WEBVTT 00:00:16.331 --> 00:00:18.430 Thank you, it's a pleasure to be here. 00:00:18.430 --> 00:00:20.630 They asked me if I wanted a drink before I came on 00:00:20.630 --> 00:00:23.010 and I asked for a pint but they gave me water. 00:00:23.010 --> 00:00:24.843 (Laughter) 00:00:24.843 --> 00:00:27.192 So, following the other speakers I have a change of pace, 00:00:27.192 --> 00:00:29.212 a little bit of a fun talk. 00:00:29.212 --> 00:00:32.877 And what I am going try and do is convince you you're a stimulation, 00:00:32.887 --> 00:00:35.285 and that physics can prove it, okay? 00:00:35.285 --> 00:00:36.369 (Laughter) 00:00:36.369 --> 00:00:39.674 So, instead of a usual uplifting talk, this is a different kind of talk. 00:00:39.914 --> 00:00:43.190 Okay, so, there's one thing you know for certain, 00:00:43.190 --> 00:00:46.119 that is that you exist as a flesh and blood human being; 00:00:46.119 --> 00:00:48.896 my goal is to convince you otherwise. Okay? 00:00:50.156 --> 00:00:52.416 So, logic is not going to be enough, 00:00:52.426 --> 00:00:55.328 you guys are going to be simulation deniers, 00:00:56.272 --> 00:00:58.291 there's just no way round it. 00:00:58.291 --> 00:01:01.923 So, my actual goal will be to actually create a sliver of doubt in your minds, 00:01:01.933 --> 00:01:05.749 so that you actually think about this, and what it might mean. Okay? 00:01:06.739 --> 00:01:09.069 So, here's is the first check about simulations. 00:01:09.761 --> 00:01:11.729 How many of you have ever played a computer game? 00:01:11.748 --> 00:01:13.288 Just raise your hands. 00:01:13.288 --> 00:01:14.612 Ah, alright. 00:01:14.612 --> 00:01:18.570 So, did you do it against simulated player or simulated players? 00:01:18.607 --> 00:01:22.667 Or, in fact, was it you, several people plus simulated people? 00:01:23.482 --> 00:01:27.408 Right. And what role did you take? Was it a pawn or a hero? 00:01:27.458 --> 00:01:30.545 What role do you have in life? Is it pawn or hero? 00:01:30.545 --> 00:01:33.314 Right. Are you the king, for example? 00:01:33.324 --> 00:01:34.217 (Laughter) 00:01:34.220 --> 00:01:36.588 I don't see him here... but... 00:01:38.542 --> 00:01:41.111 Now, the other thing you might ask, if you were a social scientist, 00:01:41.131 --> 00:01:43.105 or other kind of scientist like a cosmologist: 00:01:43.115 --> 00:01:45.607 Would you like to run realistic simulations 00:01:45.636 --> 00:01:48.876 to test and develop your theories? Likewise for political candidates. 00:01:48.937 --> 00:01:52.622 Right? So, I'm just trying to see there's motivation for it. 00:01:52.653 --> 00:01:56.574 And then the question is: Are computation and simulation capabilities 00:01:57.709 --> 00:01:59.498 increasing over time? 00:01:59.498 --> 00:02:02.337 So, think of the HetNOS, think about Moore's law, 00:02:02.337 --> 00:02:04.700 think about what computer you had when you were young 00:02:04.700 --> 00:02:07.282 and what you have on you now, not that you're not all young still. 00:02:07.282 --> 00:02:09.912 Okay, that's just setting you up for having the doubt. 00:02:10.933 --> 00:02:14.448 Okay, so we'll take a little journey into philosophy. 00:02:14.448 --> 00:02:19.213 Solipsism is the idea that one's own mind is the only thing that's sure to exist. 00:02:19.213 --> 00:02:22.522 It turns out, people have been studying this for decades, 00:02:22.522 --> 00:02:27.366 and realizes both irrefutable and indefensible at the same time, 00:02:27.372 --> 00:02:29.734 so have this point of view, 00:02:29.734 --> 00:02:32.548 and that it's not a falsifiable hypothesis, 00:02:32.548 --> 00:02:34.962 there are people who work on this issue. 