WEBVTT - How do we know quantum mechanics is really random? 0:00:08.440 --> 0:00:10.480 Hey, Daniel, do you have a pretty good routine? You 0:00:10.480 --> 0:00:13.360 mean like a dance routine or like ten tight minutes 0:00:13.360 --> 0:00:16.159 of stand up comedy? I mean like a schedule, Like 0:00:16.239 --> 0:00:18.239 do you have the same day plant every day? Or 0:00:18.320 --> 0:00:20.800 do you wing it every day? Yeah? I'm pretty into 0:00:20.840 --> 0:00:23.000 my schedules. It's the only way I can really stay 0:00:23.000 --> 0:00:25.440 on top of everything. Oh man, that is the opposite 0:00:25.480 --> 0:00:27.440 of what I do. I like to wake up every 0:00:27.520 --> 0:00:29.920 day not knowing what's gonna happen. Well, I like to 0:00:29.960 --> 0:00:32.280 plan every day, but in the end, every day turns 0:00:32.280 --> 0:00:35.280 out totally different because my well laid plans get blown 0:00:35.360 --> 0:00:38.440 up by something that happens. See, so what's the point 0:00:38.440 --> 0:00:41.159 of making plans. I like to live in a superposition 0:00:41.200 --> 0:00:45.720 of organization and chaos. So you're both or neither depends 0:00:45.720 --> 0:00:47.879 on which day you collapse my wave function and on 0:00:47.920 --> 0:00:50.479 which day my schedule collapses. Sounds like you're the one 0:00:50.520 --> 0:00:52.319 who collapses at the end of the day, though. That's 0:00:52.320 --> 0:01:09.640 how you know him a true quantum mechanic. Hi am 0:01:09.760 --> 0:01:11.720 or Him and Cartoonists, and the co author of Frequently 0:01:11.760 --> 0:01:14.959 Asked Questions about the Universe. Hi, I'm Daniel. I'm a 0:01:15.000 --> 0:01:18.080 particle physicist. And a professor at U C Irvine, And 0:01:18.200 --> 0:01:21.959 I'm supposed to understand quantum mechanics. You're supposed to do that, 0:01:22.040 --> 0:01:24.560 I guess because you're a physicist, right, that's right, it's 0:01:24.600 --> 0:01:28.840 my official job. Particles are definitely quantum objects, and yet 0:01:28.920 --> 0:01:32.280 it's still something that everybody in the field struggles with. 0:01:32.400 --> 0:01:35.800 But didn't Richard Fine when famously said that nobody understands 0:01:35.880 --> 0:01:38.320 quantum mechanics and if you do, then you don't really 0:01:38.360 --> 0:01:40.479 understand it. And he was one of the top five 0:01:40.560 --> 0:01:43.600 smartest physicists. So yeah, everybody below him on the ranking 0:01:43.959 --> 0:01:47.039 can't understand it better than he does. With the top four, dude, 0:01:49.160 --> 0:01:50.560 I think there are a few people out there that 0:01:50.720 --> 0:01:53.680 might understand quantum mechanics better than Richard Fineman. Yeah. Do 0:01:53.680 --> 0:01:56.320 you think it's maybe just a limitation of the human 0:01:56.360 --> 0:01:59.760 brain or is the quantum mechanics use there not understandable. 0:01:59.840 --> 0:02:02.640 I think we definitely can understand the mathematics of it, 0:02:02.680 --> 0:02:08.440 but sometimes translating that mathematics into intuition is really complicated. 0:02:08.800 --> 0:02:12.799 It's hard to understand things which are very unfamiliar to us. 0:02:13.320 --> 0:02:15.959 Because in the end, physics is about trying to explain 0:02:16.200 --> 0:02:19.640 the unfamiliar in terms of the familiar. But sometimes we 0:02:19.760 --> 0:02:23.440 don't have a good intuitive analog to reach for. Sometimes 0:02:23.440 --> 0:02:26.720 we find something which really is very different from anything 0:02:26.760 --> 0:02:29.720 we've experienced before. That's why I don't believe in intuition, 0:02:29.760 --> 0:02:33.600 either schedules and intuitions. I just leave him at home 0:02:33.639 --> 0:02:36.519 every day. But anyways, welcome to our podcast Daniel and 0:02:36.560 --> 0:02:39.400 Jorge Explained the Universe, a production of My Heart Radio 0:02:39.520 --> 0:02:42.959 in which we attempt to apply our intuition to understanding 0:02:43.040 --> 0:02:46.720 everything about the universe. For these little squishy brains that 0:02:46.800 --> 0:02:49.720 evolved on this one rock around one planet. It's an 0:02:49.760 --> 0:02:53.679 incredible task to try to understand everything that's out there, 0:02:53.800 --> 0:02:58.079 including phenomena that our ancestors never saw, crazy black holes, 0:02:58.120 --> 0:03:01.919 incredibly dense neutron stars, any buzzing particles. Is it even 0:03:01.919 --> 0:03:04.680 possible to grop all of that, to import it somehow 0:03:04.720 --> 0:03:07.640 into our minds so we can play with it, manipulated 0:03:07.880 --> 0:03:10.640 and understand it. That's right, because it is a vast 0:03:10.680 --> 0:03:13.959 and incredible universe full of amazing things that run counter 0:03:14.040 --> 0:03:17.239 to our intuitions sometimes and that are very difficult to understand. 