1 00:00:02,300 --> 00:00:15,000 🎵 2 00:00:16,000 --> 00:00:21,120 👏.. Clapping ... 3 00:00:21,260 --> 00:00:26,400 Here we are again, good evening to you in beautiful gorgeous summer night in New York and here, 4 00:00:26,500 --> 00:00:32,500 this place is full of people who wanna talk about holograms and wao... 5 00:00:32,820 --> 00:00:35,500 Yeah World Science Festival so grate, my name is john Hockenberry 6 00:00:35,500 --> 00:00:42,000 first of all I am college drop out, new guy who is gonna hang out with nobel physicists tonight, perfect for this job 7 00:00:42,320 --> 00:00:45,680 Oh my god... how did I get here! 8 00:00:45,700 --> 00:00:52,300 But seriously, you know we think of, this season is World Science festival, this the beginning of June 9 00:00:52,500 --> 00:00:57,000 the weather stars to get great, you know tonight at Brooklyn Bridge Park 10 00:00:57,120 --> 00:01:02,000 its supposed to be one of best viewing nights in Newyork and there aren't many really fabulous 11 00:01:02,000 --> 00:01:06,000 viewing nights in Newyork, so I urge you to do that, I mean its a beautiful clear night 12 00:01:06,000 --> 00:01:12,020 Every body is out there, its kind of like prom season, we think of the world science festival as the prom 13 00:01:12,780 --> 00:01:20,480 for all the scientist who; may be they didn't get any dates; didn't know there was a prom and I actually 14 00:01:20,480 --> 00:01:26,920 pulled our panel tonight, three clearly did not go to the prom; didn't want to talk about it and one 15 00:01:27,160 --> 00:01:31,880 didn't remember at all, you may be able to figure out who is who tonight. 16 00:01:32,680 --> 00:01:39,560 I am actually perfect for this gig for another reason because I actually inadvertently helped to solve 17 00:01:39,960 --> 00:01:46,520 one of the most serious problems in Physics, back in the 1970s. I was on a team that helped to do that, 18 00:01:46,520 --> 00:01:53,060 I was enrolled in University of Chicago, as an undergraduate and I tested into the top science section 19 00:01:53,060 --> 00:01:59,980 basically junior of science in my freshman year, and it was taught by a prerogative; David Triumph, one of the 20 00:01:59,980 --> 00:02:05,640 nobel orated university of Chicago, the late David Triumph brilliant physicist and part of the 21 00:02:05,640 --> 00:02:11,400 university of Chicago program which give us Enrico Fermi and so many others and Chandra shekhar and 22 00:02:11,640 --> 00:02:18,640 I was in this program and very excited, I go to the first lecture and it was taught by one of these prerogative 23 00:02:19,220 --> 00:02:26,540 central European fellow, I can't remember his name now and it will become clear why; He said! 24 00:02:26,740 --> 00:02:34,320 Hello everyone, its great to see all of you here, we have very serious problem in Physics, the problem is: 25 00:02:34,540 --> 00:02:40,060 Simple problem but serious problem, "it is too many physicists" 26 00:02:41,720 --> 00:02:52,020 So in this course if you are getting B/B- you will get F. If you are doing B+/A, you will get A. 27 00:02:53,120 --> 00:03:00,460 I went into the news business and thereby helped to solve the very serious problem in Physics. 28 00:03:00,900 --> 00:03:03,460 👏.. Clapping ... to many Physicists so 29 00:03:04,140 --> 00:03:12,820 and a lot of the panelists tonight possibly grateful for that, so you are here to talk about and to listen to 30 00:03:13,160 --> 00:03:22,100 one of the most exciting, fascinating also difficult principals that now being kicked around in physics 31 00:03:22,120 --> 00:03:28,560 and cosmology, the holographic effect and it evolves a couple of concepts that actually we have a lot of 32 00:03:28,560 --> 00:03:35,560 intuitive; sort of sense of and I want to present two of those tonight before we introduce the panel and get 33 00:03:35,760 --> 00:03:44,020 started here. One is the idea of information, we think we know what information is right? 34 00:03:44,280 --> 00:03:54,540 Information is very very; like you know information right? Now that isn't the Newyork subway system right? 35 00:03:54,740 --> 00:04:01,700 But it is enough information to specify; how to get from point A to point B and if you understand how to read 36 00:04:01,940 --> 00:04:10,220 the subway map, you can get from point A to point B. The information isn't exactly the same as the subway 37 00:04:10,220 --> 00:04:16,420 but if you don't have the information the subway is useless to you and some how its sort of maps directly, 38 00:04:16,420 --> 00:04:20,980 it is a map right? Its maps directly on to the subway and of-course now the subway map, 39 00:04:21,220 --> 00:04:28,260 nobody has one of these right? its all on your smartphone, which means its stored on a tiny piece of 40 00:04:28,460 --> 00:04:36,500 silicon, so therefore the volume of this (hard copy) can actually be map directly to a volume, you know 41 00:04:36,900 --> 00:04:45,740 one millionth the size, take for example this (book) anybody got these anymore, no? This specifies the 42 00:04:45,740 --> 00:04:51,840 number of synonyms, I don't know what the hell it actually is but it is the source and it actually also 43 00:04:52,080 --> 00:05:04,080 fit in a tiny piece of code in Microsoft word. We got here just the Oxford shorter English dictionary, information 44 00:05:04,080 --> 00:05:08,140 I am gonna set over here just to remind you what information is all about, now information, 45 00:05:08,360 --> 00:05:15,720 The dictionary isn't the English language right? the space, the universe of the English language is all you 46 00:05:15,720 --> 00:05:22,220 people talking, will you talk now, just talk, just turn your neighbor and say hello, how you doing? right there see? 47 00:05:25,300 --> 00:05:32,020 That is the space, the universe of English language that you are hearing it is not the same as this book 48 00:05:32,020 --> 00:05:37,940 but its sort of maps on to this book and there is enough information in this book to make predictions about 49 00:05:37,940 --> 00:05:43,040 what it is you saying so that if you actually talk to me I know what the hell it is that you saying. 50 00:05:43,040 --> 00:05:49,940 Unfortunately; I probably won't know what the hell there is most of the panelists are saying tonight so I may need 51 00:05:49,960 --> 00:05:55,760 you help with that. Nevertheless there is information in what they say, the information maps on 52 00:05:55,760 --> 00:06:01,760 to a space where we can make predictions, it is information that allows us to be conscious being 53 00:06:01,760 --> 00:06:08,640 it is information that allows us to be living being if you think of DNA's information now the information 54 00:06:08,640 --> 00:06:13,340 we are gonna talk about tonight is much more complicated but the idea of information as a map 55 00:06:13,340 --> 00:06:19,100 as a specification of a much bigger space it is sort of the beginnings of we are talking about here. 56 00:06:19,100 --> 00:06:25,020 You know these holograms right? you know; clap if you know what a hologram is 👏.. Clapping ... right. 57 00:06:25,240 --> 00:06:31,480 I just said: clap if you think, you know what a hologram is. 58 00:06:31,760 --> 00:06:47,360 Let me introduce our panel please welcome Raphael Bousso 👏.. Clapping ... 🎵 59 00:06:47,560 --> 00:06:50,720 Let me tell you few things about Raphael, Raphael Bousso is a theoretical physicists at 60 00:06:50,720 --> 00:06:56,200 University of California Berkeley. He is recognized for discovering the general relation between curved 61 00:06:56,220 --> 00:07:03,040 geometry of space time and its information content, a key idea of the holographic principle. 62 00:07:03,420 --> 00:07:14,800 Please welcome next panelist: Herman Verlinde 👏.. Clapping ... 🎵 63 00:07:14,800 --> 00:07:20,180 Herman Verlinde is Physics professor at Princeton university, in 1998 Verlinde recieved his PhD 64 00:07:20,180 --> 00:07:26,160 under the supervision of Gerard 't Hooft, Verlinde is renowned for his contribution to string theory 65 00:07:26,300 --> 00:07:33,160 and its application in cosmology, blackhole Physics, some of its current work explores gravity 66 00:07:33,260 --> 00:07:36,220 in context of the holographic principle. 67 00:07:36,220 --> 00:07:51,360 Our next panelist is indeed Nobel prize winner Gerard 't Hooft 👏.. Clapping ... 🎵 68 00:07:51,580 --> 00:07:57,420 Gerard 't Hooft received the 1999 Nobel prize in Physics for his doctorate work in theoretical Physics 69 00:07:57,420 --> 00:08:01,980 He is professor of Physics and of his many achievements, he was the first to propose the idea 70 00:08:01,980 --> 00:08:05,080 that would later become known as the Holographic principle. 71 00:08:05,380 --> 00:08:19,680 And finally our fourth panelist Leonard Susskind 👏.. Clapping ... 🎵 72 00:08:19,680 --> 00:08:25,380 Professor Susskind is Professor of theoretical Physics at Stanford University and the first to give a more precise 73 00:08:25,400 --> 00:08:30,540 interpretation of the holographic principal using string theory. He is well known for his book on the topic of 74 00:08:30,540 --> 00:08:36,400 the Holographic principle, the black hole war might battle with Stephen Hawking to make the world safer 75 00:08:36,460 --> 00:08:41,800 for quantum mechanics. Its a fantastic book. I highly recommend it. 76 00:08:41,800 --> 00:08:43,680 Please welcome the Panel. 👏.. Clapping ... 77 00:08:43,720 --> 00:08:51,980 Back in early 1970s Stephen Hawking wrote down a astonishing equation, it would include relativity 78 00:08:51,980 --> 00:08:58,220 it would include quantum mechanics and it would include information, Hawking rather simple equation 79 00:08:58,220 --> 00:09:03,020 brought us a step closer to understanding the relationship between quantum Physics and black holes 80 00:09:08,020 --> 00:09:14,980 When an object crosses over the edge of a blackhole's event horizon, the object enters a realm basically 81 00:09:14,980 --> 00:09:20,000 of empty space of darkness and continues to be dragged toward the center of blackhole, 82 00:09:20,000 --> 00:09:24,200 toward we call the singularity where it gets crushed out of existence. 83 00:09:24,200 --> 00:09:30,080 Every object in some sense contains information, because it contains a very specific arrangement 84 00:09:30,160 --> 00:09:37,160 of particle so where is the information that describes the arrangement of those particles, where does it go? 85 00:09:39,500 --> 00:09:46,140 Hawking's description of this process was that; the energy remains but the information disapears 86 00:09:46,360 --> 00:09:54,500 For many years, for decades people wondered; is Hawking right? Is the information obliterates 87 00:09:54,500 --> 00:10:00,260 and disappear from the universe or is it still there and perhaps can be, in some way retrieved? 88 00:10:01,540 --> 00:10:06,660 the destruction of information was counter-intuitive and didn't match the rest of the things we knew 89 00:10:06,660 --> 00:10:11,940 in all part of Physics we have situation where information doesn't get destroyed so it was a bit puzzling 90 00:10:17,140 --> 00:10:22,980 This debate furiously went back and forth up through the 80s and into the 90s when people 91 00:10:24,640 --> 00:10:31,440 finally began to articulate, this new principal, this holographic principle and what it said is that 92 00:10:31,460 --> 00:10:38,400 all the things that were falling inside the blackhole were somehow captured in a preserved image 93 00:10:38,780 --> 00:10:45,780 at the horizon itself. So if the information is not lost on the surface, the information is lost inside because 94 00:10:45,780 --> 00:10:50,900 they are equivalent. All the information about those objects, what they were like, in their three dimensional 95 00:10:51,360 --> 00:10:58,560 existence was preserved or encoded on the surface of the blackhole and that is little bit like a hologram 96 00:10:59,340 --> 00:11:06,140 well that suggest that may be that idea, may apply more broadly to the universe as a hole, may be the three 97 00:11:06,140 --> 00:11:12,140 dimensional objects, us, everything in the world around us, may be all of the information in these objects 98 00:11:12,140 --> 00:11:18,940 is carried, is smeared around a distant two dimensional surface that surround us and we are just, in some sense, 99 00:11:19,020 --> 00:11:22,460 holographic projection of that distant data. 100 00:11:24,280 --> 00:11:30,600 The holographic principle tells us some thing quite astonishing, it says the ideas of volume, 101 00:11:30,640 --> 00:11:35,120 that real world in some sense might be a kind of illusion. 