00:02:34.962 --> 00:02:38.300 So, there doesn't seem to be any imaginable disproof that you can have, 00:02:38.300 --> 00:02:40.692 so even if you have a Solipsan, he dies, 00:02:40.692 --> 00:02:44.098 you can't falsify his belief, because he's not there to do it. 00:02:44.098 --> 00:02:47.694 This is a pragmatic dead end, it's kind of like what we have on TV now, 00:02:47.694 --> 00:02:51.568 which is, you know, zombie philosophy. 00:02:52.524 --> 00:02:56.986 But there is an opposite, that is philosophical zombies. 00:02:57.036 --> 00:02:59.748 There's a slight use to philosophical zombies. 00:02:59.818 --> 00:03:02.016 So what is the idea here? 00:03:02.016 --> 00:03:04.444 The philosophical zombie is a hypothetical being 00:03:04.466 --> 00:03:07.346 that in this thing what you all thought a normal human being, 00:03:07.389 --> 00:03:10.317 that is everybody you think you are, you know what you think you are, 00:03:10.317 --> 00:03:14.633 except that it lacks conscious experience, qualia or sentience. 00:03:14.633 --> 00:03:18.650 So, if you take a philosophical zombie and poke it with a sharp object, 00:03:18.690 --> 00:03:22.951 it doesn't feel any pain, however, it behaves exactly as if it does. 00:03:22.951 --> 00:03:26.103 It would say "ouch" and do all the usual kind of things. 00:03:26.103 --> 00:03:30.536 So, what the zombie is there for, is to support the idea 00:03:30.536 --> 00:03:34.237 that the world includes two kinds of things: the mental and the physical, 00:03:34.238 --> 00:03:38.062 or the concepts and the physical world around you. 00:03:38.097 --> 00:03:40.313 And so that's the idea. 00:03:40.583 --> 00:03:44.226 So, we have in cosmology, lots of things. We have the anthropic principal, 00:03:44.226 --> 00:03:47.469 that is, a philosophical concept that the universe must be compatible 00:03:47.492 --> 00:03:49.378 with conscious life that observes it. 00:03:49.378 --> 00:03:51.867 And there's a strong version and a weak version. 00:03:51.867 --> 00:03:55.658 One of them that says the universe is compelled to have conscious life emerge, 00:03:55.658 --> 00:04:00.319 and the other says that the universe is fine-tuned for life to be necessary. 00:04:00.319 --> 00:04:05.850 And this is pretty much in line with a lot of even more specific kind of ideas, 00:04:05.850 --> 00:04:11.021 from conservative Christianity and Islam, that there's intelligent design, 00:04:11.037 --> 00:04:14.867 or that there could be like a simulation. I'm working on you... so.... 00:04:16.647 --> 00:04:19.306 And we also have the idea of multiverses, 00:04:19.306 --> 00:04:21.985 that there are many different kinds... there's a metauniverse 00:04:21.985 --> 00:04:24.727 and there's many possible universes inside of it. 00:04:24.727 --> 00:04:27.612 And there are different reasons for that, quantum mechanics, 00:04:27.612 --> 00:04:30.892 but also a way to explain whether physical constants happen to be the ones 00:04:30.892 --> 00:04:33.702 that make this auditorium possible. 00:04:33.877 --> 00:04:38.094 And so, you know, one way is to have that many real universes, 00:04:38.122 --> 00:04:40.514 the other way is just to make a lot of simulations. 00:04:40.514 --> 00:04:43.224 So, your choice. Okay, so now we move on. 00:04:43.254 --> 00:04:45.753 Here's the crux of the arguments, 00:04:45.753 --> 00:04:49.043 and these arguments have been around for more than 30 years, 00:04:49.043 --> 00:04:52.222 they were first published 30 years ago, 00:04:52.612 --> 00:04:55.486 and what people went to a lot of trouble to show, 00:04:55.506 --> 00:04:58.432 that one of these three things is extremely likely to be true. 00:04:58.442 --> 00:05:01.350 So, you get your choice between No. 1, No. 2 and No. 3, 00:05:01.350 --> 00:05:04.295 just like the doors, look what's behind each door. 00:05:04.295 --> 00:05:07.337 The first one is: Human civilization is unlikely 00:05:07.337 --> 00:05:09.858 to reach a level of technological maturity 00:05:09.858 --> 00:05:13.746 capable of producing simulated realities, or it's physically impossible. 