Transcript
00:00:00 The following is a conversation with Roger Penrose,
00:00:02 physicist, mathematician, and philosopher
00:00:05 at University of Oxford.
00:00:07 He has made fundamental contributions in many disciplines
00:00:10 from the mathematical physics of general relativity
00:00:13 and cosmology to the limitations
00:00:15 of a computational view of consciousness.
00:00:18 In his book, The Emperor’s New Mind,
00:00:20 Roger writes that, quote,
00:00:22 “‘Children are not afraid to pose basic questions
00:00:26 that may embarrass us as adults to ask.’
00:00:29 In many ways, my goal with this podcast
00:00:32 is to embrace the inner child
00:00:33 that is not constrained by how one should behave,
00:00:36 speak, and think in the adult world.
00:00:41 Roger is one of the most important minds of our time,
00:00:44 so it was truly a pleasure and an honor to talk with him.
00:00:49 This conversation was recorded
00:00:50 before the outbreak of the pandemic.
00:00:52 For everyone feeling the medical, psychological,
00:00:55 and financial burden of the crisis,
00:00:57 I’m sending love your way.
00:00:59 Stay strong, we’re in this together, we’ll beat this thing.
00:01:04 This is the Artificial Intelligence Podcast.
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00:01:14 at Lex Friedman, spelled F R I D M A N.
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00:03:46 And now, here’s my conversation with Roger Penrose.
00:03:51 You mentioned in conversation with Eric Weinstein
00:03:54 on the Portal podcast that 2001 Space Odyssey
00:03:57 is your favorite movie.
00:03:59 Which aspect, if you could mention,
00:04:02 of its representation of artificial intelligence,
00:04:05 science, engineering connected with you?
00:04:07 There are all sorts of scenes there which are so amazing.
00:04:11 And how science was so well done.
00:04:14 I mean, people say, oh no, Interstellar is this amazing movie
00:04:19 which is the most scientific movie.
00:04:21 I thought it’s not a patch on 2001.
00:04:24 I mean, 2001, they really went into all sorts of details.
00:04:29 And regarding getting the free fall well done and everything,
00:04:33 I thought it was extremely well done.
00:04:35 So just the details were mesmerizing in terms of this.
00:04:38 And also things like the scene where at the beginning
00:04:43 they have these sort of human ancestors
00:04:45 which are sort of apes becoming humans.
00:04:49 The monolith.
00:04:50 Yes, and well, it’s the one where he throws the bone
00:04:53 up into the air and then it becomes this.
00:04:57 I mean, that’s an amazing sequence there.
00:05:00 What do you make of the monolith?
00:05:01 Does it have any scientific or philosophical meaning to you,
00:05:06 this kind of thing that sparks innovation?
00:05:08 Not really.
00:05:09 That comes from Arthur C. Clarke.
00:05:12 I was always a great fan of Arthur C. Clarke.
00:05:14 So it’s just a nice plot device.
00:05:16 Yeah, that plot is excellent, yes.
00:05:18 So Hal 9000 decides to get rid of the astronauts
00:05:22 because he, it, she believes that they will interfere
00:05:26 with the mission.
00:05:27 That’s right.
00:05:28 Yeah, well, there you are.
00:05:29 It’s this view.
00:05:30 I don’t know whether I disagree with it
00:05:31 because in a certain sense it was telling you it’s wrong.
00:05:35 See, the machine seemed to think it was superior
00:05:39 to the human and so it was entitled to get rid
00:05:45 of the human beings and run the show itself.
00:05:47 Well, do you think Hal did the right thing?
00:05:49 Do you think Hal’s flawed evil?
00:05:52 Or if we think about systems like Hal,
00:05:55 would we want Hal to do the same thing in the future?
00:05:58 What was the flaw there?
00:05:58 Well, you’re basically touching on questions.
00:06:01 You see, it’s one supposed to believe
00:06:04 that Hal was actually conscious.
00:06:06 I mean, it was played rather that way,
00:06:10 as though Hal was a conscious being.
00:06:13 Because Hal showed some pain, some cognizance,
00:06:19 Hal appeared to be cognizant of what it means to die.
00:06:24 Yes.
00:06:25 And therefore had an inkling of consciousness.
00:06:28 Yeah, I mean, I’m not sure that aspect
00:06:30 of it was made completely clear,
00:06:32 whether Hal was really just a very sophisticated computer,
00:06:37 which really didn’t actually have these feelings
00:06:39 and somehow, but you’re right,
00:06:42 it didn’t like the idea of being turned off.
00:06:45 How does it change things if Hal was or wasn’t conscious?
00:06:49 Well, it might say that it would be wrong to turn it off
00:06:53 if it was actually conscious.
00:06:55 I mean, these questions arise if you think.
00:06:57 I mean, AI, one of the ideas,
00:07:00 it’s sort of a mixture in a sense.
00:07:01 You say, if it’s trying to do everything a human can do,
00:07:05 and if you take the view that consciousness
00:07:08 is something which would come along
00:07:10 when the computer is sufficiently complicated,
00:07:13 sufficiently whatever criterion you use
00:07:16 to characterize its consciousness
00:07:20 in terms of some computational criteria,
00:07:24 computational criterion.
00:07:28 So how does consciousness change our evaluation
00:07:33 of the decision that Hal made?
00:07:35 I guess I was trying to say
00:07:36 that people are a bit confused about this,
00:07:38 because if they say these machines will become conscious,
00:07:42 but just simply because it’s a degree of computation,
00:07:45 and when you get beyond that certain degree of computation,
00:07:48 it will become conscious,
00:07:49 then of course you have all these problems.
00:07:52 I mean, you might say, well,
00:07:53 one of the reasons you’re doing AI
00:07:55 is because you want to send a device
00:07:57 out to some distant planet,
00:07:59 and you don’t want to send a human out there,
00:08:01 because then you’d have to bring it back again,
00:08:02 and that costs you far more
00:08:04 than just sending it there and leaving it there.
00:08:07 But if this device is actually a conscious entity,
00:08:10 then you have to face up to the fact that that’s immoral.
00:08:13 And so the mere fact that you’re making some AI device
00:08:17 and thinking that removes your responsibility to it
00:08:24 would be incorrect.
00:08:25 And so this is a sign of flaw in that kind of viewpoint.
00:08:29 I’m not sure how people who take it very seriously,
00:08:35 I mean, I had this curious conversation
00:08:37 with, I’m going to forget names, I’m afraid,
00:08:40 because this is what happens to me at the wrong moment,
00:08:43 Hofstadter, Douglas Hofstadter.
00:08:45 Douglas Hofstadter, yeah.
00:08:46 And he’d written this book,
00:08:48 God Will Let You Up, which I liked.