102 00:11:40,060 --> 00:11:48,300 So, are we real or we just holograms. Lets begin with that but in fact lets first of all remind folks 103 00:11:48,300 --> 00:11:53,500 You guys were direct participants in that argument that was described in that film which I think fairly 104 00:11:53,500 --> 00:11:59,760 characterizes difficulty scientists have, not only in sort of grasping and fully understanding this 105 00:11:59,760 --> 00:12:02,580 holographic effect principle but also explaining it. 106 00:12:02,960 --> 00:12:09,260 Leonard Susskind! what was it like to get into essentially a pretty big cosmological argument 107 00:12:09,260 --> 00:12:17,000 with Stephen Hawking, and be careful because Hawking is one of the my wheel chair boys and we are really tied 108 00:12:21,200 --> 00:12:26,800 What was it like; it was fun and it was frustrating and it was incredibly frustrating 109 00:12:29,100 --> 00:12:39,340 Stephen has a view which was very very difficult to argue with. His idea was based on very very sensible ideas 110 00:12:39,340 --> 00:12:45,040 a blackhole is a place where nothing can get out of but things can fall into it and the things can fall into it 111 00:12:45,040 --> 00:12:50,820 and they can't get out, they are gone but then the blackhole evaporates. Stephen had proven that beyond 112 00:12:50,820 --> 00:12:58,080 any body's doubts and so things fall into the blackhole, they can't get out, the blackhole evaporates, 113 00:12:58,240 --> 00:13:06,740 puff its gone. Just exactly as Brian said. It was unassailable, there was no way for argue the case 114 00:13:07,020 --> 00:13:15,300 and yet some of us particularly Gerard't and myself very very strongly felt that this really undermine everything 115 00:13:15,300 --> 00:13:22,160 that we knew about Physics. Everything that we know about Physics today and even much earlier was based 116 00:13:22,160 --> 00:13:27,460 on principle of Physics which is so basic that we sometime forget to mention it to our students 117 00:13:27,980 --> 00:13:35,440 Its the idea that information never disappear, and I will tell you what it means, information means distinctions 118 00:13:35,640 --> 00:13:43,760 distinctions between things, Hydrogen atom is not the Oxygen atom and Oxygen atom is not Hydrogen atom 119 00:13:43,760 --> 00:13:49,600 there are distinctions between these things and there was a very very basic principle of Physics that 120 00:13:49,680 --> 00:13:55,520 distinctions never disappear. That they may get scrambled, that they may get mixed up 121 00:13:55,820 --> 00:14:02,460 but if you start with one configuration and you let it go or you start with a different configuration 122 00:14:02,460 --> 00:14:07,640 which has different information and you let it go, they will stay different and Stephen was saying 123 00:14:07,640 --> 00:14:13,120 exactly the opposite, no matter what you throw in the blackhole and in the end you get out exactly the same 124 00:14:13,160 --> 00:14:19,800 thing. It was extremely difficult to see what was wrong with what he was saying, it was even harder to 125 00:14:19,800 --> 00:14:24,600 make him understand that there have to be something wrong with what he was saying so it was very 126 00:14:24,640 --> 00:14:32,800 very frustrating but at the same time it was very exhilarating to come up against this 127 00:14:32,880 --> 00:14:41,620 basic problem of conflict of principles. And if anything can break the impasses in Physics if there are 128 00:14:41,740 --> 00:14:47,740 no experiments available, its conflict of principle. When conflicts of principle arise 129 00:14:47,820 --> 00:14:50,620 that's when major new paradigm can shift. 130 00:14:50,620 --> 00:14:52,360 And that is excitement, that's really the excitement. 131 00:14:52,360 --> 00:15:03,080 Gerard't explain to me why this problem with Hawking, this; you know the information can't go away as it seems 132 00:15:03,080 --> 00:15:08,620 as though Hawking mathematics suggest it does? its different from, something like say, conservation of 133 00:15:08,620 --> 00:15:13,700 mass and energy, where mater can neither be created nor destroyed. Its different than that right? 134 00:15:13,720 --> 00:15:22,820 Yes it was a very fundamental problem, and way I always saw it is; Hawking was using quantum mechanics 135 00:15:22,860 --> 00:15:33,140 in particular quantized fields to derive his result. So quantum mechanics went in as starting point number 1 136 00:15:33,140 --> 00:15:38,780 and than general relativity and everything else, and use of that to derive the blackholes radiate particles 137 00:15:38,780 --> 00:15:44,320 from that it was derived that it was information and there was information disappearing. 138 00:15:44,620 --> 00:15:52,900 Well in fact information disappearance is at odds with quantum theory itself. So he used quantum theory 139 00:15:53,080 --> 00:15:58,760 to derive result which basically was at odds with quantum theory, so there had to be 140 00:15:58,760 --> 00:16:05,400 a mistake some where. I shouldn't call it "mistake" because what he did was by itself mathematically 141 00:16:05,440 --> 00:16:15,060 correct and nobody doubts that but the final result had something in it that couldn't be true so this is what, 142 00:16:15,140 --> 00:16:22,140 in Physics we call paradox. And like my friend Leonard has been saying as soon as we encounter a situation of 143 00:16:22,140 --> 00:16:28,220 this sort in physical world we were very happy actually. It is a paradox it means there is work for us to do 144 00:16:28,220 --> 00:16:34,880 and we have to clear things up. And if you look at the past, you know quite well that when people start to 145 00:16:34,940 --> 00:16:38,560 clear up paradoxes, new discoveries are being made. 146 00:16:38,560 --> 00:16:39,200 So you guys are friends? 147 00:16:39,200 --> 00:16:44,140 So it seems in several cases and that's why we also excited about this thing. Is something wrong? 148 00:16:44,140 --> 00:16:48,640 Derivation itself seems to be flawless but there is some thing wrong anyhow with the result. 149 00:16:48,640 --> 00:16:50,060 You guys are friends then? 150 00:16:50,060 --> 00:16:51,080 Of course we are. Yeah. 151 00:16:51,080 --> 00:16:56,020 Herman! Let me ask you a question just about this issue of information and then I want you to go back. 152 00:16:56,040 --> 00:17:05,140 I definitely want you to go back. Why does the universe need information. Why does it need to have 153 00:17:05,140 --> 00:17:09,260 this information. why does a rock need some sort of information or image? 154 00:17:10,280 --> 00:17:16,980 what you call information, we as physicists would just write such terms in equations right. 155 00:17:16,980 --> 00:17:22,720 We think of physical world as been driven by mathematical formulas, in these formulas that have 156 00:17:22,720 --> 00:17:29,440 what we call; degrees of freedom. So things can be this that or that. Oxygen or Hydrogen he given us example. 157 00:17:29,920 --> 00:17:36,920 All these things gone as equations and we are used, particularly in quantum mechanics to the situation that 158 00:17:36,940 --> 00:17:44,800 If two things start up differently, they end up differently, that's a fundamental notion in quantum theory. 159 00:17:44,800 --> 00:17:50,320 We can't get around it. you can't have two different states adding up after a while to be the same. 160 00:17:50,320 --> 00:17:56,020 That's violates the principles of quantum mechanics. Now quantum mechanics itself is 161 00:17:56,020 --> 00:18:01,980 not such a sacred theory that may be avoid violations of it, but then we want to know about this. 162 00:18:01,980 --> 00:18:06,460 We just don't want to say, well you know, we have to clear that mess up later. No no the mess has to 163 00:18:06,460 --> 00:18:11,780 be cleared up right now. If there is a flaw of this sort in a result, we want to know about it. 164 00:18:11,780 --> 00:18:17,580 So what Hawking was saying; two different blackhole start out differently and one of them has tea pod falling 165 00:18:17,880 --> 00:18:24,980 into it, in other an old shoe. I saw this movie and if tea pod falls into a blackhole or a old shoe falls 166 00:18:24,980 --> 00:18:30,740 into blackhole, that's different, tea pod is not the same thing as the shoe. Nevertheless after a while 167 00:18:30,740 --> 00:18:37,420 they look exactly the same according to Hawking. You see that violates our equations that can not be true. 168 00:18:37,420 --> 00:18:41,640 There is something wrong, something went wrong on the way and we want to know what it is. 169 00:18:41,640 --> 00:18:48,020 Thanks to referring to that, because I can't tell you how hard it was to get the tea pod into the blackhole and then to get the shoe 170 00:18:48,100 --> 00:18:48,980 I realize it. 171 00:18:48,980 --> 00:18:53,540 Sometime we just get the tea pod, we said get rid of shoe too, and that was really hard. Yeah Herman please 172 00:18:53,540 --> 00:18:59,260 Ok, Let me first follow on the, sort of the, because you were asking how was it to have a debate with Hawking, 173 00:18:59,260 --> 00:19:04,940 that was kind of you question, may be tell a little anecdote about how it was, in part of it, of course 174 00:19:05,420 --> 00:19:15,380 all about science and we are all friends, even if we disagree about the science. But Hawking is very spacial 175 00:19:15,700 --> 00:19:23,120 person where he can think very deeply about questions but he also has handicap. He can not speak so he has to 176 00:19:23,360 --> 00:19:29,200 speak by typing words and some times the debate would go like this and then even argument 177 00:19:29,240 --> 00:19:34,280 would be given and then Hawking response would be one word - rubbish - 178 00:19:37,120 --> 00:19:39,240 - Very hard to argue with- and that's very hard to argue with 179 00:19:40,480 --> 00:19:45,320 and you know, when I say rubbish no body pays attention you know 180 00:19:46,080 --> 00:19:55,940 But when Hawking says "rubbish", its silent and you lost the argument at that point. Capital R, its a big Font there 181 00:19:55,940 --> 00:20:01,000 Yeah right. When Hawking says it. Alright so Hawking says rubbish to you, do you like go home 182 00:20:01,000 --> 00:20:05,240 and tell your wife; Hawking said rubbish to me, what do I do or you like to the blackboard 183 00:20:05,240 --> 00:20:11,300 or just sit down to computer? what happens? You go on with because you believe in your argument. 184 00:20:11,300 --> 00:20:17,700 The other question about information, the thing which I like sort of as a way of explaining what information is; 185 00:20:18,520 --> 00:20:25,000 we live right now in the age of information this is the information age but the type of information 186 00:20:25,000 --> 00:20:29,460 we are talking about here, you say, well its more complicated but one way of imagining what kind of 187 00:20:31,520 --> 00:20:38,520 information we talking about is; I like the movie "The Matrix" where there is virtual reality where actually kind 188 00:20:38,920 --> 00:20:45,920 of nightmares for myself when I was young. What if the whole world is just a thing that's been projected on my 189 00:20:45,920 --> 00:20:51,200 brain or actually for all of us that are sitting here in this room, and who knows might be its just a computer 190 00:20:51,200 --> 00:20:58,160 that makes us believe that we are real and the kind of information that we are talking about is really sort of 191 00:20:59,180 --> 00:21:05,980 what is inside of this computer, imagine you make this hall here with all the reality of being able to do 192 00:21:05,980 --> 00:21:11,240 experiments. Things fall, you collide things, things happens exactly the way we thought and think about 193 00:21:11,320 --> 00:21:18,400 its happening in Physics. But its all just zeros and ones and a computer. And in principle you can quantify; 194 00:21:18,420 --> 00:21:23,000 how many terabytes, how many gigabytes, how many, I am not sure, I forgot what comes after gigabytes 195 00:21:23,060 --> 00:21:28,200 but there is information in that computer and that's the kind of information we currently talking about. 196 00:21:28,200 --> 00:21:34,680 So when you say information, you say that physicist believe and cosmologist believe that it is possible 197 00:21:34,740 --> 00:21:45,200 to map every aspect of reality that we are experiencing here into some sort of stored code that specifies 198 00:21:45,920 --> 00:21:52,800 preciously everything that is happening here, what people smell like, who is mad at who, who is wearing 199 00:21:52,860 --> 00:21:56,960 like dirty shoes and what they are even thinking about. 200 00:21:58,100 --> 00:22:00,740 You can imagine that's the way it goes. 201 00:22:00,780 --> 00:22:08,700 Now just its something scientist or imagining it or does quantum mechanics insist that there must be so? 202 00:22:08,840 --> 00:22:09,720 Raphael! 203 00:22:09,960 --> 00:22:16,800 Quantum mechanics in a way is based on information. its a theory of information. 204 00:22:16,800 --> 00:22:22,980 The way that we would describe the world and if the room being full of people or no full of people 205 00:22:23,060 --> 00:22:32,820 and electron being in this place or that place. These are different states as we call them and its; as if; you know, 206 00:22:32,820 --> 00:22:37,820 you put one letter on the page or you put a different letter on the page because its different, it conveys information. 207 00:22:37,820 --> 00:22:44,800 So where a particle is a way of conveying information and in fact quite literally when we right some thing on 208 00:22:44,800 --> 00:22:51,280 a page we put particles in particular places and we thereby convey information so its not very efficient 209 00:22:51,280 --> 00:22:56,520 compared to, Lets explore that for a moment, Victoria do you have Rapheal's slides. 210 00:22:56,520 --> 00:23:01,360 Put up his first slide over here because as someone who understand mathematics poorly, 211 00:23:03,120 --> 00:23:09,920 The understanding that I had was that; as you go, say you are looking at the coast line of Massachusetts 212 00:23:10,020 --> 00:23:16,900 and you are looking at it from a satellite and you see one line, but then you come closer and then you begin 213 00:23:16,900 --> 00:23:21,940 to trace every little indentation and then you get even closer and you trace even any more indentation, 214 00:23:21,940 --> 00:23:28,680 try to specify down to the atomic level that the amount of information in the line that traces the coast line 215 00:23:28,700 --> 00:23:33,680 is actually unbounded and infinite. What is it that you have discovered? 