00:05:13.746 --> 00:05:17.109 Okay, so we made some progress in 30 years and I'll mention that. 00:05:17.123 --> 00:05:21.173 The second is: Comparable civilizations throughout the universe 00:05:21.975 --> 00:05:24.611 which do reach that capability 00:05:24.619 --> 00:05:27.864 will choose not to make simulations 00:05:27.864 --> 00:05:32.446 in such a large scale that, in fact, the probability of being a simulated being 00:05:32.446 --> 00:05:34.870 is much higher than probability of being a real being. 00:05:34.870 --> 00:05:38.165 So, those are your choices, right -- 00:05:39.171 --> 00:05:41.756 there's some other choices, but they're extraordinarily unlikely, 00:05:41.756 --> 00:05:44.036 and we can pretty much rule them out. 00:05:44.036 --> 00:05:47.567 And the 3rd choice is: Any entities with our general set of experiences 00:05:47.587 --> 00:05:50.421 are almost certainly to be living in a simulation. 00:05:50.421 --> 00:05:54.593 That would be us. Right? Okay? In case you guys aren't paying attention. 00:05:54.593 --> 00:05:56.053 (Chuckles) 00:05:56.053 --> 00:05:59.995 Okay. So, let's talk about making simulator realities by humans. 00:06:00.938 --> 00:06:03.147 So, will humans produce realistic simulations? 00:06:03.147 --> 00:06:05.353 And the answer is yes. 00:06:05.353 --> 00:06:07.865 I have to keep coming back because I just wrote this talk 00:06:07.891 --> 00:06:10.458 and so I don't remember what I have to say. 00:06:10.458 --> 00:06:15.433 And, so, the answer to that is clearly yes, you guys already proved it, 00:06:15.449 --> 00:06:18.642 because there's a lot of money to be made in making computer games, 00:06:18.642 --> 00:06:20.669 simulated realities. 00:06:20.669 --> 00:06:23.535 And the better the simulator reality, the more people you get involved in it. 00:06:23.535 --> 00:06:26.907 There's a lot of entertainment, we have a lot of animated movies. 00:06:26.907 --> 00:06:29.450 Now, we're going to have animated interactive movies 00:06:29.450 --> 00:06:32.028 and videos and pornography. 00:06:32.031 --> 00:06:34.843 So, you know, you can't rule out pornography, 00:06:34.843 --> 00:06:39.094 in the early days of the Internet, pornography was the No. 1 commerce, 00:06:39.431 --> 00:06:42.394 it was roughly half the commerce in the Internet in the early days. 00:06:42.402 --> 00:06:46.785 And even today, 50% of the bits that are transmitted on the Internet 00:06:46.811 --> 00:06:48.858 are transmitted for porn. 00:06:49.348 --> 00:06:51.635 So, you can wonder: Why is it? Well, originally stories 00:06:51.635 --> 00:06:54.188 and then there got to be pictures, and then there got to be videos, 00:06:54.188 --> 00:06:56.031 pretty soon there'll be interactive videos. 00:06:56.031 --> 00:06:59.457 So, it's clear there is a tremendous financial motivation, 00:06:59.457 --> 00:07:01.227 and especially here in Media City, 00:07:01.227 --> 00:07:03.755 where people make their living out of these kind of things. 