00:08:50 I thought it was a fantastic book.
00:08:52 But I didn’t agree with his conclusion
00:08:55 from Gödel’s theorem.
00:08:56 I think he got it wrong, you see.
00:08:58 Well, I’ll just tell you my story, you see,
00:09:01 because I’d never met him.
00:09:02 And then I knew I was going to meet him,
00:09:04 the occasion I realized he was coming in,
00:09:06 he wanted to talk to me, and I said, that’s fine.
00:09:09 And I thought in my mind,
00:09:10 well, I’m going to paint him into a corner, you see,
00:09:12 because I’ll use his arguments to convince him
00:09:15 that certain numbers are conscious.
00:09:19 Some integers, large enough integers are actually conscious.
00:09:22 And this was going to be my reductio ad absurdum.
00:09:25 So I started having this argument with him.
00:09:26 He simply leapt into the corner.
00:09:28 He didn’t even need to be painted into it.
00:09:31 He took the view that certain numbers were conscious.
00:09:33 I thought that was a reductio ad absurdum,
00:09:35 but he seemed to think it was perfectly
00:09:37 a reasonable point of view.
00:09:38 Without the absurdum there.
00:09:40 Yes.
00:09:41 Interesting, but the thing you mentioned about how
00:09:44 is the intuition that a lot of the people,
00:09:46 at least in the artificial intelligence world,
00:09:48 had and have, I think.
00:09:51 They don’t make it explicit,
00:09:52 but that if you increase the power of computation,
00:09:56 naturally consciousness will emerge.
00:09:58 Yes, I think that’s what they think.
00:10:00 But basically that’s because
00:10:01 they can’t think of anything else.
00:10:02 Well, that’s right.
00:10:03 And so it’s a reasonable thing.
00:10:05 I mean, you think, what does the brain do?
00:10:06 Well, it does do a lot of computation.
00:10:09 I think most of what you actually call computation
00:10:11 is done by the cerebellum.
00:10:13 I mean, this is one of the things
00:10:15 that people don’t much mention.
00:10:17 I mean, I come to this subject from the outside
00:10:19 and certain things strike me,
00:10:21 which you hardly ever hear mentioned.
00:10:24 I mean, you hear mentioned about the left right business.
00:10:28 They move your right arm,
00:10:30 that’s the left side of the brain
00:10:31 and so on and all that sort of stuff.
00:10:34 And it’s more than that.
00:10:36 If you have these plots of different parts of the brain,
00:10:40 there are two of these things called the homunculi,
00:10:43 which you see these pictures of a distorted human figure
00:10:47 and showing different parts of the brain,
00:10:51 controlling different parts of the body.
00:10:53 And it’s not simply things like,
00:10:55 okay, the right hand is controlled
00:10:58 and both sensory and motor on the left side,
00:11:03 left hand on the right side.
00:11:04 It’s more than that.
00:11:05 Vision is the back basically,
00:11:08 your feet at the top.
00:11:11 And it’s as though it’s about the worst organization
00:11:13 you could imagine.
00:11:14 So it can’t just be a mistake in nature.
00:11:17 There’s something going on there.
00:11:19 And this is made more pronounced
00:11:22 when you think of the cerebellum.
00:11:25 The cerebellum has,
00:11:27 when I was first thinking about these things,
00:11:29 I was told that it had half as many neurons
00:11:32 or something like that, comparable.
00:11:33 And now they tell me it’s got far more neurons
00:11:36 than the cerebrum, and cerebrum is this sort of
00:11:39 convoluted thing at the top people always talk about.
00:11:42 Cerebellum is this thing just looks a bit like
00:11:44 a ball of wool right at the back underneath them.
00:11:47 It’s got more neurons.
00:11:49 It’s got more connections.
00:11:51 Computationally, it’s got much more going on
00:11:55 than this from the cerebrum.
00:11:58 But as far as we know, that’s slightly controversial,
00:12:01 the cerebellum is entirely unconscious.
00:12:04 So the actions, you have a pianist
00:12:07 who plays an incredible piece of music
00:12:09 and think of, and he moves his little finger
00:12:11 into this little key to get it, hit it,
00:12:14 just the right moment.
00:12:15 Does he or she consciously will that movement?
00:12:20 No.
00:12:23 Okay, the consciousness is coming in.
00:12:24 It’s probably to do with the feeling
00:12:26 of the piece of music that’s being performed
00:12:28 and that sort of thing, which is going on.
00:12:31 But the details of what’s going on are controlled.
00:12:35 I would think almost entirely by the cerebellum.
00:12:38 That’s where you have this precision
00:12:40 and the really detailed.
00:12:44 Once you get, I mean, you think of a tennis player
00:12:47 or something, does that tennis player
00:12:48 think exactly which muscles should be moved
00:12:51 in what direction and so on?
00:12:52 No, of course not.
00:12:54 But he or she will maybe think,
00:12:56 well, if the ball is angled in such a way in that corner,
00:12:59 that will be tricky for the opponent.
00:13:02 And the details of that are all done
00:13:06 largely with the cerebellum.
00:13:08 That’s where all the precise motions,
00:13:11 but it’s unconscious.
00:13:13 So why is it interesting to you
00:13:14 that so much computation is done in the cerebellum
00:13:17 and yet it is unconscious?
00:13:19 Because it doesn’t, it’s the view
00:13:21 that somehow it’s computation
00:13:24 which is producing the consciousness.
00:13:27 And it’s here you have an incredible amount
00:13:30 of computation going on.
00:13:33 And as far as we know, it’s completely unconscious.
00:13:36 So why, what’s the difference?
00:13:39 And I think it’s an important thing.
00:13:41 What’s the difference?
00:13:43 Why is the cerebrum, all this very peculiar stuff
00:13:47 that very hard to see on a computational perspective,
00:13:51 like having the, everything have to cross over
00:13:53 under the other side and do something
00:13:55 which looks completely inefficient.
00:13:58 And you’ve got funny things like the frontal lobe
00:14:01 and the, what do we call the lobes?
00:14:04 And the place where they come together,
00:14:07 you have the different parts, the control,
00:14:12 you see one to do with motor
00:14:13 and the other to do with sensory.
00:14:16 And they’re sort of opposite each other
00:14:17 rather than being connected by,
00:14:20 it’s not as though you’ve got electrical circuits.
00:14:23 There’s something else going on there.
00:14:26 So it’s just the idea that it’s like a complicated computer
00:14:30 just seems to me to be completely missing the point.
00:14:34 There must be a lot of computation going on,
00:14:37 but the cerebellum seems to be much better at doing that
00:14:40 than the cerebrum is.
00:14:42 So for sure, I think what explains it is like half hope
00:14:47 and half we don’t know what’s going on.