0:03:17.360 --> 0:03:19.240 And so the only thing we can schedule on this 0:03:19.320 --> 0:03:22.400 podcast is the idea that we're gonna talk about it 0:03:22.600 --> 0:03:24.960 and try to understand it and ask questions about it. 0:03:25.080 --> 0:03:27.400 Because on the podcast we try to do something which 0:03:27.480 --> 0:03:31.880 may be impossible, which is to translate all of these ideas, 0:03:32.160 --> 0:03:36.720 which in the end are expressed mathematically, into concepts that 0:03:36.760 --> 0:03:39.480 we can deliver into your brain just with chit chat 0:03:39.600 --> 0:03:42.360 and conversation. It's not always easy to know how to 0:03:42.520 --> 0:03:47.440 transform these ideas from their essential mathematical principles into an 0:03:47.440 --> 0:03:50.400 intuitive understanding, a stream of words which land in your 0:03:50.440 --> 0:03:53.040 ear and build in your mind a little model that 0:03:53.080 --> 0:03:55.680 makes you go, oh, I get it. But that's what 0:03:55.720 --> 0:03:58.200 we're going for. Yeah, it's a pretty challenging problem if 0:03:58.200 --> 0:03:59.720 you think about it, right, because we're trying to take 0:03:59.720 --> 0:04:03.280 the higher universe, which is at least four dimensions, maybe more, 0:04:03.520 --> 0:04:06.640 and we're trying to get it down to really one dimension, right, 0:04:06.680 --> 0:04:10.760 because audio is just one one degree of freedom, right, 0:04:10.840 --> 0:04:13.120 I suppose though, although in principle there are an infinite 0:04:13.200 --> 0:04:16.480 number of frequencies along which to convey information. But yeah, 0:04:16.480 --> 0:04:19.080 that's a good point. We're trying to like serialize the 0:04:19.160 --> 0:04:23.279 universe into a stream of information which unpacks itself into 0:04:23.320 --> 0:04:25.760 your mind to give you a mental model of the 0:04:25.839 --> 0:04:28.640 universe that somehow works. I guess it would help if 0:04:28.640 --> 0:04:31.240 maybe we're recording stereo, like I could be on people's 0:04:31.320 --> 0:04:33.279 left ear and you could be on people's right ear, 0:04:33.600 --> 0:04:35.839 and then we could maybe convey more information that way, 0:04:35.960 --> 0:04:38.280 like a little angel and devils standing on your shoulders. 0:04:38.440 --> 0:04:42.000 Or maybe we need to cartoonists and to physicists going simultaneously. 0:04:42.880 --> 0:04:45.760 How does that help, and we're all talking at the 0:04:45.800 --> 0:04:50.039 same time exactly, it would be two dimensional podcasting simultaneously. 0:04:50.200 --> 0:04:52.760 I feel like you would still collapse right under the 0:04:52.800 --> 0:04:55.640 amount of information. You're still collapsing the information down to 0:04:55.960 --> 0:04:58.600 one dimensional audio. Yeah. I think probably it's best to 0:04:58.640 --> 0:05:01.280 stick with one dimension and do best to project these 0:05:01.320 --> 0:05:05.120 crazy ideas down into a one dimensional audio stream. It 0:05:05.160 --> 0:05:09.200 is a complex universe, and sometimes it's a seemingly random universe. 