00:07:03.755 --> 00:07:07.717 So, how... I'm not sure which of the three, But OK. 00:07:09.723 --> 00:07:12.914 How detailed and how accurate will the simulations be? 00:07:12.914 --> 00:07:15.708 And the answer turns out, as we know from experience, 00:07:15.708 --> 00:07:17.829 computation power is the first issue, 00:07:17.829 --> 00:07:19.947 you have to have tremendously good computation power 00:07:19.947 --> 00:07:22.132 to make a really good quality simulation, 00:07:22.132 --> 00:07:24.674 and good programming, that is good software, 00:07:24.674 --> 00:07:26.816 to explain what's going on, that's the second. 00:07:26.816 --> 00:07:31.740 But, clearly we're making progress, just look at the games, look at PONG, 00:07:31.742 --> 00:07:36.344 and look at that the kind of video games we have now. So, we'll see. 00:07:36.576 --> 00:07:39.236 What about simulations by other civilizations? 00:07:39.236 --> 00:07:42.798 So, now we know a lot more about this than we did 30 years ago. 00:07:42.798 --> 00:07:44.564 We've made tremendous progress. 00:07:44.564 --> 00:07:47.656 We've discovered more than 2,000 other stars 00:07:47.656 --> 00:07:49.998 that have planetary systems around them. 00:07:49.998 --> 00:07:54.863 And we know there is at least on the order of a billion or more habitable planets 00:07:54.869 --> 00:07:57.914 in our galaxy, and there's about a 100 billion galaxies 00:07:57.914 --> 00:08:01.954 for around 10^20 to 10^22 depending what your range 00:08:01.954 --> 00:08:06.619 possible sites for life and then advanced civilizations in the universe. 00:08:06.619 --> 00:08:10.214 So, what are the chances that the earth is the most advanced, 00:08:10.214 --> 00:08:12.524 the most computationally powerful. 00:08:12.932 --> 00:08:17.977 Well, the odds, you got to be really, pretty much thinking you're special, 00:08:17.988 --> 00:08:20.847 to think that the odds are that we're the top. 00:08:25.329 --> 00:08:31.479 So, the question is: Will advanced beings run simulations? 00:08:32.241 --> 00:08:35.034 And, in fact, will simulated beings run simulations? 00:08:35.034 --> 00:08:38.671 If we're simulated, are we running simulations in our simulations, 00:08:38.671 --> 00:08:42.757 simulations all the way down? If you know the things. 00:08:42.757 --> 00:08:49.393 So, even the people running our simulation don't know if they're a simulation or not. 00:08:50.333 --> 00:08:54.095 It's interesting, because it creates ethics and a bunch of things 00:08:54.095 --> 00:08:57.290 because there might be somebody watching you. 00:08:57.349 --> 00:09:01.585 So, are ethical considerations likely to stop every single civilization 00:09:01.585 --> 00:09:05.513 from running simulations and running large numbers of simulations? 00:09:05.513 --> 00:09:08.269 Well, the answer I think is "no". 00:09:08.269 --> 00:09:11.740 What if doing simulations is likely to say what we think are real lives? 00:09:11.740 --> 00:09:13.837 Right? We're willing to do the simulations 00:09:13.838 --> 00:09:16.568 even though they're being strapped in that simulation, right? 00:09:16.568 --> 00:09:17.852 Conscious beings. 00:09:17.852 --> 00:09:20.700 And the other thing you might consider is how do human beings 00:09:20.700 --> 00:09:23.178 treat what they think are real human beings. 00:09:23.178 --> 00:09:26.278 How's the ethical treatment on our Earth? 00:09:26.278 --> 00:09:28.410 And how much more is society likely to advance 00:09:28.410 --> 00:09:31.522 before we're doing 00:09:31.522 --> 00:09:35.578 very advanced simulations of civilizations and beings? 00:09:36.569 --> 00:09:40.924 So, we'll probably all be in a simulation. The lights are not on enough in here, 00:09:40.924 --> 00:09:42.954 but look to the left and look to the right, 00:09:42.954 --> 00:09:46.482 if there's anybody here you think is a real person, this is a random sample, 00:09:46.482 --> 00:09:49.470 then you're probably not. (Laughter) 00:09:50.818 --> 00:09:53.588 But, you know, If you think you're a social scientist 00:09:53.588 --> 00:09:56.009 or an anthropologist or something, and you want to run 00:09:56.009 --> 00:09:58.180 and see how the civilizations rise and fall, 00:09:58.180 --> 00:10:01.566 you'll run simulations with up to billions of people. 