216 00:23:34,440 --> 00:23:40,680 Well that is not, its not infinite, there is a limit. - And so how does this, how did we begin with this picture here. 217 00:23:40,680 --> 00:23:44,620 I think there is very important thing that maybe we need to say in order to get from blackholes to this - Sure - 218 00:23:45,780 --> 00:23:51,860 I was actually not part of this debate with Hawking, I became his student two years later but 219 00:23:51,860 --> 00:23:54,840 You look younger as a result, I think As a result, yes 220 00:23:54,880 --> 00:23:58,700 its certainly age these gentleman here - so I - 221 00:24:00,340 --> 00:24:06,280 its recently the reason we are ordered this way, we came in we figured Rapheal could walk the furthest and 222 00:24:09,460 --> 00:24:15,000 We decided, we are gonna leave you here when we - 223 00:24:15,180 --> 00:24:19,940 And Hawking could be here, you see, got me so Yeah he was here last year 224 00:24:20,620 --> 00:24:29,900 Anyway so these gentleman had, you know the crazy insight that when information is dropped into 225 00:24:29,900 --> 00:24:33,660 a blackhole, it is not in fact lost Even though naively you would just think ok 226 00:24:33,660 --> 00:24:39,160 now its in this blackhole its somewhere when we can get to it. They insisted that you still have to be able to get to it. 227 00:24:39,160 --> 00:24:44,280 Which. you know, let me make this tell them so easy, but it wasn't that obvious. it was an incredible intuition 228 00:24:44,960 --> 00:24:51,680 And for that to be true, that, if you throw a phone book into a blackhole that later on you can figure out 229 00:24:51,680 --> 00:24:55,800 whether it was the Newyork or Chicago phonebook. Two amazing thing have to be happen. 230 00:24:56,700 --> 00:25:04,180 First of all Hawking have to be wrong about the idea that, no matter what you throw into the blackhole, 231 00:25:04,180 --> 00:25:09,880 same thing come out. very loosely of putting what he said but that's the basic way information would be lost. 232 00:25:09,880 --> 00:25:16,440 A second amazing thing had to happen, which is, you know, it takes a long time for a blackhole to fizzle away 233 00:25:16,440 --> 00:25:21,860 and disappear and return potentially, return information to you, supposing Hawking is wrong. And in mean time 234 00:25:21,860 --> 00:25:27,800 you got this big flat blackhole sitting there. And what had to be true was that, while that big flat blackhole 235 00:25:27,800 --> 00:25:34,460 sitting there, that blackhole itself contain information while its still sitting there and hasn't fizzled away yet. 236 00:25:34,460 --> 00:25:38,700 Alright, so the question- And for that to be true, there had to be a limit on 237 00:25:38,700 --> 00:25:42,920 how much information there could possibly be in the region that was occupied by the blackhole. 238 00:25:42,920 --> 00:25:46,140 Because you can presumably always convert that region into a blackhole. 239 00:25:48,040 --> 00:25:55,000 Alright, so lets backup for a second, so Hawking suggest that the information is gone. You say that can't 240 00:25:55,320 --> 00:26:01,160 possibly be true, Hawking says -rubbish- and then you go about saying: we are gonna find 241 00:26:01,180 --> 00:26:04,360 where that information actually is. 242 00:26:04,640 --> 00:26:13,180 Leonard! before we get to Rapheal's slide here, where did you find or where did we find that information, 243 00:26:13,240 --> 00:26:17,720 that Hawking says is gone in the blackhole is actually stored? 244 00:26:19,040 --> 00:26:25,600 Ok so, one of the things that we found is, I am sorry to say this John but turned out to be a bad question 245 00:26:27,960 --> 00:26:34,960 Ok, That in a certain bit of information don't necessarily have locations or at least they don't necessarily have 246 00:26:34,960 --> 00:26:40,080 locations which are objective and same for every body, no matter how they are moving. 247 00:26:40,080 --> 00:26:42,040 Ok, I am all about that questions 248 00:26:42,040 --> 00:26:47,660 The notion of a bit of information is a good one, we believe it, we believe distinctions exists 249 00:26:47,740 --> 00:26:56,940 and distinctions persists. But the notion of where that bit of information is located turned out not to be a good 250 00:26:56,940 --> 00:27:02,680 what a physicist would call, invariant question. It might depend on who was looking at it. 251 00:27:02,680 --> 00:27:05,600 Now let me give you an example of where it is a good idea. 252 00:27:06,140 --> 00:27:13,140 If an atom decays inside the sun, everybody will agree it happened inside the sun, it doesn't matter if you are 253 00:27:13,140 --> 00:27:19,540 moving relative to the sun, it doesn't matter if you are far away, if you are nearby. Everybody will agree if they do 254 00:27:19,540 --> 00:27:26,240 the calculation, and see what comes out and agree, the atom decayed inside the sun, the thing happened inside the sun. 255 00:27:27,160 --> 00:27:33,800 Blackholes are different and what we found is the whole notion of whether something happens inside 256 00:27:33,840 --> 00:27:40,840 the blackhole or it happens just above the surface of blackhole, surface means in the horizon, is a question 257 00:27:40,840 --> 00:27:46,880 which is observer dependent. Somebody who falls into the blackhole may have all of the experiences of seeing 258 00:27:46,880 --> 00:27:54,620 the event happen well in past the horizon. Somebody standing outside the blackhole will reconstruct 259 00:27:54,620 --> 00:28:01,100 out of the Hawking radiation that, that event actually happened outside of the blackhole. So the answer to 260 00:28:01,100 --> 00:28:06,860 your question is; we didn't find out where the information was, we found out that it was a improper question 261 00:28:07,000 --> 00:28:11,820 The bits of information don't really have locations of that sense. 262 00:28:11,820 --> 00:28:16,760 And how do you know that they weren't destroyed if you couldn't find them in any particular location. 263 00:28:17,720 --> 00:28:25,980 Well, eventually a lot of the power of string theory and other mathematics came to bear on it and confirmed 264 00:28:26,180 --> 00:28:34,640 that there was no expectation that would be destroyed. But as; can I call you Gerard't, its so much easier. 265 00:28:35,240 --> 00:28:42,480 Ok, as my friend Gerard't here says, I spent years learning to say Gerard't; but I never-mind. 266 00:28:42,480 --> 00:28:45,300 I am totally fine with Gerard't, totally fine with it. 267 00:28:47,920 --> 00:28:59,780 God I am 71 years old and I forgot what I was gonna say You were saying that issue was where it was 268 00:29:00,040 --> 00:29:08,240 and the in-variance of the question meant that, the variance of my question meant that you wanted 269 00:29:08,240 --> 00:29:12,140 to basically change the nature of inquiry. 270 00:29:12,340 --> 00:29:19,900 yeah you asked me, how we know and, I think the answer was given by Gerard't that, so much would break 271 00:29:19,900 --> 00:29:25,440 down in Physics the whole structure of everything we know about Physics would breakdown and disintegrate 272 00:29:27,840 --> 00:29:34,600 if even you open a door for tiny little bit for the idea of information to be lost. Once it can be lost, you can 273 00:29:34,600 --> 00:29:40,340 promote that and make it worst and worst and worst and worst and eventually the whole structure of Physics, 274 00:29:40,340 --> 00:29:45,700 as we know it, will breakdown. There was somethings you can't have a little bit of, You either have it 275 00:29:45,720 --> 00:29:52,600 or you don't, you know, we all know about pregnancy, but let me give you another example. In mathematics 276 00:29:52,600 --> 00:29:58,600 can you have a theory, a theory which means of mathematical structure, arithmetic or what ever. 277 00:29:58,600 --> 00:30:04,520 Can you have a theory which is approximately consistent, its almost completely consistent, 278 00:30:06,160 --> 00:30:12,480 well you might have some structures some set of axioms and you derive, you let your computer run 279 00:30:12,940 --> 00:30:19,680 and derive ten thousand of theorems from it and say all approximately consistent, only four of them 280 00:30:19,680 --> 00:30:23,640 were inconsistent with each other. Well no, mathematician will come and tell you, 281 00:30:23,680 --> 00:30:31,980 once you have any inconsistency, you can use that inconsistency to promote that, anything is inconsistent 282 00:30:31,980 --> 00:30:37,180 with everything else basically. I think the same thing was true about information lost 283 00:30:37,460 --> 00:30:45,420 once you have it, once you have it in any form at all, you can imagine situation where it would undermine 284 00:30:45,420 --> 00:30:49,960 basically all of Physics. And that's what, I think, that's what Gerard't thought, 285 00:30:49,960 --> 00:30:52,820 that's what I thought and that's what Stephen didn't think 286 00:30:53,380 --> 00:31:00,760 So we sort of battled heads against the wall for a while. Alright, so how in my imperfect questions creating way, 287 00:31:01,100 --> 00:31:10,620 can we get to the point of either, if not, where was the information, how did we learned conclusively that it 288 00:31:10,660 --> 00:31:18,680 wasn't destroyed and that if, the phone book went into the singularity that there was a way to find out 289 00:31:18,780 --> 00:31:24,040 if it was Chicago, or Amsterdam or you know, Seattle 290 00:31:25,060 --> 00:31:30,820 When ever I encounter situation like this I try to approach it from all possible angels 291 00:31:31,200 --> 00:31:37,440 Particularly angels of my neighbors here will not be prepared to look at, to see what can we do, 292 00:31:38,940 --> 00:31:45,940 we have as I said a paradox here and the resolution must come from totally different point of view then previously. 293 00:31:45,940 --> 00:31:51,600 Now one thing was that quantum mechanics was used to derived the result, quantum mechanics some how 294 00:31:51,600 --> 00:31:59,640 failed to agree with, by far so there was something wrong so my attitude was start from other end, 295 00:31:59,640 --> 00:32:04,680 now lets assume that blackhole, as a hole, agrees with anything we know about quantum mechanics. 296 00:32:05,080 --> 00:32:12,080 That mean information in is equal to information out. Its that simple basically in quantum mechanical sense 297 00:32:13,700 --> 00:32:20,700 so that ought to be true. As soon as you believe that this is true, its a relatively simple calculation to find 298 00:32:20,720 --> 00:32:27,720 how much information there is in the blackhole. And you do the calculation, you find the amount of information 299 00:32:27,720 --> 00:32:34,600 in the blackhole is exactly equal to its surface area. Its like putting bits and bytes of the computer memory 300 00:32:34,660 --> 00:32:41,820 on the surface, every bit, every byte of information occupies very precise amount of surface which is then 301 00:32:41,820 --> 00:32:47,240 calculated relatively easily and that tells you big blackholes contains a lot of information, 302 00:32:47,960 --> 00:32:54,960 small ones contains a little information, still enormous amount in any absolute sense. That was very clear 303 00:32:54,960 --> 00:32:57,720 conclusion; how much information there is in the blackhole. 304 00:32:57,720 --> 00:33:02,320 But the question; where the information is something else again. 305 00:33:02,520 --> 00:33:11,600 Alright, let me guess; just backup here, so all you got , if you got your blackhole to study, at least not to find 306 00:33:11,700 --> 00:33:21,780 where the information is but to figure out if there is a quantity of information that could sufficient to specify; 307 00:33:21,780 --> 00:33:24,020 what goes on in this blackhole. You got your surface 308 00:33:24,020 --> 00:33:26,480 Not the sufficient; exact quantity itself Exact Ok 309 00:33:26,480 --> 00:33:30,100 there is a few bits hanging around aside but apart from that, 310 00:33:30,160 --> 00:33:34,720 the total quantity of information is very preciously calculable. 311 00:33:35,220 --> 00:33:43,700 But all you got is the surface of blackhole, so you got a test; could there be enough information on the surface 312 00:33:44,120 --> 00:33:51,660 to specify what gone into the singularity and what is happening beyond this event horizon, that's the question right. 313 00:33:51,660 --> 00:33:57,680 Well the question was answered by this assumption that blackhole should obey quantum mechanics 314 00:33:57,680 --> 00:34:03,120 once you made that assumption, you find that not only information seems to went in and out of the blackhole 315 00:34:03,220 --> 00:34:08,740 but every thing in its vicinity should be mapped onto its surface in bits and bytes. 316 00:34:09,060 --> 00:34:15,120 Its like saying that surface is a hologram of the immediate surrounding spacetime. 317 00:34:15,400 --> 00:34:24,660 So a X dimensional object can specify an X+1 dimensional object. 318 00:34:24,660 --> 00:34:31,120 Are you getting in this here, is this working for you? We are cool right, alright alright good, you are all with us. Ok 319 00:34:31,120 --> 00:34:34,460 So the surface is two dimensional -Surface is two dimensional 320 00:34:34,460 --> 00:34:37,520 But surround spacetime three dimensional -Which is exactly what a hologram does 321 00:34:37,520 --> 00:34:44,480 You got your two dimensional star wars movie and your three dimensional looking princess leia who by the way, 322 00:34:45,860 --> 00:34:52,580 did have prom date, I believe, and so but is that an allusion, you know in prospective, its basically, 323 00:34:53,400 --> 00:34:59,880 you creating an allusion or is it actually one to one mapping of all the information of the reality 324 00:34:59,880 --> 00:35:04,820 on to the 2D surface that gives you, your 3D reality? Herman! 