0:05:09.520 --> 0:05:11.480 It's a huge universe, and all kinds of things are 0:05:11.520 --> 0:05:13.279 happening in it, and it's not quite clear where the 0:05:13.360 --> 0:05:16.920 things are happening according to a plan or if they 0:05:16.960 --> 0:05:19.960 are just randomly occurring in the universe. Yeah. One of 0:05:19.960 --> 0:05:23.279 the most fundamental questions about the nature of the universe 0:05:23.560 --> 0:05:26.320 is whether you can predict what's going to happen in 0:05:26.360 --> 0:05:29.760 the future based on the past. Is the universe like 0:05:29.880 --> 0:05:32.359 a big clock, where if you understood all of the 0:05:32.440 --> 0:05:35.320 rules and had enough information, you could tell exactly what 0:05:35.400 --> 0:05:38.640 was going to happen? Or fundamentally, is there something weird 0:05:38.760 --> 0:05:41.200 going on at the heart of the machine that is 0:05:41.279 --> 0:05:44.640 running the universe, something different from anything we have ever 0:05:44.800 --> 0:05:49.200 experienced directly, something truly random? And well, I guess the 0:05:49.279 --> 0:05:51.680 universe seems pretty random, right, Like if I flip a coin, 0:05:51.880 --> 0:05:53.680 it's really hard to tell if it's going to be 0:05:53.680 --> 0:05:56.240 heads or tails. Right, it does, And we often use 0:05:56.320 --> 0:05:59.520 flipping a coin or rolling a dice as an approximation 0:05:59.600 --> 0:06:03.160 for some random But those are not actually random processes. 0:06:03.240 --> 0:06:07.320 Those are just very very complicated processes, things which are 0:06:07.360 --> 0:06:11.200 hard to predict, but in principle possible to predict if 0:06:11.240 --> 0:06:15.080 you had enough information and enough computer processing power. What 0:06:15.120 --> 0:06:17.160 about whether we're going to explain something well or not? 0:06:17.279 --> 0:06:21.039 Isn't that also kind of random? Hey, sometimes what we 0:06:21.080 --> 0:06:23.320 talk about on the podcast feels a little random. You know, 0:06:23.360 --> 0:06:25.480 I'll prepare a whole outline and we'll never get past 0:06:25.520 --> 0:06:27.480 the first bit. Wait, are you saying I'm the random 0:06:27.520 --> 0:06:31.080 filter here? I'm saying that Daniel Jorge interaction is a 0:06:31.120 --> 0:06:34.240 little unpredictable. Sometimes what we end up talking about in 0:06:34.279 --> 0:06:36.880 the best possible way. I love those episodes when you're 0:06:36.880 --> 0:06:39.280 like a whole lot of second, slow down, what does 0:06:39.320 --> 0:06:41.679 that actually mean? And then we spend forty five minutes 0:06:41.800 --> 0:06:44.040 talking about the definition. We may we just need like 0:06:44.080 --> 0:06:46.640 a parallel podcast or something. Maybe we need the multi 0:06:46.680 --> 0:06:49.479 World's podcast where we take every possible branch and every 0:06:49.480 --> 0:06:53.159 possible digression simultaneously. Well, this idea of whether the universe 0:06:53.240 --> 0:06:55.320 is random or not with something that sort of came 0:06:55.360 --> 0:06:58.160 up recently in the last hundred or two hundred years, right, 0:06:58.279 --> 0:07:00.880 I mean, after Newton, people have figured that the universe 0:07:00.920 --> 0:07:04.440 was pretty mechanical, pretty much like a machine where everything 0:07:04.480 --> 0:07:06.919 followed F equals m A, and you could predict what 0:07:07.240 --> 0:07:10.640 the path of a baseball or dropping a coin, what 0:07:10.680 --> 0:07:12.520 was going to happen. You could predict that. But then 0:07:12.600 --> 0:07:15.520 came quantum mechanics, who said, well, maybe things are not 0:07:15.600 --> 0:07:19.280 that predictable. Yeah, And both of those really are revolutions 0:07:19.400 --> 0:07:22.000 in our understanding of how the universe works. I mean, 0:07:22.040 --> 0:07:25.080 before quantum mechanics, even just the idea that the universe 0:07:25.240 --> 0:07:28.760 was deterministic, that it was like clockwork, that the whole 0:07:28.840 --> 0:07:33.160 apparatus of reality was somehow following physical laws which you 0:07:33.200 --> 0:07:36.160 could uncover and understand and used to predict the future. 0:07:36.480 --> 0:07:39.600 This was a big idea, right. This flew in the 0:07:39.600 --> 0:07:42.480 face of lots of people sort of spiritual sense that 0:07:42.520 --> 0:07:45.800 there was somebody out there, unpredictable, in control of the universe. 