00:10:02.771 --> 00:10:04.527 And you will run many of those simulations, 00:10:04.527 --> 00:10:07.318 so it's not so hard to imagine you'll get up to the level 00:10:07.318 --> 00:10:11.641 of 10^12:1 simulated beings to unsimulated beings, 00:10:12.086 --> 00:10:14.814 that's why the probability becomes fairly likely 00:10:14.814 --> 00:10:19.585 that any being that has a behavior or activities and experiences like us 00:10:19.588 --> 00:10:21.121 is simulated. 00:10:22.616 --> 00:10:26.372 Sorry, I got some sunscreen in my eye. 00:10:26.372 --> 00:10:29.446 Put on sunscreen this morning in case it was an unusual day in England. 00:10:29.446 --> 00:10:32.113 (Laughter) 00:10:32.113 --> 00:10:33.987 And I got a little in my eye here. 00:10:34.396 --> 00:10:38.603 So let's talk about how we're going to do the simulations on the Earth. 00:10:39.990 --> 00:10:42.021 This is part of going back to convince you 00:10:42.021 --> 00:10:43.993 that we're going to have realistic simulations 00:10:43.993 --> 00:10:46.962 and we're going to have artificial reality to go with it. 00:10:47.391 --> 00:10:50.806 So, can we take a real brain and make it into a virtual mind? 00:10:50.806 --> 00:10:54.229 And the answer is: So, here is the purple real brain, 00:10:54.229 --> 00:10:57.233 and the neurons behind it, it's this neural net, 00:10:57.233 --> 00:11:00.118 it's the regional neural net, as far as we're concerned. 00:11:00.118 --> 00:11:03.829 And then on the left, yeah your left, 00:11:03.829 --> 00:11:06.191 there is the beginnings of a mapping of a brain, 00:11:07.033 --> 00:11:10.230 so that I can take and map that brain, and just place it into a computer. 00:11:11.017 --> 00:11:12.591 So, how's that going to work? 00:11:12.591 --> 00:11:15.610 The answer is, it's going to work just fine, 00:11:15.610 --> 00:11:18.238 because we're there to the point where we can do it now. 00:11:18.238 --> 00:11:22.537 So, here is a high-resolution, 45-minute brain scan 00:11:22.537 --> 00:11:24.589 that was done in February. 00:11:24.589 --> 00:11:28.673 And 45 minutes, that's how long you have to hold the person's head still, 00:11:28.673 --> 00:11:31.170 in order to make a map to this level. 00:11:31.170 --> 00:11:33.358 And what you can see here are the main -- 00:11:33.358 --> 00:11:35.838 Let's see if the laser pointer works -- -- No -- 00:11:35.838 --> 00:11:39.069 So, you can see here the main highways in your brain. 00:11:39.069 --> 00:11:43.079 They're mapped out by this, and this is basically an MRI 00:11:43.713 --> 00:11:46.555 I got a scan of my brain done and I was really impressed, 00:11:46.555 --> 00:11:49.250 to prove that I had a brain, but one of my friends got an fMRI 00:11:49.250 --> 00:11:52.781 to prove that his brain worked. (Laughter) 00:11:53.614 --> 00:11:56.747 The thing that's impressive about this 00:11:56.747 --> 00:12:00.152 is that the MRI's are getting so good now, 00:12:00.152 --> 00:12:02.464 you can map to the individual neuron level. 00:12:03.142 --> 00:12:05.285 The problem is there's a lot of neurons, 00:12:05.285 --> 00:12:07.366 so you have to hold the head still for a long time, 00:12:07.366 --> 00:12:10.574 and that's an advance in the ability to do the mapping, 00:12:10.574 --> 00:12:13.285 and also in the software for doing that mapping. 00:12:13.285 --> 00:12:15.481 And, so, that's where we are today. 