00:14:49 And therefore from the computer science perspective,
00:14:52 you hope that a Turing machine can be perfectly,
00:14:56 can achieve general intelligence.
00:14:58 Well, you have this wonderful thing about Turing
00:15:02 and Gödel and Church and Curry and various people,
00:15:07 particularly Turing, and I guess Post was the other one.
00:15:11 These people who developed the idea
00:15:14 of what a computation is.
00:15:17 And there were different ideas of what a computation,
00:15:19 developed differently.
00:15:20 I mean, Church’s way of doing it,
00:15:21 was very different from Turing’s,
00:15:24 but then they were shown to be equivalent.
00:15:26 And so the view emerged that what we mean by computation
00:15:32 is a very clear concept.
00:15:34 And one of the wonderful things that Turing did
00:15:37 was to show that you could have
00:15:40 what we call the universal Turing machine.
00:15:43 It’s you just have to have a certain finite device.
00:15:46 Okay, it has to have an unlimited storage space,
00:15:48 which is accessible to it,
00:15:50 but the actual computation, if you like,
00:15:51 is performed by this one universal device.
00:15:55 And so the view comes away,
00:15:57 well, you have this universal Turing machine,
00:16:01 and maybe the brain is something like that,
00:16:03 a universal Turing machine,
00:16:05 and it’s got maybe not unlimited storage,
00:16:08 but a huge storage accessible to it.
00:16:12 And this model is one,
00:16:14 which is what’s used in ordinary computation.
00:16:17 It’s a very powerful model.
00:16:19 And the universallness of computation is very useful.
00:16:24 You could have some problem
00:16:26 and you may not see immediately
00:16:27 how to put it onto a computer,
00:16:29 but if it is something of that nature,
00:16:32 then there are all sorts of subprograms
00:16:36 and subroutines when all the,
00:16:37 I mean, I learned a little bit of computing
00:16:38 when I was a student, but not very much.
00:16:42 But it was enough to get the general ideas.
00:16:45 And there’s something really pleasant
00:16:46 about a formal system like that.
00:16:48 Yeah.
00:16:49 Where you can start discussing about what’s provable,
00:16:51 what’s not, these kinds of things.
00:16:52 And you’ve got a notion, which is an absolute notion,
00:16:55 this notion of computability,
00:16:56 and you can address when things are,
00:17:00 mathematical problems are computably solvable
00:17:02 and what chance.
00:17:03 So.
00:17:04 And it’s a very beautiful area of mathematics,
00:17:06 and it’s a very powerful area of mathematics.
00:17:09 And it underlies the whole sort of,
00:17:14 I won’t say, the principles of computing machines
00:17:18 that we have today.
00:17:19 Could you say, what is Gayle’s Incompleteness Theorem?
00:17:22 And how does it, maybe also say,
00:17:24 is it heartbreaking to you?
00:17:26 And how does it interfere with this notion of computation
00:17:31 and consciousness?
00:17:32 Sure.
00:17:33 Well, the ideas, basically ideas,
00:17:36 which I formulated in my first year
00:17:39 as a graduate student in Cambridge.
00:17:41 I did my undergraduate work in mathematics in London,
00:17:44 and I had a colleague, Ian Percival.
00:17:47 We used to discuss things like computational
00:17:49 and logical systems quite a lot.
00:17:52 I’d heard about Gayle’s theorem.
00:17:53 I was a bit worried by the idea that it seemed to say
00:17:55 there were things in mathematics that you could never prove.
00:17:59 And so when I went to Cambridge as a graduate student,
00:18:04 I went to various courses.
00:18:06 You see, I was doing pure mathematics.
00:18:08 I was doing algebraic geometry of a sort.
00:18:11 A little bit different from what my supervisor and people,
00:18:15 but it was algebraic geometry.
00:18:16 Yeah.
00:18:17 And I was interested,
00:18:20 I got particularly interested in three lecture courses
00:18:24 that were nothing to do with what I was supposed
00:18:27 to be doing.
00:18:28 One was a course by Herman Bondy
00:18:30 on Einstein’s general theory of relativity,
00:18:33 which was a beautiful course.
00:18:34 He was an amazing lecturer,
00:18:37 brought these things alive, absolutely.
00:18:40 Another was a course on quantum mechanics
00:18:43 given by a great physicist, Paul Dirac.
00:18:47 Very beautiful course in a completely different way.
00:18:50 It was, he was very kind of organized
00:18:52 and never got excited about anything seemingly.
00:18:58 But it was extremely well put together.
00:19:00 And I found that amazing too.
00:19:03 Third course that was nothing to do
00:19:04 with what I should be doing was a course
00:19:06 on mathematical logic.
00:19:08 I got excited, as I say, my discussions with Ian Percival
00:19:12 was incompleteness theorem already deeply
00:19:15 within mathematical logic space.
00:19:18 Were you introduced to it?
00:19:20 I was introduced to it in detail by the course, by Steen.
00:19:25 And he, it was two things he described
00:19:27 which were very fundamental to my understanding.
00:19:31 One was Turing machines and the whole idea
00:19:34 of computability and all that.
00:19:35 So that was all very much part of the course.
00:19:38 The other one was the Gödel theorem.
00:19:41 And it wasn’t what I was afraid it was
00:19:43 to tell you there were things in mathematics
00:19:45 you couldn’t prove.
00:19:47 It was basically, and he phrased it in a way
00:19:51 which often people didn’t.
00:19:53 And if you read Douglas Soft status book,
00:19:54 he doesn’t, you see.
00:19:56 But Steen made it very clear.
00:19:58 And also in a sort of public lecture
00:20:01 that he gave to a mathematical,
00:20:02 I think it may be the Adams Society,
00:20:04 one of the mathematical undergraduate societies.
00:20:07 And he made this point again very clearly.
00:20:09 That if you’ve got a formal system of proof,
00:20:11 so suppose what you mean by proof
00:20:15 is something which you could check with a computer.
00:20:19 So to say whether you’ve got it right or not,
00:20:21 you’ve got a lot of steps.
00:20:22 Have you carried this computational procedure?
00:20:25 Well, following the proof, steps of the proof correctly,
00:20:30 that can be checked by an algorithm, by a computer.
00:20:35 So that’s the key thing.
00:20:38 Now what you have to, now you see, is this any good?
00:20:44 If you’ve got an algorithmic system,
00:20:47 which claims to say, yes, this is right,
00:20:49 this you’ve proved it correctly, this is true.
00:20:52 If you’ve proved it, if you made a mistake,
00:20:54 it doesn’t say it’s true or false.
00:20:55 But if you have, if you’ve done it right,
00:20:57 then the conclusion you’ve come to is correct.
00:21:01 Now you say, why do you believe it’s correct?