0:07:46.080 --> 0:07:48.520 To reduce it to a set of natural laws which 0:07:48.560 --> 0:07:51.120 governed it, that was a big step forward. And so 0:07:51.200 --> 0:07:54.840 then to pull the rug out from underneath that and say, actually, no, 0:07:55.280 --> 0:07:57.320 at the heart of all of it, there might be 0:07:57.400 --> 0:08:01.960 something unpredictable, some process which determines the outcome but isn't 0:08:02.080 --> 0:08:06.080 determined by the past, is somehow fundamentally random. That was 0:08:06.120 --> 0:08:08.320 a crazy, big new idea. Yeah, I guess it was 0:08:08.360 --> 0:08:11.400 a double sweeping of the rug, right, because before Newton, 0:08:11.480 --> 0:08:15.280 I guess, and before these fundamental laws of the universe, 0:08:15.320 --> 0:08:18.080 people kind of thought the universe was random. Right. It 0:08:18.160 --> 0:08:20.240 was random, or at least at the whim of some 0:08:20.400 --> 0:08:23.640 gods or some deity that sort of randomly decided things. 0:08:23.720 --> 0:08:25.920 And then we thought it was all ordered, and then 0:08:25.960 --> 0:08:28.880 we realized, wait, it is sort of random. Yeah, exactly 0:08:28.960 --> 0:08:31.679 though random in a very very different way. Right, quantum 0:08:31.680 --> 0:08:34.760 mechanical randomness, as we'll dig into, it's not arbitrary or 0:08:34.840 --> 0:08:37.480 at the whims of some god. Right, how do you know, Daniel? 0:08:37.600 --> 0:08:39.000 You know, we might be at the whims of the 0:08:39.040 --> 0:08:42.400 writers of the simulation. But whatever code they wrote is 0:08:42.440 --> 0:08:45.240 what determines how the universe seems to work. What if 0:08:45.280 --> 0:08:47.600 that code is at the whim of some other writers. Well, 0:08:47.600 --> 0:08:49.160 maybe it is, but they don't seem to have been 0:08:49.280 --> 0:08:52.400 changing the code recently. It seems like the code is 0:08:52.440 --> 0:08:55.800 pretty stable over the fourteen billion years at the universe's history, 0:08:56.080 --> 0:08:58.200 So there haven't been any updates. Well, it seems like 0:08:58.200 --> 0:08:59.920 we've done a double take here on the random of 0:09:00.240 --> 0:09:03.400 the universe. And the latest is that according to quantum mechanics, 0:09:03.920 --> 0:09:07.440 things are random. But is that really true? And so 0:09:07.559 --> 0:09:09.520 to be on the podcast we'll be tackling the question 0:09:14.600 --> 0:09:18.839 how do we know quantum mechanics is really random as 0:09:18.840 --> 0:09:22.360 opposed to just plane wacky or flaky or at the 0:09:22.360 --> 0:09:26.560 whim of some quantum mechanical gods. Well, you know, quantum 0:09:26.559 --> 0:09:29.600 mechanics has probabilities in it, and you can talk about 0:09:29.640 --> 0:09:34.760 what probabilities means. Sometimes probability just means our lack of information. 0:09:34.920 --> 0:09:37.600 Things we don't know, but in principle could predict. And 0:09:37.679 --> 0:09:42.319 sometimes probability means fundamentally random, governed by our process outside 0:09:42.320 --> 0:09:44.679 of our control. You're gonna bet on the outcome of 0:09:44.679 --> 0:09:47.760 a Roulette wheel spin, for example, you might think that's random, 0:09:47.840 --> 0:09:50.240 and in principle, if you knew how the ball bounced 0:09:50.440 --> 0:09:52.680 and you spun it the same way twice, you should 0:09:52.720 --> 0:09:55.679 get exactly the same answer, So it's not really random. 0:09:55.920 --> 0:09:59.199 The probabilities, they're just come from your lack of understanding. 0:09:59.320 --> 0:10:02.000 The question really is quantum mechanics the same way. Are 0:10:02.040 --> 0:10:06.439 there details which actually do determine the outcome of these experiments, 0:10:06.440 --> 0:10:08.840 which is not aware of them? Or is the universe 0:10:08.920 --> 0:10:12.520 really actually at its core a random number generator? You're 0:10:12.559 --> 0:10:15.600 asking is it really random or does it just seem random? 