00:12:15.481 --> 00:12:18.913 If we can hold the person still long enough, if we can find a volunteer 00:12:18.913 --> 00:12:20.593 that we can put, you know, 00:12:20.593 --> 00:12:24.830 the little plastic thing on their head, to hold their head still for some days, 00:12:24.830 --> 00:12:27.746 which is a little bit of a problem, we could probably go ahead 00:12:27.746 --> 00:12:30.454 and map their entire brain, 00:12:30.454 --> 00:12:33.134 and then just transform that map into a computer model, 00:12:33.134 --> 00:12:37.011 and we would have that person's mind downloaded into a computer. 00:12:37.475 --> 00:12:40.618 This is coming and this is coming soon, 00:12:40.618 --> 00:12:46.437 just like it's now possible for the order of ÂŁ1,000 to get your DNA mapped, 00:12:47.598 --> 00:12:49.735 it's going to cost you something, 00:12:49.735 --> 00:12:52.130 in about 30 years it's going to be possible 00:12:52.130 --> 00:12:56.244 to download your brain into a computer for about ÂŁ1,000 pounds, 00:12:56.244 --> 00:12:59.376 plus inflation. (Laughter) 00:13:00.899 --> 00:13:02.594 Could go up, could go down. Right? 00:13:02.594 --> 00:13:05.475 But there's tremendous advances in technology 00:13:05.475 --> 00:13:08.223 and these are making it possible to do things that before we were without. 00:13:08.223 --> 00:13:10.239 So, I have quote from a Google expert, 00:13:10.239 --> 00:13:13.900 we'll be uploading entire minds to computers in 2045. 00:13:13.900 --> 00:13:17.914 He also says we'll do bodies too, I'm thinking we won't do bodies, 00:13:17.914 --> 00:13:22.283 what we'll do is we'll take that mind and keep it from going out of its mind, 00:13:22.283 --> 00:13:23.810 we'll put it on artificial reality, 00:13:23.810 --> 00:13:25.742 it's in the computer, it's going to get bored, 00:13:25.742 --> 00:13:28.337 wants entertainment, wants social interactions, 00:13:28.337 --> 00:13:30.345 so we're going to create artificial realities. 00:13:30.345 --> 00:13:32.712 Now, in the old days, we'd make a thing like that, 00:13:32.712 --> 00:13:34.840 if you remember the matrix. Right? 00:13:34.840 --> 00:13:37.330 Ones and zeros, now, in fact, we may use quantum computers, 00:13:37.330 --> 00:13:39.124 so we'll have entangled states, 00:13:39.124 --> 00:13:41.784 but, in fact, it'll be some kind of a complicated environment 00:13:41.784 --> 00:13:45.289 where we can interact socially, because people want to be social, 00:13:45.289 --> 00:13:47.971 so there'll have to be thousands of people to interact with, 00:13:47.971 --> 00:13:50.077 and there'll have to be all kinds of other things 00:13:50.077 --> 00:13:52.132 in order to make that artificial environment 00:13:52.132 --> 00:13:54.724 sort of realistic and keep you going. 00:13:54.724 --> 00:13:56.913 And remember, when you download your brain, 00:13:56.913 --> 00:13:59.040 you're going to think about a million times faster, 00:13:59.050 --> 00:14:01.268 you're going to experience life about a million times faster. 00:14:01.268 --> 00:14:04.029 It's going to be a very different kind of a situation. 00:14:04.029 --> 00:14:05.854 You know? The idea of going back and machines 00:14:05.854 --> 00:14:08.155 and go out in the real world where things are still slow slow, 00:14:08.155 --> 00:14:11.482 you're going to get tired of doing that. 00:14:11.482 --> 00:14:16.514 And the size of simulated porn isn't so good in the real world. 00:14:16.514 --> 00:14:19.462 Okay, so, now, the other thing I have to do 00:14:19.462 --> 00:14:22.973 is to attack your certainty. 