00:21:03 Because you’ve looked at the rules and you said,
00:21:05 well, okay, that one’s all right.
00:21:06 Yeah, that one’s all right.
00:21:07 What about that?
00:21:08 Oh, yeah, I see, I see why it’s all right.
00:21:10 Okay, you go through all the rules.
00:21:12 You say, yes, following those rules,
00:21:13 if it says, yes, it’s true, it is true.
00:21:17 So you’ve got to make sure that these rules
00:21:19 are ones that you trust.
00:21:21 If you follow the rules and it says it’s a proof,
00:21:25 is the result actually true?
00:21:27 Right.
00:21:27 And that your belief that it’s true
00:21:29 depends upon looking at the rules and understanding them.
00:21:33 Now, what Gödel shows, that if you have such a system,
00:21:38 then you can construct a statement of the very kind
00:21:41 that it’s supposed to look at, a mathematical statement,
00:21:44 and you can see by the way it’s constructed
00:21:47 and what it means that it’s true,
00:21:52 but not provable by the rules that you’ve been given.
00:21:56 And it depends on your trust in the rules.
00:21:59 Do you believe that the rules only give you truths?
00:22:02 If you believe the rules only give you truths,
00:22:04 then you believe this other statement is also true.
00:22:07 I found this absolutely mind blowing.
00:22:09 When I saw this, it blew my mind.
00:22:12 I thought, my God, you can see that this statement is true.
00:22:17 It’s as good as any proof,
00:22:18 because it only depends on your belief
00:22:21 in the reliability of the proof procedure, that’s all it is,
00:22:25 and understanding that the coding is done correctly.
00:22:29 And it enables you to transcend that system.
00:22:33 So whatever system you have,
00:22:36 as long as you can understand what it’s doing
00:22:39 and why you believe it only gives you truths,
00:22:41 then you can see beyond that system.
00:22:44 Now, how do you see beyond it?
00:22:46 What is it that enables you to transcend that system?
00:22:51 Well, it’s your understanding
00:22:53 of what the system is actually saying
00:22:55 and what the statement that you’ve constructed
00:22:57 is actually saying.
00:22:59 So it’s this quality of understanding, whatever it is,
00:23:03 which is not governed by rules.
00:23:05 It’s not a computational procedure.
00:23:07 So this idea of understanding is not going to be
00:23:09 within the rules of the, within the formal system.
00:23:13 Yes, you’re only using those rules anyway,
00:23:15 because you have understood them to be rules
00:23:18 which only give you truths.
00:23:20 There’d be no point in it otherwise.
00:23:22 I mean, people say, well, okay, this is,
00:23:24 it’s one set of rules as good as any other.
00:23:28 Well, it’s not true.
00:23:28 You see, you have to understand what the rules mean.
00:23:31 And why does that understanding of the mean
00:23:33 give you something beyond the rules themselves?
00:23:36 And that’s what it was.
00:23:37 That’s what blew my mind.
00:23:38 It’s somehow understanding why the rules give you truths
00:23:43 enables you to transcend the rules.
00:23:45 So that’s where, I mean, even at that time,
00:23:48 that’s already where the thought entered your mind
00:23:50 that the idea of understanding, or we can start calling it
00:23:55 things like intelligence or even consciousness
00:23:57 is outside the rules.
00:23:59 Yes.
00:24:00 See, I’ve always concentrated on understanding.
00:24:02 You know, people say, people come and point out things.
00:24:05 Well, you know, what about creativity?
00:24:07 That’s something a machine can’t do is create.
00:24:09 Well, I don’t know.
00:24:09 What is creativity?
00:24:11 And I don’t know.
00:24:12 You know, somebody can put some funny things
00:24:13 on a piece of paper and say that’s creative
00:24:15 and you could make a machine do that.
00:24:16 Is it really creative?
00:24:18 I don’t know.
00:24:18 You see, I worry about that one.
00:24:20 I sort of agree with it in a sense,
00:24:22 but it’s so hard to do anything with that statement.
00:24:25 But understanding, yes, you can.
00:24:27 You can make, go see that understanding, whatever it is,
00:24:32 and it’s very hard to put your finger on it.
00:24:34 That’s absolutely true.
00:24:35 Can you try to define or maybe dance around
00:24:39 a definition of understanding?
00:24:41 To some degree, but I don’t, I often wondered about this,
00:24:45 but there is something there which is very slippery.
00:24:48 It’s something like standing back.
00:24:52 And it’s got to be something, you see,
00:24:54 it’s also got to be something which was of value
00:24:56 to our remote ancestors.
00:24:58 Right.
00:24:59 Because sometimes, there’s a cartoon
00:25:01 which I drew sometimes showing you how all these,
00:25:04 there’s in the foreground, you see this mathematician
00:25:07 just doing some mathematical theorem.
00:25:08 There’s a little bit of a joke in that theorem,
00:25:10 but let’s not go into that.
00:25:12 He’s trying to prove some theorem.
00:25:14 And he’s about to be eaten by a saber tooth tiger
00:25:17 who’s hiding in the undergrowth, you see.
00:25:21 And in the distance, you see his cousins
00:25:24 building, growing crops, building shelters,
00:25:29 domesticating animals, and in the slight foreground,
00:25:31 you see they’ve built a mammoth trap
00:25:33 and this poor old mammoth is falling into a pit, you see,
00:25:36 and all these people around them are about to grab him,
00:25:39 you see, and well, you see, those are the ones who,
00:25:43 the quality of understanding, which goes with all,
00:25:47 it’s not just the mathematician doing his mathematics,
00:25:50 this understanding quality is something else,
00:25:53 which has been a tremendous advantage to us,
00:25:58 not just to us.
00:25:59 See, I don’t think consciousness is limited to humans.
00:26:03 Yeah, that’s the interesting question,
00:26:04 at which point, if it is indeed connected
00:26:07 to the evolutionary process,
00:26:09 at which point did we pick up this?
00:26:11 A very hard question.
00:26:13 It’s certainly, I don’t think it’s primates,
00:26:15 you know, you see these pictures of African hunting dogs
00:26:20 and how they can plan amongst themselves
00:26:22 how to catch the antelopes.
00:26:25 Some of these David Attenborough films,
00:26:27 I think this probably was one of them,
00:26:29 and you could see the hunting dogs,
00:26:31 and they divide themselves into two groups
00:26:34 and they go in two routes, two different routes.
00:26:36 One of them goes and they sort of hide next to the river.
00:26:40 And the other group goes around
00:26:42 and they start yelping at these, they don’t bark,
00:26:46 I guess whatever noise hunting dogs do,
00:26:48 the antelopes, and they sort of round them up
00:26:51 and they chase them in the direction of the river.