325 00:35:04,900 --> 00:35:10,420 Yeah, again talking about mapping; then we don't know exactly works at this point. 326 00:35:10,680 --> 00:35:17,680 But I would say that the principle that turns out to be very powerful int his context, I call it Rumsfeld principle, 327 00:35:19,620 --> 00:35:26,180 and its basically saying well; its better to deal with known unknowns then with unknown unknowns. 328 00:35:27,600 --> 00:35:31,440 He was bad at all of them by the way, yeah right. 329 00:35:33,100 --> 00:35:38,860 So the unknown unknowns are stuff that you lose and you don't know that you have lost it. 330 00:35:38,860 --> 00:35:45,380 If you throw something in a blackhole for all practical purposes, you have lost it, you have lost the information 331 00:35:46,040 --> 00:35:52,000 But what we are talking about exactly that, we know that we lost it, again, I don't remember what I ate for 332 00:35:52,000 --> 00:35:56,460 breakfast yesterday but I knew I had breakfast, so at least I know how much information I have lost 333 00:35:57,140 --> 00:36:06,340 by having a bad memory and so the fact that we quantify, how much information is in the blackhole and 334 00:36:06,400 --> 00:36:14,080 that its measured by the area. That turns out to be surprisingly, the key insight. So knowing how to quantify 335 00:36:14,080 --> 00:36:19,640 if you don't know is a deep principle. 336 00:36:19,640 --> 00:36:25,980 Alright, I think, yeah that's actually starting to work for me, lets forget your slide Rapheal for the moment, 337 00:36:27,020 --> 00:36:34,020 if you don't mind and go to Leonard slide, which really gets us from this idea of; there is a bunch of information 338 00:36:34,020 --> 00:36:38,780 and its maps into something that we might think of as a three dimensional image 339 00:36:38,780 --> 00:36:42,600 Victoria can you put Leonard's first slide up; Ok, what is this here? 340 00:36:43,880 --> 00:36:54,020 That's a microscopic picture of the film of a hologram which in fact I made up myself with Microsoft paint, 341 00:36:54,020 --> 00:36:59,520 so its a fake. But its about what it would look like. its about what if you look through the microscope 342 00:37:00,080 --> 00:37:06,560 at the film, not this thing that is being described by the hologram but by the piece of film itself, 343 00:37:06,900 --> 00:37:12,980 it would approximately like that. And so then if you put light through it in some particular way 344 00:37:12,980 --> 00:37:18,980 Lets us sort this first, Its got some information in in it. Its all scrambled. Its impossibly scrambled you can't look at 345 00:37:18,980 --> 00:37:23,980 this and see what it is. Anybody any guesses; what the image is there? 346 00:37:24,560 --> 00:37:29,620 Anybody want to guess... What? Leonard Susskind ... good 347 00:37:30,480 --> 00:37:38,780 I think guess down here. Ok great so - It is a fake 348 00:37:39,120 --> 00:37:44,740 Anyone see puppy, Anyone see pup, Little Horsey No, no horses. Ok Alright; lets see 349 00:37:44,740 --> 00:37:49,360 Ok, going through this next one. -Lets go to next, here is it; stand by folks 350 00:37:49,360 --> 00:37:52,880 This is another fake, I also drew that myself Alright - alright 351 00:37:53,000 --> 00:37:59,440 So if you do the right thing with hologram, namely shine light on it and so forth. It will reconstruct an image. 352 00:37:59,440 --> 00:38:06,060 So you got the flash light, may be this is obvious with flash light going through the film and somehow 353 00:38:06,580 --> 00:38:12,800 the information in the film recreates the 3D image of the clown, smoking the segar. Right 354 00:38:12,800 --> 00:38:19,780 But the interesting thing about it is; that the clown is three dimension,you can go behind it, you can see if there is 355 00:38:19,780 --> 00:38:23,420 hairs on the back of his head, you can go underneath, under the chin and beneath. 356 00:38:23,940 --> 00:38:30,540 In fact if this hologram had been made, not with ordinary light but if its been made by NMR scan. 357 00:38:30,780 --> 00:38:37,780 You could have coded on that boundary, on that surface you could have the interiors, you could have all your 358 00:38:37,980 --> 00:38:44,980 guts and blood and everything else bones, the entire full three dimensional structure would have been mapped. 359 00:38:44,980 --> 00:38:49,580 You used the word "map" and its a good word. Mapped onto the boundary, on to the film and 360 00:38:50,000 --> 00:38:57,000 the important thing is; not that you shine light to reconstruct it but that the information about the clown 361 00:38:57,240 --> 00:39:03,400 is equally well and in fact in some sense better described, more accurately described, more 362 00:39:04,440 --> 00:39:10,920 preciously described by the little dots and dashes and structures that are entirely scrambled, 363 00:39:12,340 --> 00:39:19,340 totally impossible for you to just look at, but its there, its there in that film. Its there and as you say; you can add 364 00:39:19,940 --> 00:39:24,820 detail to that informational film infinitely or is there an upper limit? 365 00:39:25,120 --> 00:39:33,040 Ok, so in the world that we are talking about which is the real world, there is a limit, no more than one bit, 366 00:39:33,660 --> 00:39:42,380 and that mean + or -, one little dot per Planck area, a Plank area is a certain unit of area that's made up out of 367 00:39:42,460 --> 00:39:50,480 the fundamental constants of nature. Its happens to be about 10^-33 cm on a side. its far smaller than anything 368 00:39:50,480 --> 00:39:55,280 that Physics studied experimentally. But no more; Where did it go? disappeared .. 369 00:39:55,900 --> 00:39:59,740 Blackholes or something like that - Yeah it went into the blackhole 370 00:40:00,220 --> 00:40:08,520 No more than one bit, that means a black dot or a white dot per Planck area. that's just information 371 00:40:08,520 --> 00:40:14,700 Alright; lets us just backed up for a second. Just as you need a certain amount of resolution 372 00:40:15,220 --> 00:40:22,180 on a piece of standard film or digital CCD chip to produce an image that's recognizable of your 373 00:40:22,320 --> 00:40:30,380 lovely pets or you kids or something like that. In Physics one bit of information is a traditional bit as though; 374 00:40:30,380 --> 00:40:34,460 Yes its a yes or no question -Yes its a yes or no question, so zero one bit, 375 00:40:34,680 --> 00:40:39,980 yeah zero/one - is necessary to specify a Plank space which is 376 00:40:40,040 --> 00:40:44,500 an infinitesimal but measurable little chunk of space. 377 00:40:44,500 --> 00:40:47,980 Beyond our ability to measure it at the present; but yes. Alright! 378 00:40:49,580 --> 00:40:56,460 And so what it says, I mean in essence what its says; is this entire room; every thing that's in it, can be, 379 00:40:56,460 --> 00:41:03,120 in principle described mathematically in terms of degrees of freedom, structures on the boundaries, 380 00:41:03,120 --> 00:41:08,460 on the walls of the room with never needing more than one bit of information per Planck area. 381 00:41:08,460 --> 00:41:14,640 That was very radical, that was very surprising because people always associated information with volume. 382 00:41:15,360 --> 00:41:18,040 We have another picture but; may be one for a round. 383 00:41:18,040 --> 00:41:22,080 Well lets go; No; lets go to; this is the pixel. The pixels in the voxels. 384 00:41:22,080 --> 00:41:25,800 Ok, let do the pixels voxels, lets think two slides - lets do Vox first 385 00:41:25,800 --> 00:41:31,480 First the pixels are artisan, alright, obviously a 2D -Can we jump, can we jump to the other one first 386 00:41:31,480 --> 00:41:34,600 Alright; we will see the voxels first Ok, - Alright! 387 00:41:34,600 --> 00:41:40,460 There is the room, if you like, there is the room and I am gonna describe the room, everything that's in the room, 388 00:41:40,660 --> 00:41:47,660 like dividing it up into the little tiny cells, lets say no bigger than atom. And what can we ask about a cell? 389 00:41:47,660 --> 00:41:50,000 We can ask; is their or isn't there an atom in it? 390 00:41:50,000 --> 00:41:52,680 Of course we can ask what type of atom but lets ignore that. 391 00:41:52,680 --> 00:41:57,160 Is their or isn't there an atom in it? and if we don't have to worry about type of an atom, 392 00:41:57,160 --> 00:42:00,720 that would be a complete description of everything that's in the room. 393 00:42:01,260 --> 00:42:08,520 And so there would be one decision for each Voxel, "Voxel" is a word that means a little cube there would be 394 00:42:08,560 --> 00:42:12,720 one bit of information per Voxel. Its either empty or its full. 395 00:42:12,780 --> 00:42:19,860 Alright; so lets divide up this room in each Plank space. -I was talking about atoms but yes; 396 00:42:19,860 --> 00:42:24,900 Oh I forgot; well in each bigger than Plank space we decided to choose; we are asking a question, 397 00:42:24,900 --> 00:42:29,980 is there an atom in their? and its Yes or No answer to that, and we will reconstruct the entire space 398 00:42:29,980 --> 00:42:35,060 in information terms in a cube like this. - Right; and we got some place still around them some 399 00:42:35,060 --> 00:42:38,640 place just not, I would say probably a lot of Yeses, right? 400 00:42:38,640 --> 00:42:41,260 No; many more Noes than Yeses; -You think? 401 00:42:41,260 --> 00:42:43,520 Oh yeah; room is empty - Yeah its just space mostly empty 402 00:42:43,520 --> 00:42:47,040 Yeah; room is almost all empty space - Yeah its always; its noisy, you hear that always but 403 00:42:47,060 --> 00:42:54,200 yeah, anyway Ok, so now that's the 3D, so whats the other picture? 404 00:42:54,380 --> 00:43:02,740 Well; what we found in essence, is that's too much information, no room can ever have as much information 405 00:43:02,740 --> 00:43:08,140 as is implicit in this picture here. The amount of information that it takes to describe the room 406 00:43:08,260 --> 00:43:14,800 is more like this picture here, one bit of information per surface area. 407 00:43:14,920 --> 00:43:21,480 So I like to say that world is "Pixelated" not "Voxelated" The world is made up or degrees of freedom 408 00:43:21,480 --> 00:43:27,140 of the the world; most accurate description we can ever have is in terms of the number of degrees of freedom 409 00:43:27,140 --> 00:43:32,680 which is proportional to the area not the volume. So its actually the reverse of our intuition 410 00:43:33,100 --> 00:43:40,620 and Gerard't, help me out here, so we like to think of gosh; you know, movie are grate but wouldn't it be 411 00:43:40,660 --> 00:43:45,080 fabulous to have IMAX 3D, in fact what Physics says is; 412 00:43:45,100 --> 00:43:52,200 You can get all the information in your 3D High Res reality world on a 2D surface. 413 00:43:52,360 --> 00:43:59,240 Let me just; one thing before I wanna let these guys to answer; the only thing is that the two dimensional 414 00:43:59,280 --> 00:44:06,280 description is gonna be monstrously scrambled, very difficult to decode, very difficult to see what's its 415 00:44:08,720 --> 00:44:14,480 a picture of, That's the cost of coding information in two dimension instead of three. 416 00:44:16,880 --> 00:44:23,800 As a mathematician your first reaction will be; there is much less space of a two dimensional surface 417 00:44:24,040 --> 00:44:30,580 in any three dimensional world. So your first reaction is; that can't be right, we will be missing enormous 418 00:44:30,640 --> 00:44:35,240 amounts of information if we try to put or scram everything on a surface, for that we have to remember; 419 00:44:38,040 --> 00:44:44,920 this is a Planck length which is extremely small to; for all standards. 10^−33 cm is extremely tiny even 420 00:44:44,980 --> 00:44:51,540 in units of elementary particles. So even this looks at first sight to be very little information, 421 00:44:51,540 --> 00:44:56,260 actually it is enormous, its gigantic. But on other hand we have to realize; 422 00:44:56,780 --> 00:45:03,020 that not only what's in this room could be mapped on a surface but entire universe can be mapped 423 00:45:03,120 --> 00:45:11,760 on the surface, that's even more gigantically crazy because you think that the surface of universe 424 00:45:11,760 --> 00:45:16,700 would be much smaller than its volume but again this Planck units are so small; 425 00:45:16,700 --> 00:45:23,580 its still have enough information on the surface to specify everything that goes on in universe. 426 00:45:23,580 --> 00:45:29,200 Well; I mean its so counter intuitive, I mean every time I go into the hall in town hall, I wonder how all of Newyork 427 00:45:29,200 --> 00:45:35,280 could fit in here. But in fact that's kind of what you are saying. So it is very very counter intuitive. 428 00:45:36,560 --> 00:45:43,560 So you come up with these mathematical conclusions that are very robust and sound and you can defend them, 429 00:45:43,560 --> 00:45:48,580 I mean do you go back; Herman, to Hawking and does he say; sorry about saying rubbish 430 00:45:48,580 --> 00:45:51,660 or I guess; I was wrong about the rubbish. 431 00:45:51,720 --> 00:45:57,920 To his credit; he has thought of changing at least his opinion and he accepts lot of these ideas. 432 00:45:57,920 --> 00:46:03,160 Einstein for example; had much harder time accepting quantum mechanics; I don't think he ever did. 433 00:46:03,800 --> 00:46:14,100 But Hawking; I think, he realize at the time when he was putting this paradox forward that by stating 434 00:46:15,380 --> 00:46:21,700 the contradiction that was in blackhole Physics, he realize that was a way of making progress. 