00:14:23.959 --> 00:14:27.108 So, I have to point out to you, human beings are not good at figuring out 00:14:27.108 --> 00:14:29.134 if they're real. 00:14:29.134 --> 00:14:31.331 So, your mind is really not equipped 00:14:31.331 --> 00:14:34.116 for addressing this and many other important questions. 00:14:34.116 --> 00:14:36.237 So, the first question I'm going to give you 00:14:36.237 --> 00:14:38.935 is count the number black dots. 00:14:38.935 --> 00:14:40.912 (Laughter) 00:14:40.912 --> 00:14:43.646 It's a still picture and there's no video. 00:14:50.328 --> 00:14:53.498 Here we go. You see this picture? 00:14:53.498 --> 00:14:56.408 How many of you see the horse in the picture? 00:14:56.408 --> 00:14:59.092 How many of you cannot see the horse in the picture? 00:14:59.092 --> 00:15:01.566 Once you see the horse, it's hard not to see the horse. 00:15:02.352 --> 00:15:06.563 And I want to show a picture of an object and ask you: Can it be real? 00:15:07.404 --> 00:15:09.574 And then I'm going to tell you, it's a photograph, 00:15:09.574 --> 00:15:13.239 the watch is real, the paper's real, the desk is real, 00:15:13.239 --> 00:15:15.449 Is that object real? 00:15:15.449 --> 00:15:18.336 Well, it's a photograph, so it's a real in some sense, 00:15:18.934 --> 00:15:23.723 as is this, and for me, this object flips back and forth. 00:15:25.975 --> 00:15:33.505 Here's the real version of that, made out of 2x4s, focused at different angles, 00:15:34.494 --> 00:15:38.043 and you see it's an optical illusion where your eye puts it together. 00:15:38.043 --> 00:15:41.903 And here's another example, and this is another example, just for fun, 00:15:44.164 --> 00:15:46.392 because you know it's just rotated, 00:15:46.392 --> 00:15:48.658 but the first response is: Phew, that's weird. 00:15:48.658 --> 00:15:50.685 So, here's one you're going to get the answer to. 00:15:50.685 --> 00:15:52.613 Which of these is longer? 00:15:54.793 --> 00:15:58.063 So, they're the same. How come? It doesn't really look that way to you. 00:15:58.063 --> 00:16:02.132 You knew that I was tricking you, so you understand, 00:16:02.132 --> 00:16:05.576 well, you still look at it, and think, well, but I'd better check now. 00:16:05.576 --> 00:16:07.901 because I know I'm going to make mistakes. 00:16:07.901 --> 00:16:10.384 Okay, so one more. 00:16:10.384 --> 00:16:13.670 I'll skip the lilac chaser on the other side, 00:16:13.691 --> 00:16:15.742 and just ask you about the stuff on the right. 00:16:15.742 --> 00:16:18.393 Are those lines straight or not? 00:16:18.610 --> 00:16:20.772 Well,they are straight, but to your eyes, 00:16:20.772 --> 00:16:23.182 it's really hard to convince you they're straight. 00:16:23.182 --> 00:16:26.896 Your brain is set to do other things. 00:16:27.285 --> 00:16:30.147 Here's another Bayesian reading test -- 00:16:30.607 --> 00:16:32.363 in the land of Bayes that we do it. 00:16:32.381 --> 00:16:36.522 There's many examples you can give this, but a cab was involved in a hit-and-run, 00:16:36.522 --> 00:16:39.333 and two cab companies are in the town, 00:16:39.333 --> 00:16:41.579 green cabs and blue cabs. 00:16:41.953 --> 00:16:45.700 And they operate: 85% of the cabs are green, 15% are blue. 00:16:46.339 --> 00:16:48.241 The witness says the cab was blue. 00:16:48.241 --> 00:16:50.956 When he's tested, he gets it right 80% of the time, 00:16:50.956 --> 00:16:53.277 or she gets it right 80 % of the time. 00:16:53.277 --> 00:16:55.992 What's the probability that it really was a blue cab? 00:16:55.992 --> 00:16:58.561 You have to go through the calculation carefully, 00:16:58.561 --> 00:17:02.958 this is the only equation, usually when I put equations up people go -- but -- 00:17:03.736 --> 00:17:06.979 it's almost 60% chance that the cab was green, 00:17:07.003 --> 00:17:09.708 even though this person gets it 80% right. 