00:26:54 And there are the other ones just waiting for them,
00:26:56 just to get, because when they get to the river,
00:26:58 it slows them down.
00:27:00 And so they pounce on them.
00:27:02 So they’ve obviously planned this all out somehow.
00:27:05 I have no idea how.
00:27:07 And there is some element of conscious planning,
00:27:11 as far as I can see.
00:27:12 I don’t think it’s just some kind of,
00:27:16 so much of AI these days is done on what they call
00:27:19 bottom up systems, is it?
00:27:21 Yeah, where you have neural networks
00:27:23 and you give them a zillion different things to look at
00:27:27 and then they sort of can choose one thing over another,
00:27:33 just because it’s seen so many examples
00:27:35 and picks up on little signals,
00:27:38 which one may not even be conscious of.
00:27:41 And that doesn’t feel like understanding.
00:27:43 There’s no understanding in that whatsoever.
00:27:46 Well, you’re being a little bit human centric, so.
00:27:49 Well, I’m talking about, I’m not with the dogs, am I?
00:27:52 No, you’re not.
00:27:53 Sorry, not human centric, but I misspoke.
00:27:56 Biology centric.
00:27:59 Is it possible that consciousness
00:28:00 would just look slightly different?
00:28:03 Well, I’m not saying it’s biological,
00:28:04 because we don’t know.
00:28:06 I think other examples of elephants
00:28:08 is a wonderful example, too.
00:28:10 Where they, this was, I think this was an Attenborough one,
00:28:13 where the elephants have to go from along,
00:28:17 the troop of them have to go long distances.
00:28:20 And the leader of a troop is a female.
00:28:21 They all are, apparently.
00:28:23 And this female, she had to go all the way
00:28:26 from one part of the country to another.
00:28:30 And at a certain point, she made a detour.
00:28:32 And they went off in this big detour.
00:28:35 All the troop came with her.
00:28:37 And this was where her sister had died.
00:28:39 And there were her bones lying around.
00:28:41 And they’re going to pick up the bones,
00:28:42 and they hand it around, and they caress the bones.
00:28:45 And then they put them back, and they go back again.
00:28:48 What in the hell are they doing?
00:28:51 That’s so interesting.
00:28:52 I mean, there’s something going on.
00:28:54 There’s no clear connection with natural selection.
00:28:59 There’s just some deep feeling going on there,
00:29:03 which has to do with their conscious experience.
00:29:06 And I think it’s something that, overall,
00:29:09 is advantageous, our natural selection,
00:29:15 but not directly to do with natural selection.
00:29:18 I like that.
00:29:19 There’s something going on there.
00:29:22 Like I told you, I’m Russian,
00:29:24 so I tend to romanticize all things of this nature,
00:29:28 that it’s not merely cold, hard computation.
00:29:33 Perhaps I could just slightly answer your question.
00:29:35 You were asking me, what is it?
00:29:38 There’s something about sort of standing back
00:29:41 and thinking about your own thought processes.
00:29:44 I mean, there is something like that in the Gödel thing,
00:29:47 because you’re not following the rules.
00:29:50 You’re standing back and thinking about the rules.
00:29:53 And so there is something that you might say,
00:29:56 you think about you’re doing something,
00:29:58 and you think, what the hell am I doing?
00:30:00 And you sort of stand back and think about
00:30:02 what it is that’s making you think in such a way.
00:30:05 Just take a step back outside the game you’ve been playing.
00:30:08 Yeah, you back up and you think about,
00:30:10 you’re just not playing the game anymore.
00:30:12 You’re thinking about what the hell you’re doing
00:30:14 in playing this game.
00:30:16 And that’s somehow,
00:30:18 it’s not a very precise description,
00:30:20 but somehow it feels very true
00:30:22 that that’s somehow understanding.
00:30:24 This kind of reflection.
00:30:26 The reflection, yes.
00:30:27 Yeah, it’s a bit hard to put your finger on,
00:30:30 but there is something there,
00:30:31 which I think maybe could be unearthed at some point
00:30:34 and see this is really what’s going on,
00:30:36 why conscious beings have this advantage,
00:30:40 what it is that gives them advantage.
00:30:42 And I think it goes way back.
00:30:44 I don’t think we’re talking about the hunting dogs
00:30:46 and the elephants.
00:30:48 It’s pretty clear that octopuses have
00:30:51 the same sort of quality,
00:30:53 and we call it consciousness.
00:30:54 Yeah, I think so.
00:30:55 Seen enough examples of the way that they behave
00:30:58 and the evolution route is completely different.
00:31:03 Does it go way back to some common ancestor
00:31:05 or did it come separately?
00:31:07 My hope is it’s something simple,
00:31:09 but the hard question if there’s a hardware prerequisite.
00:31:13 We have to develop some kind of hardware mechanisms
00:31:17 in our computers.
00:31:19 Like basically, as you suggest,
00:31:21 we’ll get to in a second,
00:31:22 we kind of have to throw away the computer
00:31:24 as we know it today.
00:31:26 Yeah.
00:31:26 The deterministic machines we know today
00:31:28 to try to create it.
00:31:29 I mean, my hope, of course, is not, but…
00:31:35 Well, I should go really back to the story
00:31:37 which, in a sense, I haven’t finished
00:31:39 because I went to these three courses, you see,
00:31:41 when I was a graduate student.
00:31:43 And so I started to think, well, I’m really,
00:31:46 I’m a pretty, what you might call a materialist
00:31:49 in the sense of thinking that there’s no kind of mystical
00:31:53 something or other which comes in from who knows where.
00:31:55 You still that?
00:31:56 Are you still, throughout your life, been a materialist?
00:31:58 I don’t like the word materialist
00:32:00 because it suggests we know what material is.
00:32:02 And that is a bad word because…
00:32:06 But there’s no mystical.
00:32:07 It’s not some mystical something
00:32:09 which is not treatable by science.
00:32:11 That’s so beautifully put,
00:32:12 just to pause on that for a second.
00:32:14 You’re a materialist, but you acknowledge
00:32:17 that we don’t really know what the material is.
00:32:19 That’s right.
00:32:19 I mean, I like to call myself a scientist, I suppose,
00:32:24 but it means that…
00:32:27 Yes, well, you see, the question goes on here.
00:32:30 So I began thinking, okay, if consciousness
00:32:33 or understanding is something
00:32:35 which is not a computational process, what can it be?
00:32:40 And I knew enough from my undergraduate work.
00:32:42 I knew about Newtonian mechanics,
00:32:44 and I knew how basically you could put it on a computer.
00:32:50 There is a fundamental issue, which is it important or not?
00:32:54 That computation depends upon discrete things.
00:32:59 So you’re using discrete elements,
00:33:02 whereas the physical laws depend on the continuum.