435 00:46:21,700 --> 00:46:26,140 And of course he liked annoying his colleagues which is sort of what he was doing by making 436 00:46:26,300 --> 00:46:35,100 this particular claim. But he put us to work; so and then; by the time that answers came forward, he has; 437 00:46:35,100 --> 00:46:41,420 so he had this bet with one his colleagues that I think it was for a year long subscription to playboy 438 00:46:41,520 --> 00:46:46,160 but in the end; the colleagues decided to give him a nice book instead. 439 00:46:47,160 --> 00:46:57,420 Because the bet was settled, and then Hawking admitted that information was there; so that's it. 440 00:46:57,440 --> 00:47:06,720 Well the whole 2D/3D thing if you bring playboy into its a whole that; I know; that's a whole other information space 441 00:47:06,720 --> 00:47:08,320 - I don't wanna think about it. 442 00:47:08,540 --> 00:47:15,260 As a much younger researcher Raphael! what excites you about the holographic principle in terms of; 443 00:47:15,900 --> 00:47:24,120 and we gonna do its controversy in a moment, in terms of; what it begins to explain about other problems in Physics. 444 00:47:24,500 --> 00:47:31,160 I thinks what exciting to me is that; the only way that information could possibly not be lost when 445 00:47:31,160 --> 00:47:38,880 a black hole forms and then evaporates; was for there to be a completely universal relation between 446 00:47:38,880 --> 00:47:44,620 the information content of a region and its surface area, in other words; there was a relation between 447 00:47:45,440 --> 00:47:52,440 surfaces in spacetime which are described by gravity theory, that's the realm of Einstein general relativity; 448 00:47:52,660 --> 00:47:59,220 surfaces surrounding certain regions; those surfaces; their area specify how much information 449 00:47:59,220 --> 00:48:04,200 could be in the region that was enclosed by them. That turned out to be not the quite the right way of 450 00:48:04,200 --> 00:48:09,880 stating it but that was necessary; if information was not going to be lost in blackholes. 451 00:48:09,880 --> 00:48:14,680 In other words it led to the statement about; how much information there is in the world. 452 00:48:14,680 --> 00:48:21,640 That was completely independent of what you was using to encode the information, it didn't matter whether you 453 00:48:21,640 --> 00:48:30,840 used letters on a page or atoms, or strings, or quarks, what ever your favorite Physical ingredient was. 454 00:48:30,840 --> 00:48:36,100 It was a statement that was completely universal, if information was preserved then we were learning 455 00:48:36,100 --> 00:48:40,220 something about fundamentally how much information there is in the world. 456 00:48:40,220 --> 00:48:45,600 Even beyond that learning that fundamental - Let me just; let me say one thing just to put an accord 457 00:48:45,600 --> 00:48:52,300 Its actually not very difficult to understand why this is so; very roughly speaking any place like this room can be 458 00:48:52,300 --> 00:48:59,060 converted by crashing some shells of matter into it, into a blackhole that has the same surface area, as this room, 459 00:48:59,060 --> 00:49:04,240 and we know how much information the blackhole contains. So if information is not lost; 460 00:49:04,240 --> 00:49:08,940 that's means that information in this room; no matter what was here; had to be less to start with 461 00:49:08,940 --> 00:49:14,880 than the information of the blackhole or it most equally much and so; its completely universal. 462 00:49:14,880 --> 00:49:18,840 You don't have to know what we are made of, You don't have to know what the fundamental bits and pieces 463 00:49:18,840 --> 00:49:23,980 of Physics are, you already know how much information there is. And so its is a deep relation between 464 00:49:23,980 --> 00:49:27,780 the two things that we don't know how how to put together, Gravity and Quantum mechanics. 465 00:49:27,780 --> 00:49:31,960 Quantum mechanics is about information and gravity is about geometry and surfaces. 466 00:49:32,580 --> 00:49:41,960 But is it true or is it a distortion to say; and again for me; for a moment here; the idea of going to the blackhole 467 00:49:42,040 --> 00:49:49,040 Seems to confuse the issue because; the blackhole is interesting; because the way Hawking described it, 468 00:49:49,040 --> 00:49:53,920 information would be destroyed, that produces the controversy, which create/poses the question alright. 469 00:49:53,920 --> 00:49:57,520 What is the relation ship between the information and all of the universe. 470 00:49:57,620 --> 00:50:04,940 That is exactly why it was one of those questions where; you know; people were just asking incredibly interesting 471 00:50:04,940 --> 00:50:10,500 questions and as a consequence of resolving it, stumble upon something which was much more general 472 00:50:10,500 --> 00:50:15,980 and didn't really just holding this particular context of the blackhole, At the end you can throw the blackhole 473 00:50:15,980 --> 00:50:18,320 away just left with Alright! because I don't think most of people in this 474 00:50:18,320 --> 00:50:22,680 room; you know; encounters with blackholes are; you know; monthly at best. 475 00:50:23,300 --> 00:50:33,520 So lets just say because of the balckhole, thought experiment, controversy, argument with Hawking; 476 00:50:34,240 --> 00:50:43,240 we have stumbled upon or discovered or now see that; a fundamental feature of the universe is that; 477 00:50:44,740 --> 00:50:50,680 a two dimensional space of information specifies everything in our universe. 478 00:50:50,680 --> 00:50:55,480 something like that, it has to that. Well; initially it was clear; how to apply this 479 00:50:55,480 --> 00:51:01,740 to the whole universe. Again the context in which it was discovered was a very specific one where; 480 00:51:01,740 --> 00:51:06,580 you are for away; you throw some elephants into a small region, they form a blackhole and then evaporates. 481 00:51:06,580 --> 00:51:11,000 and you want to ask the question by looking at this Hawking radiation that came up; can I figure out 482 00:51:11,000 --> 00:51:17,320 if it was elephants or zebras that made the blackhole. Now that was resolved I think by now; pretty definitely. 483 00:51:17,600 --> 00:51:24,600 We can look at this; but our universe is nothing like that, our universe is not like the black hole, our universe is 484 00:51:24,600 --> 00:51:29,020 not a place where you can go far away, and study Hawking radiation coming out. 485 00:51:29,020 --> 00:51:34,100 And nevertheless it turned out to be true that; this was just a tip of the iceberg. 486 00:51:34,140 --> 00:51:40,180 There is completely universal relation between information and area of surfaces. 487 00:51:40,180 --> 00:51:46,940 At first it seems like that can't possibly be true, for example: if you don't take the view point of the person 488 00:51:46,940 --> 00:51:52,140 who waits for the Hawking radiation to fizzle out of the blackhole and then looks carefully at the information 489 00:51:52,140 --> 00:51:57,320 that is in it. Suppose that I fell in with the other things or with the star that was collapsing in, 490 00:51:57,720 --> 00:52:03,160 well that star have some information in it; as its collapsing to form a blackhole. 491 00:52:04,140 --> 00:52:11,140 That information can't disappear, we know from solving the Einstein equations that the surface area of the star 492 00:52:12,080 --> 00:52:18,560 become smaller and smaller and smaller until its zero at the very end when it hits the singularity 493 00:52:18,560 --> 00:52:25,020 inside a blackhole. So it seems clear that the amount of information of the star; whatever it is; at some point 494 00:52:25,020 --> 00:52:29,540 its going to become larger than this smaller and smaller and smaller surface area of the star. It gets more 495 00:52:29,540 --> 00:52:34,260 more compressed deep inside the blackhole. So then this mean that; this was just some fluke at it, 496 00:52:34,260 --> 00:52:39,480 something that applies to particular; you know; observed who live far outside a blackhole. And there is actually 497 00:52:39,480 --> 00:52:42,720 no general relation between information and surface areas. 498 00:52:42,720 --> 00:52:49,260 Well turns out No, if you state the relation in just the right way then its too even deep inside the blackhole 499 00:52:49,260 --> 00:52:55,000 or in the regions of the universe to the very large, the way you have to state it is actually in much 500 00:52:55,000 --> 00:53:00,460 more Physical way, as of saying; how much information do I have in this instant of time when my star 501 00:53:00,460 --> 00:53:06,900 is really small and has very small service area, how much is still inside the star. You have to ask; 502 00:53:08,660 --> 00:53:15,660 well; if I took a picture of that star at this time, just before its got completely crunch into a singular place 503 00:53:18,300 --> 00:53:24,220 in spacetime. If I took a picture of it how much of the star would I see. And it turns out that 504 00:53:24,600 --> 00:53:30,600 You don't have enough time, the light doesn't have enough time to traversed the whole star 505 00:53:30,600 --> 00:53:36,000 before everything gets crunched into the singularity and the game is over. You have to actually calculate this, 506 00:53:36,000 --> 00:53:39,800 You have to take my word for it right now, but - I am taking you word for so much 507 00:53:40,180 --> 00:53:46,820 But the point is; if you ask, what can actual light ray see? How much information can they see? - Right 508 00:53:46,820 --> 00:53:51,660 light ray that comes out the area in question and it makes absolutely no difference what area you pick, 509 00:53:51,660 --> 00:53:54,200 anywhere in the universe, any shape, doesn't even have to be closed. 510 00:53:55,180 --> 00:54:02,180 What those light ray see is some piece of the star in this particular example, as by some conspiratorial miracle 511 00:54:02,180 --> 00:54:06,740 its always less information in that piece o the star than the surface area you started from. 512 00:54:06,740 --> 00:54:10,740 Its a much bigger conspiracy of which only a sort of 513 00:54:10,740 --> 00:54:14,240 tip of the iceberg was discovered in the context of blackhole. 514 00:54:14,240 --> 00:54:19,380 Well; its a little bit like uncertainty in the sense that if you try to measure you only gonna get a piece of it 515 00:54:19,840 --> 00:54:26,560 but that doesn't effect the existence of all the information. Its all there, the fact you can't get it 516 00:54:26,560 --> 00:54:30,840 or don't have big enough camera is your own personal psychological problem, 517 00:54:30,840 --> 00:54:31,880 It doesn't effect the universe at all 518 00:54:31,880 --> 00:54:38,500 Well; indeed if you wanted to ask how much information is there in the universe than again its actually very 519 00:54:38,500 --> 00:54:44,460 useful that the information is sort of coded on region that are seen by light rays, You can just ask, 520 00:54:44,680 --> 00:54:51,160 well; what is in our past, what is in the region from which light could have reached us up until now, 521 00:54:51,160 --> 00:54:56,200 and that region is bounded by basically the light rays that are just barely making it to you eyes right now, 522 00:54:56,200 --> 00:55:01,320 and have been traveling for billions of years since the beginning of the universe. And those light rays; 523 00:55:01,320 --> 00:55:06,600 well; if you follow them back, of course they come from larger and larger region as you follow them back 524 00:55:06,600 --> 00:55:12,020 that's farther and farther away. But at some point there is surface area actually become very small again; 525 00:55:12,020 --> 00:55:15,840 when you follow them all the way back to the bigbang, because every thing is small at the bigbang. 526 00:55:15,840 --> 00:55:20,220 Universe is basically contracting to the single point at that point. 527 00:55:20,220 --> 00:55:24,280 So there is a largest area which tells you how much information there is in the Universe, 528 00:55:24,280 --> 00:55:28,940 some where between the bigbang and us, that is span by these light rays. 529 00:55:28,940 --> 00:55:32,940 So we can see exactly what the maximum amount of information there is. 530 00:55:32,940 --> 00:55:39,120 So is it; the case on some level that the function of our senses, I mean as; you know; Galileo looked at light rays 531 00:55:39,500 --> 00:55:47,180 and drew some conclusion about the Universe, are tiny; sort of; instances of the Universe conveying information, 532 00:55:47,180 --> 00:55:53,180 some thing that's much bigger that we are now extrapolating to extreme states of the Universe, 533 00:55:53,180 --> 00:55:58,500 either in terms of the very beginning to time with the bigbang or; the sort of; end of matter in a blackhole, 534 00:55:58,560 --> 00:56:01,520 that they are part of same story a little bit? 535 00:56:01,520 --> 00:56:07,420 Well, the interesting thing about the holographic principle, I think all of us probably agree on this is that 536 00:56:07,420 --> 00:56:11,580 Its a statement that can be made in a situation where we think we understand Physics very well. 537 00:56:13,280 --> 00:56:20,240 The area that describe how much information there is in the Universe that we see, is not an area that lives 538 00:56:20,240 --> 00:56:24,860 somewhere very close to bigbang where we might not trust our equations. The area that tells us 539 00:56:24,860 --> 00:56:29,320 how much information there is inside of a blackhole is not an area that's somehow close to the singularity 540 00:56:29,320 --> 00:56:32,760 inside the blackhole, which we don't understand as well as we would like to. 541 00:56:32,760 --> 00:56:38,080 These are areas in region of space time that are arbitrarily well understood. They are completely 542 00:56:38,080 --> 00:56:42,800 harmless. there; you know; Einstien theory implies harmless is good - harmless is always good 543 00:56:42,800 --> 00:56:48,420 I mean; I still wouldn't jump into the blackhole but they are very; you know; well understood. 