0:10:15.640 --> 0:10:17.800 Because something can seem random, right like I can have 0:10:17.880 --> 0:10:21.199 a computer code that spits out random numbers, which will 0:10:21.200 --> 0:10:24.040 look pretty random to anyone, but actually there's sort of 0:10:24.200 --> 0:10:27.760 card coded on the computer right exactly. Random number generators 0:10:27.760 --> 0:10:31.080 follow a sequence where computers follow rules. They can't actually 0:10:31.160 --> 0:10:34.920 generate random numbers. They can only have pseudo random number 0:10:35.000 --> 0:10:38.120 sequences that sort of look random ish, right, And so 0:10:38.160 --> 0:10:41.120 we're asking the same question about the entire universe. Is 0:10:41.160 --> 0:10:44.200 the universe actually random at its core? Or does it 0:10:44.320 --> 0:10:46.240 just seem random? And I guess we need to go 0:10:46.280 --> 0:10:48.679 to quantum mechanics to find the answer. And we've been 0:10:48.679 --> 0:10:51.839 talking around this topic and a few recent episodes and 0:10:52.000 --> 0:10:55.080 listeners have responded and asked us to dig into the 0:10:55.120 --> 0:10:57.240 heart of the matter. Yeah, and as usually, we were 0:10:57.240 --> 0:10:59.560 wondering how many people out there I thought about whether 0:10:59.679 --> 0:11:02.520 quantum mechanics really is random or not. So thanks to 0:11:02.520 --> 0:11:04.960 everybody who answers these questions for us. It gives us 0:11:05.000 --> 0:11:07.000 a great sense for what people know and what they're 0:11:07.000 --> 0:11:09.800 wondering about, and what you might be thinking out there. 0:11:10.080 --> 0:11:12.040 And if you would like to lend your voice for 0:11:12.040 --> 0:11:14.600 a future episode, please don't be shy, all right to 0:11:14.720 --> 0:11:17.640 us two questions at Daniel and Jorge dot com. So 0:11:17.720 --> 0:11:20.280 think about it for a second. Do you think quantum 0:11:20.320 --> 0:11:24.120 mechanics really is random? Here's what people had to say. Actually, 0:11:24.160 --> 0:11:26.760 I then that's what Einstein thought. He thought there was 0:11:26.760 --> 0:11:30.200 some hidden variables are controlled all the processes, and we 0:11:30.240 --> 0:11:32.439 didn't know about that, and that's why we thought it 0:11:32.559 --> 0:11:36.360 rest them, but I think there have been many experiments 0:11:36.400 --> 0:11:38.679 where they redeed the same thing over in our work, 0:11:38.760 --> 0:11:42.400 but in the same conditions, but there's a different result 0:11:42.520 --> 0:11:45.200 each time, and that's what that's how we know that 0:11:45.840 --> 0:11:48.920 it is truly random is such a question. We do 0:11:49.000 --> 0:11:53.080 experiments thousands and thousands of times so that we can 0:11:53.200 --> 0:11:57.480 get probability curves that show randomness. But he would only 0:11:57.480 --> 0:12:00.280 know to a certain amount of certainty based on how 0:12:00.280 --> 0:12:03.880 many experiments you do, and you can't do an infinite 0:12:03.960 --> 0:12:06.240 number of experiments. So maybe we don't know that it's random, 0:12:06.320 --> 0:12:10.240 but it's just random enough for purposes. Well, if it's 0:12:10.440 --> 0:12:13.080 not random, I guess scientists would have figured out how 0:12:13.120 --> 0:12:15.760 it's really working, and we would have really cool quantum 0:12:15.760 --> 0:12:19.600 computers by now. We may not know it as an 0:12:19.679 --> 0:12:24.959 absolute fact, but our models really suggest it is random 0:12:25.160 --> 0:12:30.240 through many experiments and theories. That model of randomness holds 0:12:30.240 --> 0:12:33.400 out really, really well. And that's about as good as 0:12:33.400 --> 0:12:37.160 we can get if the model fits we accepted. I'm 0:12:37.200 --> 0:12:39.040 a big fan of the idea that there's a hidden 0:12:39.120 --> 0:12:41.480 variable that we don't understand, But at the same time 0:12:41.640 --> 0:12:44.600 I realized that all the evidence says that it's really 0:12:44.640 --> 0:12:48.880 really random. There's that whole thing where you send electrons 0:12:49.040 --> 0:12:53.520 through a slit experiment, one electron at a time, and 0:12:53.559 --> 0:12:57.040 they still interfere because, as I've heard you guys say, 0:12:57.040 --> 0:12:59.520 it's a field, not a point. But I don't really 0:12:59.600 --> 0:13:03.840 understand damn that um. As a computer programmer, I know 0:13:03.960 --> 0:13:07.800 that quantum is the gold standard for truly random numbers, 0:13:08.000 --> 0:13:09.959 but I guess I really don't understand that at all. 0:13:10.240 --> 0:13:13.000 If you set up an experiment, well so they call 0:13:13.040 --> 0:13:16.360 it an ensemble, if you set up multiple instances of 0:13:16.400 --> 0:13:21.120 that experiment and everything is the same, and you produce 0:13:21.160 --> 0:13:23.120 the electron, say you, I don't know if I were 0:13:23.120 --> 0:13:26.240 it in a given direction, And then well, since you 0:13:26.400 --> 0:13:30.160 know its position or the trajectory it's taking, if you 0:13:30.280 --> 0:13:34.720 then try to measure its momentum while it's moving, even 0:13:34.760 --> 0:13:37.240 though the experiments are set up in exactly the same way, 0:13:37.559 --> 0:13:40.880 you get different answers for the momentum, and it doesn't 0:13:40.880 --> 0:13:43.240 depend on how you've set up the experiment, because the 0:13:43.360 --> 0:13:47.160 ensembles are exactly the same and there is no like 0:13:47.280 --> 0:13:50.680 sort of external factor that you can change that somehow 0:13:50.760 --> 0:13:54.920 correlates with the measured momentum and that's why we say 0:13:55.000 --> 0:13:58.400 quantum mechanics is random. Well, I guess you could set 0:13:58.480 --> 0:14:01.360 up the same experiment many many times and if you 0:14:01.400 --> 0:14:05.640 get different outcomes um with the sort of random distribution, 0:14:06.120 --> 0:14:10.720 you would know that it's very random. Otherwise I have 0:14:10.760 --> 0:14:14.040 no idea. Interesting, I feel like some people don't want 0:14:14.040 --> 0:14:16.920 to know, kind of. It is really hard to accept 0:14:16.960 --> 0:14:19.720 this idea that the universe is so different from the 0:14:19.720 --> 0:14:23.080 one you experience. So I think a lot of people resisted. Yeah, 0:14:23.160 --> 0:14:27.080 and do you think quantum mechanics is random or maybe 0:14:27.080 --> 0:14:30.280 it was just discovered randomly? It does seem like the 0:14:30.360 --> 0:14:33.480 history of science is a little bit random, you know, 0:14:33.680 --> 0:14:36.520 especially in the case of quantum mechanics, because we had 0:14:36.560 --> 0:14:39.600 a few experiments that people had done and nobody really understood, 0:14:39.800 --> 0:14:41.920 and then Einstein and Plank came along and sort of 0:14:41.920 --> 0:14:44.800 put the pieces together years later. Makes you wonder if 0:14:44.800 --> 0:14:46.920 it could have happened sooner, or maybe if it could 0:14:46.960 --> 0:14:50.040 have happened decades later. It's fun to think about alternative 0:14:50.120 --> 0:14:53.000 histories and what we might have discovered or not at all. Right, 0:14:53.080 --> 0:14:55.640 Like what if Einstein had decided that he wanted to 0:14:55.680 --> 0:14:58.960 play soccer for a living. Maybe we wouldn't be having 0:14:58.960 --> 0:15:02.040 this conversation at all. Usually can't say that about historical figures, 0:15:02.080 --> 0:15:03.760 but Eisen is one of those figures where if he 0:15:03.800 --> 0:15:05.760 hadn't come along at the moment he did, things would 0:15:05.760 --> 0:15:08.520 be super different. Things might be different. There are people 0:15:08.560 --> 0:15:10.760 who say that a lot of the precursors to his 0:15:10.920 --> 0:15:13.200 ideas came from other people, and so it was sort 0:15:13.240 --> 0:15:15.640 of inevitable for them to click together. You know, a 0:15:15.680 --> 0:15:18.560 lot of the math that underpins relativity was developed by 0:15:18.600 --> 0:15:22.320 other folks. Rimon, for example, developed the rimanny and manifold, 0:15:22.560 --> 0:15:25.440 which Einstein realized was a great way to describe the 0:15:25.480 --> 0:15:28.720 curvature of space. Other folks were working on similar ideas 0:15:28.760 --> 0:15:31.200 and may have brought it together even without Einstein, though 0:15:31.320 --> 0:15:34.640 it could have taken a few years or decades longer. Well, 0:15:34.720 --> 0:15:37.240 Eisen did what he did. And here we are talking 0:15:37.280 --> 0:15:40.760 about quantum mechanics and randomness and whether or not it 0:15:40.840 --> 0:15:43.920 is actually random at its core. And so I guess, Daniel, 0:15:43.960 --> 0:15:46.360 let's start with the basics here. Uh, Well, first of all, 0:15:46.400 --> 0:15:48.400 what do we mean by the word random? So by 0:15:48.440 --> 0:15:51.400 random we really mean something which is not determined by 0:15:51.440 --> 0:15:54.880 the experimental setup you'd build an experiment to shoot a ball, 0:15:55.120 --> 0:15:57.240 or to flip a coin, or to