00:33:06 Now, is this something to do with it?
00:33:09 Is it the fact that we use the continuum in our physics?
00:33:12 And if we model our physical system,
00:33:15 we use discrete systems like ordinary computers?
00:33:19 I came to the view that that’s probably not it.
00:33:22 I might have to retract on that someday,
00:33:24 but the view was no, you can get close enough.
00:33:28 It’s not altogether clear, I have to say,
00:33:30 but you can get close enough.
00:33:32 And I went to this course by Bondi on general relativity,
00:33:37 and I thought, well, you can put that on a computer,
00:33:39 because that was a long time before people,
00:33:42 and I’ve sort of grown up with this,
00:33:43 how people have done better and better calculations,
00:33:46 and they could work out about black holes,
00:33:48 and they can then work out how black holes
00:33:50 can interact with each other, spiral around,
00:33:52 and what kind of gravitational waves can out.
00:33:55 And it’s a very impressive piece of computational work,
00:33:58 how you can actually work out the shapes of those signals.
00:34:01 And now we have LIGO seeing these signals,
00:34:04 and they say, yeah, those black holes spiral into each other.
00:34:07 This is just a vindication of the power of computation
00:34:11 in describing Einstein’s general relativity.
00:34:16 So in that case, we can get close,
00:34:18 but with computation, we can get close
00:34:22 to our understanding of the physics.
00:34:23 You can get very, very close.
00:34:24 Now, is that close enough, you see?
00:34:26 And then I went to this course by Dirac.
00:34:29 Now, you see, I think it was the very first lecture
00:34:32 that he gave, and he was talking about
00:34:35 a superposition principle.
00:34:37 And he said, if you have a particle,
00:34:39 you usually think of particle can be over here
00:34:41 or over there, but in quantum mechanics,
00:34:44 it can be over here and over there at the same time.
00:34:48 And you have these states which involve
00:34:50 a superposition in some sense
00:34:52 of different locations for that particle.
00:34:56 And then he got out his piece of chalk.
00:34:58 Some people say he broke it in two
00:35:00 as a kind of illustration of how the piece of chalk
00:35:03 might be over here and over there at the same time.
00:35:06 And he was talking about this, and my mind wandered.
00:35:10 I don’t remember what he said.
00:35:13 All I can remember, he’s just moved on to the next topic,
00:35:16 and something about energy he’d mentioned,
00:35:18 which I had no idea what it had to do with anything.
00:35:21 And so I’d been struck with this
00:35:22 and worried about it ever since.
00:35:25 It’s probably just as well I didn’t hear his explanation
00:35:27 because it was probably one of these things
00:35:29 to calm me down and not worry about it anymore.
00:35:32 Whereas in my case, I’ve worried about it ever since.
00:35:35 So I thought maybe that’s the catch.
00:35:38 There is something in quantum mechanics
00:35:41 where the superpositions become one or the other,
00:35:45 and that’s not part of quantum mechanics.
00:35:47 There’s something missing in the theory.
00:35:50 The theory is incomplete.
00:35:51 It’s not just incomplete.
00:35:52 It’s in a certain sense not quite right
00:35:54 because if you follow the equation,
00:35:57 the basic equation of quantum mechanics,
00:35:59 that’s the Schrodinger equation,
00:36:01 you could put that on a computer too.
00:36:02 There are lots of difficulties
00:36:03 about how many parameters you have to put in and so on.
00:36:06 That can be very tricky,
00:36:07 but nevertheless, it is a computational process.
00:36:10 Modulo this question about the continuum as before,
00:36:14 but it’s not clear that makes any difference.
00:36:16 So our theories of quantum mechanics
00:36:18 may be missing the same element
00:36:20 that the universal Turing machine
00:36:23 is missing about consciousness.
00:36:25 Yes, yes.
00:36:26 Yeah, this is the view I held is that you need a theory
00:36:29 and that what people call the reduction of the state
00:36:33 or the collapse of the wave function,
00:36:35 which you have to have,
00:36:36 otherwise quantum mechanics doesn’t relate
00:36:38 to the world we see.
00:36:39 To make it relate to the world we see,
00:36:41 you’ve got to break the Schrodinger equation.
00:36:45 Schrodinger himself was absolutely appalled by this idea,
00:36:49 his own equation.
00:36:50 I mean, that’s why he introduced
00:36:52 this famous Schrodinger’s cat as a thought experiment.
00:36:56 He’s really saying, look,
00:36:57 this is where my equation leads you into it.
00:36:59 There’s something wrong,
00:37:01 something we haven’t understood,
00:37:02 which is basically fundamental.
00:37:05 And so I was trying to put all these things together
00:37:07 and said, well, it’s got to be
00:37:09 the noncomputability comes in there.
00:37:11 And I also can’t quite remember when I thought this,
00:37:14 but it’s when gravity is involved in quantum mechanics.
00:37:18 It’s the combination of those two.
00:37:19 And that’s that point
00:37:22 when you have good reasons to believe,
00:37:25 this came much later,
00:37:27 that I have good reason to believe
00:37:29 that the principles of general relativity
00:37:32 and those of quantum mechanics,
00:37:34 most particularly,
00:37:35 it’s the basic principle of equivalence,
00:37:39 which goes back to Galileo.
00:37:41 If you fall freely,
00:37:43 you eliminate the gravitational field.
00:37:46 So you imagine Galileo
00:37:49 dropping his big rock and his little rock
00:37:51 from the leaning tower,
00:37:52 whether he actually ever did that or not,
00:37:54 pretty irrelevant.
00:37:55 And as the rocks fall to the ground,
00:37:57 you have a little insect sitting on one of them,
00:37:59 looking at the other one.
00:38:01 And it seems to think, oh, there’s no gravity here.
00:38:04 Of course, it hits the ground
00:38:05 and then you realize something’s difference going on.
00:38:07 But when it’s in free fall,
00:38:10 the gravity has been eliminated.
00:38:11 Galileo understood that very beautifully.
00:38:15 He gives these wonderful examples of fireworks.
00:38:18 And you see the fireworks and explode,
00:38:20 and you see this fear of sparkling fireworks.
00:38:23 It remains as fear as it falls down,
00:38:26 as though there were no gravity.
00:38:29 So he understood that principle,
00:38:31 but he couldn’t make a theory out of it.
00:38:33 Einstein came along,
00:38:34 used exactly the same principle.
00:38:36 And that’s the basis
00:38:38 of Einstein’s general theory of relativity.
00:38:41 Now, there is a conflict.
00:38:43 This is something I did much, much later.
00:38:45 So this wasn’t at those days,
00:38:47 much, much later.
00:38:48 You can see there is a basic conflict
00:38:51 between the principle of superposition,
00:38:54 the thing that Dirac was talking about,
00:38:56 and the principle of general covariance.