544 00:56:48,560 --> 00:56:54,320 The whole statement takes place in a regime of Physics that we completely understand. 545 00:56:54,320 --> 00:57:00,660 But what we don't understand ultimately is why it is true, It seems like a conspiracy. Every time you check 546 00:57:01,540 --> 00:57:08,540 it works out. And I think that by itself; I think; was a huge piece of support for the idea that information isn't lost. 547 00:57:08,540 --> 00:57:12,940 All these miracles happen for information not to get lost. It would be funny, if it was at the end 548 00:57:13,000 --> 00:57:18,440 But you have me do the case - Funny yeah - HAHAHA -- HAHA -funny - 549 00:57:18,440 --> 00:57:23,080 -Your sense of humor is not useful to find - Oh I know, yeah Alright, well I love to talk lapses like the next guy but 550 00:57:24,400 --> 00:57:31,360 So Herman! what is the counter argument here, I mean; I got two questions; one is: what is the counter argument 551 00:57:31,360 --> 00:57:39,300 Who persists with the idea that this holographic principle may be fun to talk about but in fact doesn't really help us 552 00:57:39,440 --> 00:57:45,200 or there is another explanation I would necessary say that it might be that people have 553 00:57:45,200 --> 00:57:51,940 counter argument but right now you can state it as a principle because we have indications that its there 554 00:57:52,720 --> 00:58:00,000 but again; its basically still from intuitive point of view its absurd that this would be true 555 00:58:00,000 --> 00:58:06,200 Because again; if we wanna describe what's going on for sure we going to tell Ok, well some thing is happening 556 00:58:06,200 --> 00:58:11,140 Here at a given time or something is happening there, so essentially the information that you use 557 00:58:11,960 --> 00:58:18,680 to describe things, for sure grows with the volume. And indeed the equations we are using to describe 558 00:58:21,400 --> 00:58:27,800 physics and it have all those properties. So right now we don't have a real way of understanding; 559 00:58:27,880 --> 00:58:32,900 how this is really true, so we know, we have hints that its true 560 00:58:32,900 --> 00:58:38,340 -There is no evidence. No we don't have a mathematical theory that preciously describe; how it is. 561 00:58:39,180 --> 00:58:46,140 We have strong evidence that its true, and I think; sort of early time say; early 90s; where, if you would; 562 00:58:46,140 --> 00:58:52,700 and I think; it was conference in the early 90s where there was a vote, Ok, how many people were believe in 563 00:58:52,700 --> 00:58:57,900 that the information was lost , and then more than half of the hands went up, and it was very small group of 564 00:58:57,900 --> 00:59:03,840 people that saying; well we don't believe that information is lost and there was only a couple of people 565 00:59:03,840 --> 00:59:07,140 -and couple of "rubbish" group And there was yeah the "rubbish" group and then 566 00:59:07,140 --> 00:59:11,800 there was the "OK" group Right! and now the "rubbish" group is bigger, its almost 567 00:59:11,800 --> 00:59:15,000 the whole room - yeah if you call us the "rubbish" group 568 00:59:15,000 --> 00:59:19,580 -Well, you were then, you were then Yeah we were called "rubbish" yeah its correct 569 00:59:20,000 --> 00:59:24,480 and proudly so -and how; I wanna go back to this information and I 570 00:59:24,480 --> 00:59:28,740 actually want you to go through those slides that I have seen before, which I think are fascinating but 571 00:59:28,780 --> 00:59:41,380 Gerard't! let me ask you, is information a particle in the sense that its like matter, its information a kin to being 572 00:59:41,500 --> 00:59:49,200 like a electrons, protons, quarks, antimatter. Is it some sort of parallel phenomenon that's goes along with 573 00:59:49,200 --> 00:59:51,420 reality or just something fundamentally different? 574 00:59:52,580 --> 00:59:58,940 No actually I think its about time that we try to disagree with each other, and 575 00:59:58,940 --> 01:00:01,200 -No And so I want to; no you don't 576 01:00:02,740 --> 01:00:07,620 -Starting to get good Because I want to bring in a notion which hasn't been 577 01:00:07,820 --> 01:00:13,480 put forward yet. The question of dynamics; you know when I first saw 578 01:00:13,500 --> 01:00:20,920 people windsurfing, I love to also to go windsurfing, so on one day I thought I am theoretical physicist, 579 01:00:21,040 --> 01:00:29,040 I can work out how to stand on the board, how to hold saill without falling over and I worked it all out, 580 01:00:29,080 --> 01:00:35,560 and stood on the board, I could have the sail, and i didn't fall over and I went any direction I want, 581 01:00:35,560 --> 01:00:41,500 except I only solved the static problem, I didn't solved for what happens if a big wave comes. 582 01:00:41,600 --> 01:00:48,320 And what you have to do is you want to make a sudden turn, this I never solved so when ever that happened, 583 01:00:48,320 --> 01:00:52,240 I fell over. Now here the problem is same, so far we have been 584 01:00:52,240 --> 01:00:59,220 discussing this static question, what is information, where is it, and so on. You can discuss it at length, 585 01:00:59,700 --> 01:01:07,500 but there is something else in physics, the dynamical question; how things evolve in time and how we phrase 586 01:01:07,600 --> 01:01:12,540 laws of nature. And new we encountered a deep and fundamental problem. 587 01:01:13,100 --> 01:01:20,700 Which is; the world look to us three dimensional, if I make a disturbance here like saying something or 588 01:01:20,900 --> 01:01:28,840 I am shining a light, the disturbance moves with speed of light or slower to its environment and it never goes 589 01:01:28,880 --> 01:01:34,840 faster than speed of light from here to a point far away in Universe. That is a fundamental three dimensional 590 01:01:34,960 --> 01:01:41,960 property of the world as we know. And it is been tested very very accurately in all branches of Physics 591 01:01:41,960 --> 01:01:48,740 Very fundamental principle, not only that disturbances move with certain maximum speed also causality. 592 01:01:48,960 --> 01:01:55,660 That is; when ever you cause some disturbance somewhere it effect never goes faster than 593 01:01:55,660 --> 01:02:01,660 speed of light and certainly doesn't go back in time Now this principle we would like to keep 594 01:02:01,780 --> 01:02:07,020 and now holography is standing in our way, its not doing the thing we want. 595 01:02:07,460 --> 01:02:14,460 If my friend then here, is right; and information on the two dimensional surface is completely scrambled, 596 01:02:14,460 --> 01:02:20,080 how did you explain; if you made a disturbance here, the disturbance doesn't spread faster than speed of light. 597 01:02:20,360 --> 01:02:28,900 How would Leia, when she moves arms in the hologram, how come that these disturbances don't moves faster 598 01:02:28,900 --> 01:02:34,740 than a given speed in her hologram. There's still something basically wrong with the idea. 599 01:02:34,740 --> 01:02:39,540 And that be -Why would they have to move faster than the speed of light to work? 600 01:02:39,820 --> 01:02:46,880 That's relativity theory and relativity theory works extremely well, we don't want to give that up too easily 601 01:02:47,780 --> 01:02:54,780 as a fundamental principle, after all relativity was also a principle that went-ed to Stephen Hawking's derivations 602 01:02:54,780 --> 01:02:58,240 If you throw it away, you are trowing away blackholes as well. 603 01:02:58,920 --> 01:03:06,660 So life isn't that easy, there's a problem here. So how do we address that and then 604 01:03:06,660 --> 01:03:13,100 I am coming back to quantum mechanics, say well; we use quantum mechanics from the beginning until 605 01:03:13,100 --> 01:03:19,160 the end. There's something not quite right about the quantum mechanics, and I am been thinking a lot 606 01:03:19,720 --> 01:03:27,200 last decades basically about; there must be something underneath quantum mechanics, some more basic 607 01:03:27,200 --> 01:03:34,000 mechanical system that explains why the world that we encounter today looks like quantum mechanical. 608 01:03:34,500 --> 01:03:40,380 That could solve this problem. Because it could be that in a pre-quantum world, 609 01:03:40,380 --> 01:03:45,400 the world is three dimensional. Information gets lost all the time 610 01:03:45,780 --> 01:03:54,220 In fact a suspicion I have; might practically only one in Universe today that has a suspicion that there's 611 01:03:54,280 --> 01:04:02,440 underline theory in which information gets lost, to such an extent that if you have a bulk of material somewhere, 612 01:04:02,440 --> 01:04:07,700 so much information gets lost, that the only thing you can retain is what sits on the surface. 613 01:04:08,340 --> 01:04:14,580 And that's the reason why; information wise; you have such a thing as holographic principle. 614 01:04:14,580 --> 01:04:20,220 The only amount of information that you can keep; if you have a bucket of water; is what sits on the edge 615 01:04:20,220 --> 01:04:24,360 of the bucket of water. Whats happens to be inside will eventually get lost. 616 01:04:24,360 --> 01:04:30,420 Not according to quantum theory because we just realized all quantum theory preserves the information 617 01:04:30,560 --> 01:04:35,280 But it may be a pre-quantum theory in which this information gets lost. 618 01:04:35,280 --> 01:04:37,760 -Now this is it, let me to say This pre-quantum theory it could be three dimensional 619 01:04:37,840 --> 01:04:42,820 and then we might possibly find a resolution of this problem. 620 01:04:42,880 --> 01:04:51,020 So is pre-quantum theory, something that happened before the bigbang or its pre-quantum theory; 621 01:04:51,020 --> 01:04:54,340 something that happens before you learned like - I mean pre-quantum in a logical sense 622 01:04:54,380 --> 01:05:01,380 It is that some thing, that some fundamental principle lying underneath, the principle of quantum mechanics 623 01:05:01,400 --> 01:05:05,800 -I see Say we have molecules, we have atoms, we have things 624 01:05:05,800 --> 01:05:11,340 smaller than atoms but smaller than that are things which might not be quantum mechanical. 625 01:05:11,680 --> 01:05:20,320 That is my premature explanation as how to reconcile the idea that the three dimensional world 626 01:05:20,320 --> 01:05:27,000 seems to be two dimensional by holographic principle, yet there is causality in the three dimensional sense. 627 01:05:27,000 --> 01:05:30,640 This is a problem that has not yet been properly addressed 628 01:05:30,680 --> 01:05:36,160 and I think something should be done about this. If we dont, we will never 629 01:05:36,160 --> 01:05:37,120 -Yeah get to work, 630 01:05:37,120 --> 01:05:42,280 If we dont, right, if we will never get useful theory - forget homelessness guys come on 631 01:05:42,280 --> 01:05:44,220 powerful enough for the small distances. 632 01:05:44,240 --> 01:05:54,060 Well lets; put that to Leonard! is there a possibility of a pre; you know; a more axiomatic kind of pre-quantum 633 01:05:54,060 --> 01:05:58,720 Its a question of axiomatic Alright, but then in some sort of more basic state than quantum mechanics 634 01:05:58,760 --> 01:06:04,460 The answer is that; I don't know What you're seeing here is an interesting thing 635 01:06:05,760 --> 01:06:12,760 First of all I would say that it should be clear that this whole holographic story is the most radical thing 636 01:06:13,300 --> 01:06:20,300 that has happened to our understanding of spacetime, matter. Since the invention of quantum mechanics and relativity 637 01:06:21,100 --> 01:06:28,100 It is really some thing very very different. Where is it going? what it is going to explain? How do we explain it. 638 01:06:31,860 --> 01:06:38,820 Well incidentally we all agree largly on what we said up till now and you'll find that Physics in general, 639 01:06:38,820 --> 01:06:44,500 probably in science in general; at any given time there are those things which have been made into established 640 01:06:44,500 --> 01:06:52,640 science, that people agree on and that subset they will tend to agree on unless there's screwballs and outside 641 01:06:52,760 --> 01:06:59,920 the mainstream of the community but then once you go past that, once you go even just a little bit past 642 01:06:59,920 --> 01:07:05,740 What we really know, you will start finding it becoming a very very human subject, subject with 643 01:07:06,540 --> 01:07:13,540 Lets put it this way, good physicists are as variable as snowflake. Every single one of them is different, 644 01:07:13,700 --> 01:07:22,680 every single one of them has a different prospective and once you go past that point where we have confirmation, 645 01:07:22,680 --> 01:07:28,740 where we do agree. you are going to find that just about everybody has a different view of where its gonna go 646 01:07:28,740 --> 01:07:33,320 Sure, that I can understand but lets focus on the radicalism; for a moment; because I think people can 647 01:07:33,320 --> 01:07:38,940 understand how relativity radically changed the Newtonian view of reality in the sense that; the 648 01:07:39,220 --> 01:07:46,220 straight lines in the Newtonian world are actually curved in certain spaces and that curvature relates to the force 649 01:07:46,320 --> 01:07:52,240 of gravity in some way and so around stars space actually bends, that's a radical notion. 