00:17:09.708 --> 00:17:12.726 And this is relevant, but there are other kinds of test like that. 00:17:12.735 --> 00:17:14.821 So, you can have tests that are even more powerful, 00:17:14.821 --> 00:17:17.458 like the test for breast cancer is 99% correct; 00:17:17.458 --> 00:17:19.422 it gets the wrong answer 1% of the time. 00:17:19.422 --> 00:17:22.071 But roughly a thousand times as many people, 00:17:22.071 --> 00:17:25.964 who... you know, 1,000 of the people that get tested actually have breast cancer, 00:17:25.964 --> 00:17:29.504 so, when you get the first response that you have breast cancer, 00:17:29.504 --> 00:17:33.016 itćs only a 10% that chance you really do, it's not to you get the next test. 00:17:33.032 --> 00:17:36.911 But the10%, you know, the 10 people are freaked out. 00:17:36.911 --> 00:17:40.532 Humans aren't ready for dealing with that kind of thing. 00:17:40.532 --> 00:17:43.649 Okay, so, it's because we lack computing power. 00:17:43.698 --> 00:17:46.951 So, we have compromises in our algorithms, right? 00:17:46.951 --> 00:17:51.245 Humans, therefore, are susceptible to optical illusions, 00:17:51.245 --> 00:17:53.467 systematic errors in judgment -- I'm running out of time -- 00:17:53.467 --> 00:17:55.820 I should have gone faster -- I got confident -- 00:17:55.820 --> 00:17:59.689 difficulty with complex decisions -- and keeping on time -- 00:17:59.689 --> 00:18:02.041 and the ability to function in a prehistoric world, 00:18:02.041 --> 00:18:03.737 which was the important one, you know. 00:18:03.737 --> 00:18:06.546 Only a few percent of the humans got wiped out, 00:18:06.546 --> 00:18:08.896 before they were able to reproduce, okay? 00:18:08.896 --> 00:18:11.987 So, simulations are going to make the same kind or similar approximates. 00:18:11.987 --> 00:18:14.902 So, we have many contradictions. 00:18:14.902 --> 00:18:18.196 We could see if our physics is inconsistent, 00:18:18.196 --> 00:18:21.040 then it's likely we're in a simulation, if physics is self-consistent 00:18:21.040 --> 00:18:24.382 it's more likely we're real, because it just takes more to do that. 00:18:24.382 --> 00:18:29.267 So, then one of the implications is, if we're in a simulated environment 00:18:29.277 --> 00:18:32.422 what we're going to do? Well, we're going to be discretized, 00:18:32.422 --> 00:18:35.166 that is fuzzy on a small scale, we're going to have entangled states, 00:18:35.166 --> 00:18:38.181 it means quantum mechanics. We have the holographic principle, 00:18:38.181 --> 00:18:41.008 that everything inside every environment is enclosed on the surface. 00:18:41.008 --> 00:18:43.321 So, here's an example. 00:18:43.321 --> 00:18:45.763 The hand and the apple 00:18:45.763 --> 00:18:48.944 are encoded on a geometrical sheet but projected into three dimensions, 00:18:48.944 --> 00:18:50.790 that's a way to keep track of everything, 00:18:50.790 --> 00:18:55.141 and the large scale in space and time may not match the small scale. 00:18:55.141 --> 00:18:57.395 So, let me finish up. 00:18:57.395 --> 00:19:00.403 Human beings are ill-equipped for determining reality. 00:19:00.403 --> 00:19:03.533 Physics, so this is actually a selling thing for physics, 00:19:03.533 --> 00:19:07.406 is a fundamental test of our realness. Currently we have contradictions. 00:19:07.409 --> 00:19:10.684 Is that because we're not good at resolving things, 00:19:10.684 --> 00:19:14.847 or is it because we're in a simulation? And what would that mean? 00:19:14.847 --> 00:19:16.622 Thank you. 00:19:16.622 --> 00:19:18.676 (Applause)