roll a dice 0:15:57.320 --> 0:16:00.280 or whatever. If it really is random, then you can 0:16:00.280 --> 0:16:04.400 do the same experiment twice and get different outcomes, right 0:16:04.440 --> 0:16:07.560 Like For example, a computer random number generator is not 0:16:07.680 --> 0:16:10.640 really random because it uses a computer formula, right like that. 0:16:10.680 --> 0:16:13.520 One works by taking a look at the current time, 0:16:13.880 --> 0:16:16.440 grabbing a bunch of different variables that are changing all 0:16:16.480 --> 0:16:19.080 the time, and then it processes those and then it 0:16:19.160 --> 0:16:21.600 spits out what seems like a random number, but it's 0:16:21.640 --> 0:16:24.120 not really random because venia what all the numbers that 0:16:24.160 --> 0:16:26.640 went into the random number generator, you could generate the 0:16:26.680 --> 0:16:28.720 exact same sequence, right yeah, and we do that all 0:16:28.760 --> 0:16:31.200 the time. You have a random number seeds for example. 0:16:31.520 --> 0:16:34.240 These are the parameters that control the random number generation. 0:16:34.280 --> 0:16:36.280 And if you give a computer the same seeds, it 0:16:36.320 --> 0:16:39.400 will generate the same sequence of random numbers every time. 0:16:39.840 --> 0:16:43.640 So computer random number generators are deterministic. They can be 0:16:43.680 --> 0:16:47.240 predicted from their inputs and reproduced. You run the same 0:16:47.320 --> 0:16:50.120 random number generator with the same inputs get exactly the 0:16:50.200 --> 0:16:53.760 same outputs, So that's deterministic. That's not random, But they 0:16:53.800 --> 0:16:57.760 are chaotic. They are hard to predict. Their designed to 0:16:57.800 --> 0:17:00.720 be complicated the way. For example, a die is designed 0:17:00.880 --> 0:17:04.320 to be unpredictable, as all these sharp edges which bounce 0:17:04.400 --> 0:17:07.719 unpredictably against surfaces and makes it really tricky to know 0:17:07.760 --> 0:17:10.439 if a two or four is going to land upright, 0:17:10.440 --> 0:17:14.200 It's very sensitive to exactly how you throw it, which 0:17:14.200 --> 0:17:17.240 makes it hard to predict and appear random but not 0:17:17.320 --> 0:17:20.920 actually be random, right, because a die with sharp edges 0:17:20.960 --> 0:17:23.040 sort of like if you stand it on one corner, 0:17:23.080 --> 0:17:24.879 I guess it might fall to the rider, It might 0:17:24.920 --> 0:17:26.760 fault to the left, or it might bounce to the 0:17:26.840 --> 0:17:28.640 right or left, just like a coin if you stand 0:17:28.640 --> 0:17:31.240 it up on its side, it could maybe um flip 0:17:31.359 --> 0:17:34.480 or land and either way. Yeah, imagine trying to learn, 0:17:34.520 --> 0:17:36.720 for example, how to flip a coin so that it 0:17:36.800 --> 0:17:40.080 always comes up heads. In principle, you could you could 0:17:40.119 --> 0:17:42.520 learn how to spin it at just the right frequency 0:17:42.600 --> 0:17:44.680 and toss it in the air just the right velocity, 0:17:44.760 --> 0:17:46.720 so it has a certain number of flips before it 0:17:46.840 --> 0:17:48.920 lands on your hand and it's always going to come 0:17:48.960 --> 0:17:51.119 up heads. That would be a great skill, right, But 0:17:51.320 --> 0:17:54.159 it's so hard to do because it's so sensitive to 0:17:54.200 --> 0:17:56.800 all of those details. You'd have to be a master 0:17:56.920 --> 0:17:59.320 coin flipper to be able to do that same with 0:17:59.359 --> 0:18:01.680 a dive. Some many knew how to roll sevens every 0:18:01.680 --> 0:18:05.200 single time. They would make zillions of dollars at casinos 0:18:05.320 --> 0:18:07.800 every day. Right, The whole game of craps is built 0:18:07.840 --> 0:18:10.679 on the assumption that nobody can really control what happens 0:18:10.680 --> 0:18:12.280 to the diet even though they give them to you, 0:18:12.320 --> 0:18:14.880 they let you roll them, right, And so the whole 0:18:14.880 --> 0:18:18.520 assumption there is that you can't reproduce the same toss 0:18:18.560 --> 0:18:20.840 over and over again. So I don't let you into 0:18:20.920 --> 0:18:23.200 casinos anymore. It may they stop you at the door first, 0:18:23.240 --> 0:18:26.560 they're like, are you Antonian physicists or a quantum mechanicis 0:18:26.720 --> 0:18:29.400 may say quantum physicists. They'll let you in. They'll let 0:18:29.440 --> 0:18:31.919 you in exactly because you've given up. You've allowed the 0:18:32.000 --> 0:18:34.280 randomness to enter your life, all right. So that's the 0:18:34.359 --> 0:18:37.240 kind of the difference between random and not random. Random 0:18:37.359 --> 0:18:41.480 you can't predict given the initial conditions, and not random 0:18:41.600 --> 0:18:43.480 you can't predict it even if it is really hard. 0:18:43.600 --> 0:18:45.800 If you can't predict it, then it's possible that you 0:18:45.800 --> 0:18:48.200 can't predict it, and so it's not random, and everything 0:18:48.240 --> 0:18:52.199 in your everyday experience is not random. Whether you hit 0:18:52.200 --> 0:18:54.840 a green light, or whether you trip on the steps, 0:18:55.080 --> 0:18:57.760 or whether that bird poops on your shoulder or whatever. 0:18:58.000 --> 0:19:01.320 These things can seem random, whether really just complex. They're 0:19:01.320 --> 0:19:04.280 actually just chaotic. Even the weather, right, the weather is 0:19:04.320 --> 0:19:08.400 not fundamentally quantum mechanically random. It's just difficult to predict 0:19:08.400 --> 0:19:11.439 because it's so complicated. So in our experience, everything that 0:19:11.520 --> 0:19:15.639 seems random is actually just deterministic and complicated, or at 0:19:15.680 --> 0:19:19.320 least I think you mean, it's mostly deterministic and chaotic, right, 0:19:19.480 --> 0:19:22.840 And it's it's just saying that Newtonian dynamics dominate our 0:19:22.880 --> 0:19:24.919 everyday lives. But there is still a little bit of 0:19:24.920 --> 0:19:27.880 a quantum at it's hard right at the microscopic level, 0:19:28.200 --> 0:19:31.439 right like as the coin hits the table, there is 0:19:31.440 --> 0:19:34.160 some sort of maybe quantum interaction there. They could determine 0:19:34.160 --> 0:19:36.280 whether it flips to the right or to the left. Well, 0:19:36.280 --> 0:19:39.880 we do know that microscopically everything we experience is made 0:19:39.880 --> 0:19:42.840 of quantum objects, and so if quantum mechanics is random, 0:19:42.880 --> 0:19:45.119 then you know, you might ask why aren't things made 0:19:45.200 --> 0:19:48.320 of quantum objects also random. The answer is that that 0:19:48.440 --> 0:19:52.240 randomness mostly averages out, and so even electron is going 0:19:52.280 --> 0:19:54.919 to like quantum mechanically fluctuate to the left somewhere than 0:19:54.960 --> 0:19:57.639 an electron quantum mechanically fluctuating to the right. So when 0:19:57.680 --> 0:20:00.920 you have in big enough groups of quantum objects, these 0:20:00.920 --> 0:20:03.920 things tend to wash out. It's very difficult to actually 0:20:04.000 --> 0:20:11.040 pinpoint quantum mechanical impacts on everyday macroscopic classical objects. Otherwise 0:20:11.080 --> 0:20:13.040 we would have discovered quantum mechanics sooner. You know, it 0:20:13.040 --> 0:20:15.600 would have been more obvious if there were quantum mechanical 0:20:15.640 --> 0:20:17.880 impacts on our everyday life. Right, But you just found 0:20:17.920 --> 0:20:19.720 it a little bit absolute in But then you said 0:20:19.760 --> 0:20:23.520 you mostly wash this out, right, not completely right. There 0:20:23.560 --> 0:20:25.639 is still a little bit of tiny, little bit of 0:20:25.680 --> 0:20:28.720 maybe quantum randomness in our everyday lives too. Yeah, there's 0:20:28.720 --> 0:20:30.679 a little bit there. Right In the end, these things 0:20:30.720 --> 0:20:33.919 are averages, so there are probabilities you could in principle 0:20:34.359 --> 0:20:37.760 disappear and quantum tunnel to the other side of your house. Right, 0:20:37.760 --> 0:20:41.680 It's not impossible. That's why you should never say things absolutely. Also, 0:20:41.760 --> 0:20:45.520 this is not something that we a hundred understand, right, 0:20:45.600 --> 0:20:47.960 How do quantum mechanical objects when they're all tiny, the 0:20:48.040 --> 0:20:50.719 huge frothing mass of them, how did they come together 0:20:50.760 --> 0:20:54.160