650 01:07:52,240 --> 01:07:56,700 Its probably only the last thirty years that, that's been internalized to be something that kind of everybody 651 01:07:56,700 --> 01:08:02,000 understand. You can't really appreciate the Matrix, movies like the Matrix, unless you sort of understand 652 01:08:02,080 --> 01:08:09,980 the sort of relativistic world. How does this notion produce a radical change; 653 01:08:10,400 --> 01:08:16,400 in the way; that we might see relativity I think it still work in progress and we don't know. 654 01:08:18,140 --> 01:08:24,540 Gerard't has his view, I have my view, Herman has his view, whats his name over there, has his view 655 01:08:29,940 --> 01:08:36,660 And but I tell you if you go out it'll come to you. You go two blocks outside of this room, there's a lot of 656 01:08:36,660 --> 01:08:39,360 people who have no view a lot of people who have no view 657 01:08:39,880 --> 01:08:45,160 -Yeah absolutely no view My own view is not all that different than my colleague 658 01:08:45,160 --> 01:08:48,740 over here Its not that I think this is going to be the some 659 01:08:48,740 --> 01:08:52,020 deterministic theory that gonna underline quantum mechanics 660 01:08:52,020 --> 01:08:58,360 I think its going to inform how we think about quantum mechanics very deeply and its gonna change 661 01:08:58,360 --> 01:09:02,080 in an enormously big way that we think about quantum mechanics. 662 01:09:03,060 --> 01:09:09,460 That I am sure of, whether it will be the way that, Raphael and I have proposed over the last couple 663 01:09:10,320 --> 01:09:15,360 of weeks, on the way, that Hooft has proposed for years. Herman has his ideas 664 01:09:15,360 --> 01:09:21,640 I think that remains to be seen and its a work in progress. I think there'll be progress on it, I think 665 01:09:21,640 --> 01:09:27,660 when we come back here; may be not next year but five years from now, there'll be more knowledge. 666 01:09:27,860 --> 01:09:34,280 But its very clear; we are on the cutting edge of an and on the cusp of, 667 01:09:34,280 --> 01:09:38,040 I think a major Paradigm shift; in the way; the world looks 668 01:09:38,040 --> 01:09:43,520 Alright! that's great now, how are we doing, we feeling pretty good about holographic principle and projection 669 01:09:43,520 --> 01:09:48,700 right? right and we are feeling pretty good about how information is a much more complicated thing than 670 01:09:48,800 --> 01:09:55,360 may be the concepts from our intuition right? Ok good, Here's a question that's put you on the spot, 671 01:09:55,360 --> 01:10:02,100 but its relates to your issue of; each of you think differently; the physicist are as different as snowflakes 672 01:10:02,320 --> 01:10:11,920 and hopefully they stick around longer than snowflakes. If I were to put a holographic principle T-shirt 673 01:10:12,300 --> 01:10:19,260 on each one of you that specified how each one of you represents a particular sense of whats gonna happen, 674 01:10:19,260 --> 01:10:24,860 what we are gonna discover, what aspects that represent your position. What would your T-shirt say 675 01:10:24,860 --> 01:10:29,140 I believe in holographic principle and its going to look like blank. 676 01:10:29,940 --> 01:10:36,500 I dont know I would like to have something like; I ❤ HP, or something. but that's gonna be on the back. 677 01:10:36,500 --> 01:10:40,380 The front is gonna have to more To your ticket to quantum gravity on the back, 678 01:10:40,380 --> 01:10:43,540 -Quantum so Your ticket to quantum gravity, but why do we 679 01:10:43,580 --> 01:10:49,200 call it a principle. Like you know; I think the positive spin, the most 680 01:10:49,200 --> 01:10:54,920 positive spin I can try to put on this and I am being optimistic when I say: this is; compare this to the 681 01:10:54,920 --> 01:11:00,100 equivalence principle, the equivalence principle is something that; Einstein recognized; you know; a huge 682 01:11:00,100 --> 01:11:05,860 conspiracy in nature, why do all objects fall at the same rate, you know different particles with different charges 683 01:11:05,860 --> 01:11:11,440 do not get attracted to each other at the same rate but with gravity for some reason everything 684 01:11:11,440 --> 01:11:17,240 gets attracted in exactly the same way. Amazing current conspiracy from the point of view of Newtonian theory, 685 01:11:17,240 --> 01:11:21,740 you just have to put it in by hand, doesn't to redact anything but its just crazy, it needs an explanation 686 01:11:21,740 --> 01:11:28,300 See, elevates this observation to Universal principle, you have to find a theory that makes this obvious to start 687 01:11:28,300 --> 01:11:32,780 with and that would have to be the quantum gravity because whats involved here is both quantum theory 688 01:11:32,780 --> 01:11:38,520 and general relativity, it would have to be the theory that knows about both so its clearly is a signpost, 689 01:11:39,280 --> 01:11:46,280 may be we need more signposts to find the right answer. But for You, holographic principle is a first step towards 690 01:11:46,280 --> 01:11:50,960 a theory of quantum gravity that begins to explain what's so frustrating about gravity. 691 01:11:51,760 --> 01:11:58,760 Well indeed, what Gerard't just said; tells us why its been so hard, you have to explain, where this holographic 692 01:11:58,980 --> 01:12:04,660 bound on information comes from, while not destroying; what we know about locality. 693 01:12:04,660 --> 01:12:07,940 The fact that I get to know is this part of the room, something independently 694 01:12:07,940 --> 01:12:13,060 there or I get to move particles around independently seems like you don't have to know whats over there, 695 01:12:13,120 --> 01:12:18,320 to do something here. There seems to be a conflict here between holography and 696 01:12:18,320 --> 01:12:20,560 the way that Physics has worked up until right now. 697 01:12:20,560 --> 01:12:26,440 On you T-shirt Herman, what would it say? I mentioned the movie the Matrix, probably something; 698 01:12:26,460 --> 01:12:40,640 some image like these letters and there's Neo, whats his name; the guy who; he goes and he starts flying with 699 01:12:40,640 --> 01:12:47,460 anti gravity. I think that's pretty good. So let me explain why the Matrix, we talked about sort of things; 700 01:12:47,460 --> 01:12:52,460 not being able to move faster than the speed of light. I think the people that came up with the name of 701 01:12:52,460 --> 01:12:56,720 the Matrix actually had something pretty good at mind there. Because what is a Matrix; its essentially; 702 01:12:56,720 --> 01:13:00,880 something that relates something that's here with something that's completely somewhere else; 703 01:13:03,080 --> 01:13:10,080 and so I think indeed; that's sort of the future; at least this development; will be that we start actually with 704 01:13:10,080 --> 01:13:16,260 information. So information is going to be our starting point and space-time is not something we start with. 705 01:13:17,060 --> 01:13:24,020 We forget about what space is and what time. And then somehow the information by thinking about; how much 706 01:13:24,020 --> 01:13:30,740 information is; what information is doing then the space-time; what we call be emergent, it will come out of 707 01:13:31,660 --> 01:13:38,220 just a bunch of zeroes and ones. And here is one idea that I think; actually I can put here; just since 708 01:13:38,220 --> 01:13:41,680 no one is listening and I can just say; what I want -They're listening; I guarantee you 709 01:13:42,960 --> 01:13:48,640 -There's no non-disclosure thing; so So we talked about information and I wanna know 710 01:13:48,640 --> 01:13:54,240 things; by the way; the information tends to do again, it gets lost all the time; actually that's called the second 711 01:13:54,380 --> 01:14:01,380 law of thermodynamics. The lost information we call it entropy. entropy always increases, chaos increases 712 01:14:01,800 --> 01:14:08,440 and that's a fact that's true in our Universe and its effect, that's true in other Universes as well. 713 01:14:08,440 --> 01:14:14,280 So its very fundamental fact of how things work. And whats also probably also true that; in other 714 01:14:14,360 --> 01:14:19,080 Universes is that; things indeed fall if you drop them they'll go down. 715 01:14:19,080 --> 01:14:26,560 And it seems those two facts are very closely related. The fact that information gets lost all the time 716 01:14:27,440 --> 01:14:34,320 And the fact that things fall, so I think that's -lost is different from destroyed? 717 01:14:34,780 --> 01:14:40,060 Lost; when I say lost; indeed its going to be the "known unknown" -Alright got it 718 01:14:40,540 --> 01:14:50,580 known unknown; the increase in known unknowns; that's responsible for space-time, for curvature of space-time, 719 01:14:50,580 --> 01:14:55,760 for gravity. the facts that things fall. I mean; what are you suggesting is that; you know; when 720 01:14:56,180 --> 01:15:03,180 I forgot something, I am instead of just having a kind of pre-senility moment. I am actually participating in a 721 01:15:03,180 --> 01:15:07,660 grand march of our understanding of the Universe. Right that's correct 722 01:15:08,880 --> 01:15:15,540 Yeah that's I am loving, I am glad, I came tonight Gerard't! what would be on you T-shirt or sign that would 723 01:15:15,720 --> 01:15:26,640 suggest where you fall on, and I guess probably the pre-quantum theory, the proto quantum theory that might be 724 01:15:26,640 --> 01:15:29,600 on you t-shirt. That might be the direction that you would be headed. 725 01:15:30,220 --> 01:15:39,060 I will continue to ask nasty questions and say well; you know; you can have this fancy beautiful idea 726 01:15:39,160 --> 01:15:46,160 but remember that fundamental principles on which the original idea was based that you are losing out of sight 727 01:15:46,760 --> 01:15:57,000 and so this was why; I mention causality, the fact of the order of cause and events. That is to me a very primary 728 01:15:57,460 --> 01:16:06,200 law or rule of nature. That every thing that happens here has its origin in the past; that's what we call causality. 729 01:16:06,500 --> 01:16:13,380 there's a cause of every thing happening in this world. That's how laws of nature are being formulated. 730 01:16:13,820 --> 01:16:20,820 If you don't have that; you can; for instant; go backward in time and you have circular situations in time; 731 01:16:20,820 --> 01:16:26,640 that you can go and kill you grand father if you could move back in time. That's clearly nonsense and then you 732 01:16:26,640 --> 01:16:33,340 get circular argument and you get chaos in laws of nature themselves. Nature can't solve its own equations 733 01:16:33,380 --> 01:16:38,240 that can not be right we must have the principle of causality 734 01:16:38,880 --> 01:16:46,800 Now this is somewhat at odds with this holographic principle. I don't say to die at odds but add some tangent 735 01:16:47,880 --> 01:16:54,880 here. And what we want the whole reason why we are doing this, while we making this; all these considerations; 736 01:16:54,880 --> 01:17:00,620 is that we want to have a better model, a better theory of what happens in the Physical world 737 01:17:00,620 --> 01:17:08,120 We want to explain why the particles; that you have today; behave as we have seen and studied them 738 01:17:08,120 --> 01:17:12,300 today and there are many things you understand and many things you don't understand 739 01:17:12,500 --> 01:17:20,000 We have the standard model of elementary particles; its a beautiful rigid scheme of all particles known today 740 01:17:20,000 --> 01:17:26,460 and it is marvelously precise described by this standard model but there are mysteries in it, which we want to 741 01:17:26,460 --> 01:17:32,380 understand and solve as well. we are very ambitious we've made marvelous theory of nature; its not good 742 01:17:32,380 --> 01:17:40,840 enough. We still know that blanks spot in this theory we want to fill in and this is why we doing this we want to 743 01:17:41,040 --> 01:17:46,260 find new basic principles to improve our understanding of nature, that's what all of this is about. 744 01:17:46,580 --> 01:17:53,580 But the only way to understand or to improve our understanding of nature is what; asking all sort of nasty questions 745 01:17:55,000 --> 01:17:59,800 Questions our colleagues rather not ask because they're so confusing. 746 01:18:00,180 --> 01:18:06,180 Well, lets ask confusing questions anyway; and see if we can come close to answering them. 747 01:18:06,180 --> 01:18:13,700 Any question that has an unexpected answer; might bring us, help us; go forward and make an 748 01:18:13,700 --> 01:18:19,060 improved theory of the world that we live in. Thats what the real reason is; for this exercise 749 01:18:19,800 --> 01:18:26,520 And I love this idea that possibly one way of thinking about causally and forward branch of time is as a 750 01:18:26,600 --> 01:18:38,700 information state, as a sort of a; an understanding of the march of time, as a set of information that; you know; 751 01:18:38,880 --> 01:18:44,240 one event leads to another event. Its a vision that the Universe is very much like 752 01:18:44,260 --> 01:18:52,220 information processing machine, just like your laptop or another computer. I like to view the nature as a 753 01:18:52,220 --> 01:18:58,840 gigantically big computer that has information going into it and information come out processed. 