00:38:58 Well, principle of equivalence.
00:39:01 Gravitational field’s equivalent to an acceleration.
00:39:03 Can you pause for a second?
00:39:04 What is the principle of equivalence?
00:39:06 It’s this Galileo principle
00:39:08 that we can eliminate, at least locally.
00:39:11 You have to be in a small neighborhood
00:39:13 because if you have people dropping rocks
00:39:16 all around the world somewhere,
00:39:18 you can’t get rid of it all at once.
00:39:19 But in the local neighborhood,
00:39:22 you can eliminate the gravitational field
00:39:24 by falling freely with it.
00:39:26 And we now see this with astronauts,
00:39:28 and they don’t, you know, the Earth is right there.
00:39:30 You can see the great globe of the Earth
00:39:32 right beneath them.
00:39:33 But they don’t care about it.
00:39:35 As far as they’re concerned, there’s no gravity.
00:39:39 They fall freely within the gravitational field,
00:39:42 and that gets rid of the gravitational field.
00:39:45 And that’s the principle of equivalence.
00:39:46 So what’s the contradiction?
00:39:48 What’s the tension with superposition
00:39:50 and equivalence?
00:39:51 Oh, well, that’s technical.
00:39:52 So just to backtrack for a second
00:39:55 just to see if we can weave a thread through it all.
00:39:57 So we started to think about consciousness
00:40:02 as potentially needing some of the same,
00:40:06 not mystical, but some of the same magic.
00:40:08 You see, it is a complicated story.
00:40:10 So, you know, people think,
00:40:11 oh, I’m drifting away from the point or something.
00:40:14 But I think it is a complicated story.
00:40:16 So what I’m trying to say,
00:40:17 I mean, I try to put it in a nutshell,
00:40:19 but it’s not so easy.
00:40:20 I’m trying to say that whatever consciousness is,
00:40:24 it’s not a computation.
00:40:27 Or it’s not a physical process
00:40:29 which can be described by computation.
00:40:33 But it nevertheless could be,
00:40:34 so one of the interesting models
00:40:37 that you’ve proposed
00:40:39 is the orchestrated objective reduction.
00:40:41 Yes, well, you see, that’s going from there, you see.
00:40:44 So I say I have no idea.
00:40:46 So I wrote this book through my scientific career.
00:40:50 I thought, you know, when I’m retired,
00:40:52 I’ll have enough time to write a sort of a popularish book
00:40:56 which I will explain my ideas and puzzles,
00:41:01 what I like, beautiful things about physics and mathematics,
00:41:04 and this puzzle about computability
00:41:07 and consciousness and so on.
00:41:09 And in the process of writing this book,
00:41:13 well, I thought I’d do it when I was retired.
00:41:14 I didn’t actually, I didn’t wait that long
00:41:16 because there was a radio discussion
00:41:19 between Edward Fredkin and Marvin Minsky.
00:41:24 And they were talking about what computers could do.
00:41:28 And they were entering a big room.
00:41:30 They imagined entering this big room
00:41:32 where at the other end of the room,
00:41:33 two computers were talking to each other.
00:41:36 And as you walk up to the computers,
00:41:39 they will have communicated to each other
00:41:41 more ideas, concepts, things than the entire human race
00:41:46 had ever done.
00:41:49 So I thought, well, I know where you’re coming from,
00:41:51 but I just don’t believe you.
00:41:53 There’s something missing.
00:41:57 So I thought, well, I should write my book.
00:42:00 And so I did.
00:42:01 It was roughly the same time Stephen Hawking
00:42:04 was writing his brief history of time.
00:42:07 In the 80s at some point.
00:42:11 The book you’re talking about is The Emperor’s New Mind.
00:42:12 The Emperor’s New Mind, that’s right.
00:42:13 And both are incredible books,
00:42:16 The Brief History of Time and The Emperor’s New Mind.
00:42:18 Yes, it was quite interesting
00:42:19 because he told me he’d got Carl Sagan, I think,
00:42:23 to write a foreword for the book, you see.
00:42:26 So I thought, gosh, what am I gonna do?
00:42:28 I’m not gonna get anywhere unless I get somebody.
00:42:31 So I said, oh, I know Martin Gardner,
00:42:32 so I wonder if he’d do it.
00:42:34 So he did, and he did a very nice foreword.
00:42:36 So that’s an incredible book,
00:42:38 and some of the same people you mentioned,
00:42:40 Ed Franken, which I guess of expert systems fame,
00:42:44 and Minsky, of course, people know in the AI world,
00:42:46 but they represent the artificial intelligence world
00:42:49 that do hope and dream that AI’s intelligence is.
00:42:53 Well, you see, it was my thinking,
00:42:54 well, you know, I see where they’re coming from.
00:42:57 From that perspective, yeah, you’re right.
00:42:59 But that’s not my perspective.
00:43:01 So I thought I had to say it.
00:43:03 And as I was writing my book, you see,
00:43:05 I thought, well, I don’t really know anything
00:43:06 about neurophysiology.
00:43:07 What am I doing writing this book?
00:43:09 So I started reading up about neurophysiology,
00:43:12 and I read up, and I think,
00:43:13 now, I’m trying to find out how it is
00:43:14 that nerve signals could possibly
00:43:16 preserve quantum coherence.
00:43:18 And all I read is that the electrical signals
00:43:20 which go along the nerves create effects through the brain.
00:43:25 There’s no chance you can isolate it.
00:43:28 So I thought, this is hopeless.
00:43:29 So I come to the end of the book,
00:43:31 and I more or less give up.
00:43:33 I just think of something which I didn’t believe in.
00:43:36 Maybe this is a way around it, but no.
00:43:39 And then, you see, I thought, well,
00:43:40 maybe this book will at least stimulate young people
00:43:43 to do science or something.
00:43:45 And I got all these letters from old, retired people instead.
00:43:48 These are the only people who had time to read my book.
00:43:52 So, I mean, but.
00:43:53 Except for Stuart Hameroff.
00:43:54 Except for Stuart Hameroff.
00:43:56 Stuart Hameroff wrote to me, and he said,
00:43:58 I think you’re missing something.
00:44:01 You don’t know about microtubules, do you?
00:44:03 He didn’t put it quite like that.
00:44:04 But that was more or less it.
00:44:05 And he said, this is what you really need to consider.
00:44:08 So I thought, my God, yes.
00:44:10 That’s a much more promising structure.
00:44:12 So, I mean, fundamentally, you were searching
00:44:16 for the source of, noncomputable source of consciousness
00:44:22 within the human brain, in the biology.
00:44:25 And so, what are, if I may ask, what are microtubules?
00:44:30 Well, you see, I was ignorant in what I’d read.
