 Speaker 2: All right, Well, stay tuned to see if we are 1157 00:57:34,680 --> 00:57:37,680 Speaker 2: in a simulation right now? Maybe I guess some people 1158 00:57:37,760 --> 00:57:39,480 Speaker 2: consider the whole universe to be service. 1159 00:57:39,240 --> 00:57:41,280 Speaker 1: Simulation, right, how can we possibly know? 1160 00:57:41,640 --> 00:57:43,360 Speaker 2: Yeah, Like, what's the difference if. 1161 00:57:43,200 --> 00:57:45,960 Speaker 1: We are in a vast alien simulation. Then I definitely 1162 00:57:46,000 --> 00:57:47,880 Speaker 1: want to talk to those aliens because they have some 1163 00:57:48,040 --> 00:57:49,600 Speaker 1: awesome computers. 1164 00:57:49,360 --> 00:57:52,200 Speaker 2: And also to stay tuned about what new developments humans 1165 00:57:52,200 --> 00:57:56,240 Speaker 2: are going to discover using simulations and or artificial intelligence. 1166 00:57:56,480 --> 00:57:58,600 Speaker 2: So we hope you enjoyed that. Thanks for joining us, 1167 00:57:59,280 --> 00:58:00,000 Speaker 2: see you next time. 1168 00:58:07,800 --> 00:58:10,600 Speaker 1: Thanks for listening, and remember that Daniel and Jorge Explain 1169 00:58:10,680 --> 00:58:14,680 Speaker 1: the Universe is a production of iHeartRadio. For more podcasts 1170 00:58:14,680 --> 00:58:19,320 Speaker 1: from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever 1171 00:58:19,400 --> 00:58:21,120 Speaker 1: you listen to your favorite shows.