754 01:18:59,700 --> 01:19:05,940 The processors; there are laws of nature. laws of nature is; say that something happens, some 755 01:19:07,000 --> 01:19:13,480 particular configuration goes in. Its being rearranged in other combinations of data goes out. 756 01:19:13,780 --> 01:19:20,780 That's how in Physics; traditionally we consider the process of particles touching and scattering at each other. 757 01:19:21,740 --> 01:19:28,740 Two paths come like this; they hit each other and they go of the reaction. That's we call scattering process 758 01:19:28,740 --> 01:19:34,500 is an important way of describing the laws of nature. What happens when two particles meet, how do they 759 01:19:34,500 --> 01:19:39,660 separate, do they break each other up, do new particles forms, and so on so forth. 760 01:19:40,260 --> 01:19:46,500 So that's a fundamental way of phrasing laws of nature, and that's what we want to understand. 761 01:19:46,500 --> 01:19:52,440 -Can I ask you a question on this. so again; if we talk about pre-quantum mechanics, in quantum mechanics; 762 01:19:52,440 --> 01:19:57,980 we know; that at least one of the foundation of Physics; quantum mechanics has thrown it out of the window. 763 01:19:57,980 --> 01:20:02,560 Because on of the foundations of Physics; was the; if you know what's happening at a certain moment, 764 01:20:02,560 --> 01:20:08,260 what the situation is a certain time, than one step later you would know; what happens next. 765 01:20:08,840 --> 01:20:16,620 But in quantum mechanics you have completely identical situation that's a second later would give you 766 01:20:16,620 --> 01:20:19,520 two different outcomes -That is right 767 01:20:19,760 --> 01:20:25,840 Is that a principle that you accept or its your pre- quantum mechanics going to be of the type 768 01:20:25,840 --> 01:20:29,840 where you can connect. The principle I accept entirely; within the language of 769 01:20:29,840 --> 01:20:37,400 quantum mechanics, but my suspicion is; its only a suspicion; is if quantum mechanics can not be the entire 770 01:20:37,660 --> 01:20:44,660 story. There's something else happening and you are exactly asking the right question; which is how come; 771 01:20:44,660 --> 01:20:51,500 the two particles reach each other; and in the beginning they were identically same; and then suddenly they must 772 01:20:51,780 --> 01:20:58,780 do either this or it might be that or other particles might come out and all that is described by Matrix. In fact; 773 01:20:58,780 --> 01:21:04,800 in quantum mechanical sense and; but nobody knows how to predict what; which or the possibilities 774 01:21:05,140 --> 01:21:11,920 is actually being realized.That I think is a weak spot in our present understanding of quantum mechanics 775 01:21:11,920 --> 01:21:18,560 Why is it impossible to predict in advance; what will happen and there are numerous examples of this 776 01:21:18,560 --> 01:21:26,160 Which are typical for quantum mechanics and physicist today have learned to ignore the problem. to say; 777 01:21:26,340 --> 01:21:33,340 We solve everything except we cannot always predict exactly what happens. What we can say is that you need 778 01:21:33,340 --> 01:21:39,660 all the possibilities to compute what happens after that, so that's a mysterious feature of quantum mechanics. 779 01:21:39,680 --> 01:21:46,600 -And you want to embrace the mystery rather than ignore. Exactly, Ok, they've learned to do that because 780 01:21:46,600 --> 01:21:54,540 it is so successful, it works tremendously well in understanding nature. But it cannot; to my taste; 781 01:21:54,540 --> 01:22:03,040 it cannot be the entire story. There's something else happening but at a different level of nature and my belief 782 01:22:03,040 --> 01:22:12,160 is the plank scale different from the scale of elementary particles that; that could well be the level at which things 783 01:22:12,160 --> 01:22:17,960 are fundamentally different. There you have; if two things scatter, they have only one choice to make 784 01:22:18,140 --> 01:22:26,660 not very much. That's the idea of determinism, which people laugh at; when I mention this idea; people just 785 01:22:26,660 --> 01:22:32,280 manage to keep their smile away from their faces but otherwise; you know; as soon as I am away; I am sure 786 01:22:32,280 --> 01:22:36,920 they are laughing about this idea of determinism. Well; we can check some of the comments on the 787 01:22:36,920 --> 01:22:41,440 website later; I think it looks crazier dear, but well, its an old idea 788 01:22:41,480 --> 01:22:49,980 its an old idea, and its proven wrong about a million time and; but always they prove wrong; because they're 789 01:22:49,980 --> 01:22:55,180 making very conservative assumptions and I don't believe those assumptions, so I still think as a way 790 01:22:55,180 --> 01:23:00,140 -Oh nasty question That's very very difficult and its a dispute going on for 791 01:23:00,140 --> 01:23:07,020 years and years, starting all the way back with Einstein and Niels Bohr. All historians of science say Einstein 792 01:23:07,020 --> 01:23:13,420 was wrong Bohr was right, and I believe its not true. Oh nasty nasty questions fits on a t-shirt of course 793 01:23:13,420 --> 01:23:17,540 Nasty question does fit on a t-shirt, that's good Leonard! yours? 794 01:23:18,180 --> 01:23:26,500 Well; just to respect to what Gerard't says; I would't bet against what he says, on the other hand; I just can't see; 795 01:23:26,500 --> 01:23:35,360 how it will work, but its those kind of conflicts which get us where we want to go. But my t-shirt; well; if you can't 796 01:23:35,360 --> 01:23:38,400 say Brooklyn Bouguer Dodgers I guess I would like at this 797 01:23:40,100 --> 01:23:48,360 The UVIR connection, now the reason I bring that; I say that; is to give me an opportunity to explain something else 798 01:23:48,360 --> 01:23:55,020 To give me 5 more minutes to explain something else which we will probably; all agree about, but which is 799 01:23:55,020 --> 01:24:00,940 a very bizarre property of; what the nature; at least if the ideas we are talking about are correct. 800 01:24:01,560 --> 01:24:08,440 Its not totally surprising that as you try to get more and more and more accurate description of nature; 801 01:24:09,000 --> 01:24:14,520 its looks more and more scrambled. To get the best description of nature you have to 802 01:24:14,520 --> 01:24:19,840 account for all the degrees of freedom, and some times it just too much of a good thing; I mean you know; 803 01:24:19,840 --> 01:24:25,860 we know of what happens when you try to have too much information, too much information can lead 804 01:24:25,860 --> 01:24:30,180 to situation where you're just completely confused because you just live with it, 805 01:24:30,180 --> 01:24:35,600 -would it be like you take or mount a camera over the city of Newyork to put a light on everybody's head 806 01:24:35,600 --> 01:24:41,080 and over time you specify; where they go. It looks great for about 10 minutes and then its mush 807 01:24:41,400 --> 01:24:49,100 Even taking a sharp snapshot at an instant, too much information will flood you, you know we know; the CIA 808 01:24:49,100 --> 01:24:53,700 gets so much information and them it doesn't know what to do with it and it just get too much. 809 01:24:54,220 --> 01:25:02,320 Its not too surprising; you know; you'd learn much much less about a body of water with a surface and so forth; 810 01:25:02,760 --> 01:25:09,760 if I gave you a description with a table which just gave you the position and the velocity of every single 811 01:25:10,120 --> 01:25:16,040 molecule. That would be an impossible thing to deal with, so its not totally surprising. 812 01:25:16,040 --> 01:25:21,420 Windsurf on that information, yeah Its not totally surprising that the better you try to do in a 813 01:25:21,420 --> 01:25:24,820 better description, the more scramble that's going to look. 814 01:25:25,260 --> 01:25:30,300 Whats also new here is something very different than the other situations. 815 01:25:30,300 --> 01:25:36,220 In the other situations getting more and more information usually means more and more detail 816 01:25:36,220 --> 01:25:42,140 about smaller and smaller distances. What I think we now know; is that; at some point that's 817 01:25:42,140 --> 01:25:48,620 going to reverse itself and whats going to happen is when you look in more and more detail, things will start 818 01:25:48,800 --> 01:25:55,760 to look fuzzed out over bigger and bigger distances. And so in the end, the most perfect the most accurate 819 01:25:55,760 --> 01:26:02,660 description and the most scrambled description of something is going to be stretched out over the whole 820 01:26:02,780 --> 01:26:11,000 boundary of space. That's called the UVIR connection and what means; UV stands for ultraviolet, it really just 821 01:26:11,120 --> 01:26:16,320 means small distances. IR stands for infrared and it means very big distances 822 01:26:17,260 --> 01:26:22,960 and we are getting a little bit; I don't say "confused" I am not sure its confused. 823 01:26:22,960 --> 01:26:29,460 But something is happening where as you start to look at a system with more and more and more precision 824 01:26:29,600 --> 01:26:36,600 What you might have thought that you gonna see; more and more tiny short distance small distance precision, 825 01:26:36,680 --> 01:26:43,980 its going to start getting fuzzed out and fuzzed out and fuzzed out until its stretched across the whole 826 01:26:43,980 --> 01:26:50,180 And that's not simply a feature of the camera you are using or resolution that is a fundamental feature. 827 01:26:50,180 --> 01:26:56,580 That's a fundamental aspect of Physics, that better you try to look, and the more detail to try to see with 828 01:26:56,580 --> 01:27:01,080 the more its gonna be stretched out and fuzzed out over bigger and bigger distances. 829 01:27:01,080 --> 01:27:06,540 Yeah, I wanna follow up on that; so at least one of the reason why we are now more and more convinced that 830 01:27:06,540 --> 01:27:12,820 holographic principle in really something that works is constantly from string theory; which is my field; 831 01:27:12,820 --> 01:27:18,560 and what happens there is preciously if you go through this step of looking more and more details of what 832 01:27:18,560 --> 01:27:24,560 happens in shorter and shorter distances, you might be interested in; say; what happens inside of our nucleus, 833 01:27:24,560 --> 01:27:30,840 inside of our atoms, and there is nucleus and there are quarks and there are smaller and smaller particles 834 01:27:31,860 --> 01:27:38,860 and suppose again, for a moment; you would wanna forget about gravity, but you start looking more carefully 835 01:27:38,980 --> 01:27:46,900 at what we are made of and then because of this idea that; when you start looking at smaller and smaller scale, 836 01:27:46,900 --> 01:27:52,900 so at least; smaller and smaller distances, suddenly discover that there's actually something new happening 837 01:27:52,900 --> 01:27:58,960 And that something new, at least in terms of your equation; you will recognize it as gravity 838 01:27:58,960 --> 01:28:04,000 So the amazing thing is that what are you actually interested in doing; just looking at the smallest 839 01:28:04,100 --> 01:28:12,180 constituent of matter without pulling gravity in; gravity comes out as something that sort of inevitable. 840 01:28:13,480 --> 01:28:20,280 And to me that's enormously deep lesson there, that; gravity is something that you can not do without. 841 01:28:20,280 --> 01:28:26,060 Clearly we can not do it without it, we would not be sitting here, we would be floating in this, but 842 01:28:26,060 --> 01:28:31,440 Although gravity for me and Stephen Hawking is kind of a pain in the ass sometimes, but; which is why we love 843 01:28:31,560 --> 01:28:37,720 to forget about it but gravity is inevitable but its also a door to this something else. 844 01:28:38,120 --> 01:28:44,300 Its a door to something else but you can get it out of something where you don't put it in. 845 01:28:44,960 --> 01:28:51,960 So its not the starting point, its the output of something. Alright! we're gonna have to ramp this up, lets just 846 01:28:51,960 --> 01:28:55,820 pull the audience; how many of you clap if you think that we are just a projection 847 01:28:58,640 --> 01:29:04,120 Clap if you think if you think we are actually real 848 01:29:06,360 --> 01:29:10,020 and clap if you don't care, 849 01:29:12,400 --> 01:29:17,380 I would have though, that would have gotten the biggest clap of all; this far downtown 850 01:29:18,600 --> 01:29:25,800 First of all; I wanna thank our panel, you have certainly taken us on a great journey tonight 851 01:29:25,800 --> 01:29:31,540 There is obviously so much to think about, I would encourage if you're interested in these ideas; 852 01:29:31,540 --> 01:29:36,240 tomorrow we are actually doing a; rebooting the universe; another exploration of the universe as an 853 01:29:36,500 --> 01:29:42,980 information space; at a panel here. I also encourage you on Sunday; in the Kimmel space upstairs. 854 01:29:43,740 --> 01:29:50,800 Mary Simon and Keystone dancers are going to be doing a fabulous; sort of mapping of dance; on to the 855 01:29:51,100 --> 01:29:59,140 messier catalog and objects in the Universe to this idea of one information space mapping on to another as a 856 01:29:59,140 --> 01:30:02,840 theme here at the world science festival. I encourage to explore all of it. 857 01:30:02,880 --> 01:30:08,560 Thank you so much for coming and thanks to the panel