00:44:33 I never came across them in the books I looked at.
00:44:37 Perhaps I only read rather superficially, which is true.
00:44:40 But I didn’t know about microtubules.
00:44:43 Stuart, I think one of the things
00:44:45 that impressed him about them was,
00:44:47 when you see pictures of mitosis, that’s a cell dividing,
00:44:51 and you see all the chromosomes.
00:44:53 And the chromosomes, they all get lined up,
00:44:55 and then they get pulled apart.
00:44:57 And so, as the cell divides, half the chromosomes go,
00:45:02 they divide into the two parts,
00:45:04 and they go two different ways.
00:45:07 And what is it that’s pulling them apart?
00:45:09 Well, those are these little things called microtubules.
00:45:12 And so, he started to get interested in them.
00:45:15 And he formed the view, well, he was,
00:45:18 his day job or night job or whatever you call it,
00:45:21 is to put people to sleep,
00:45:23 except he doesn’t like calling it sleep
00:45:24 because it’s different.
00:45:25 General anesthetics in a reversible way.
00:45:29 So, you want to make sure that they don’t experience
00:45:32 the pain that would otherwise be something that they feel.
00:45:36 And consciousness is turned off for a while,
00:45:40 and it can be turned back on again.
00:45:41 So, it’s crucial that you can turn it off and turn it on.
00:45:44 And what do you do when you’re doing that?
00:45:47 What do general anesthetic gases do?
00:45:50 And see, he formed the view that it’s the microtubules
00:45:54 that they affect.
00:45:56 And the details of why he formed that view is not,
00:46:01 well, they’re clear to me,
00:46:02 but there’s an interesting story he keeps talking about.
00:46:05 But I found this very exciting
00:46:08 because I thought these structures,
00:46:11 these little tubes which inhabit pretty well all cells,
00:46:15 it’s not just neurons,
00:46:17 apart from red blood cells,
00:46:20 they inhabit pretty well all the other cells in the body.
00:46:23 But they’re not all the same kind.
00:46:25 You get different kinds of microtubules.
00:46:28 And the ones that excited me the most,
00:46:31 this may still not be totally clear,
00:46:34 but the ones that excited me most
00:46:36 were the only ones that I knew about at the time
00:46:39 because they’re very, very symmetrical structures.
00:46:44 And I had reason to believe
00:46:45 that these very symmetrical structures
00:46:48 would be much better at preserving a quantum state,
00:46:52 quantum coherence, preserving the thing without,
00:46:55 you just need to preserve certain degrees of freedom
00:46:58 without them leaking into the environment.
00:47:01 Once they leak into the environment, you’re lost.
00:47:03 So you’ve got to preserve these quantum states at a level
00:47:08 which the state reduction process comes in
00:47:12 and that’s where I think the noncomputability comes in
00:47:17 and it’s the measurement process in quantum mechanics,
00:47:19 what’s going on.
00:47:20 So something about the measurement process
00:47:23 and what’s going on,
00:47:24 something about the structure of the microtubules,
00:47:27 your intuition says maybe there’s something here,
00:47:29 maybe this kind of structure allows
00:47:32 for the mystery of the quantum mechanics.
00:47:35 There was a much better chance, yes.
00:47:37 It just struck me that partly it was the symmetry
00:47:40 because there is a feature of symmetry
00:47:43 you can preserve quantum coherence
00:47:46 much better with symmetrical structures.
00:47:48 There’s a good reason for that.
00:47:50 And that impressed me a lot.
00:47:52 I didn’t know the difference between the A lattice
00:47:54 and B lattice at that time, which could be important.
00:47:57 Now that could even, see, which isn’t talked about much.
00:48:00 But that’s some, in some sense, details.
00:48:02 We’ve got to take a step back just to say
00:48:04 in case people are not familiar.
00:48:06 So this was called the orchestrated objective reduction
00:48:13 idea or ORCOR, which is a biological philosophy of mind
00:48:18 that postulates that consciousness originates
00:48:20 at the quantum level inside neurons.
00:48:22 So that has to do with your search for where,
00:48:25 where is it coming from?
00:48:26 So that’s counter to the notion that consciousness
00:48:29 may arise from the computation performed by the synapses.
00:48:33 Yes, I think the key point.
00:48:35 Sometimes people say it’s because it’s quantum mechanical.
00:48:40 It’s not just that.
00:48:42 See, it’s more outrageous than that.
00:48:45 You see, this is one reason I think
00:48:46 we’re so far off from it,
00:48:48 because we don’t even know the physics right.
00:48:51 You see, it’s not just quantum mechanics.
00:48:53 People say, oh, you know, quantum systems
00:48:55 and biological structures.
00:48:57 No, will you starting to see that
00:49:00 some basic biological systems does depend on quantum.
00:49:05 I mean, look, in the first place,
00:49:07 all of chemistry is quantum mechanics.
00:49:09 People got used to that, so they don’t count that.
00:49:13 So he said, let’s not count quantum chemistry.
00:49:16 We sort of got the hang of that, I think.
00:49:19 But you have quantum effects,
00:49:21 which are not just chemical, in photosynthesis.
00:49:25 And this is one of the striking things
00:49:27 in the last several years,
00:49:29 that photosynthesis seems to be a basically quantum process,
00:49:34 which is not simply chemical.
00:49:36 It’s using quantum mechanics in a very basic way.
00:49:41 So you could start saying, oh, well,
00:49:43 if photosynthesis is based on quantum mechanics,
00:49:45 why not behavior of neurons and things like that?
00:49:50 Maybe there’s something
00:49:52 which is a bit like photosynthesis in that respect.
00:49:55 But what I’m saying is even more outrageous than that,
00:49:58 because those things are talking
00:50:00 about conventional quantum mechanics.
00:50:03 Now, my argument says that conventional quantum mechanics,
00:50:07 if you’re just following the Schrodinger equation,
00:50:09 that’s still computable.
00:50:11 So you’ve got to go beyond that.
00:50:13 So you’ve got to go to where
00:50:17 quantum mechanics goes wrong in a certain sense.
00:50:21 You have to be a little bit careful about that,
00:50:23 because the way people do quantum mechanics
00:50:26 is a sort of mixture of two different processes.
00:50:32 One of them is the Schrodinger equation,
00:50:35 which is an equation Schrodinger wrote down,
00:50:38 and it tells you how the state of a system evolves.
00:50:42 And it evolves according to this equation,
00:50:44 completely deterministic,
00:50:47 but it evolves into ridiculous situations.
00:50:50 And this was what Schrodinger
00:50:51 was very much pointing out with his cat.
00:50:54 He said, you follow my equation,
00:50:55 that’s Schrodinger’s equation,
00:50:57 and you could say that you have to get a cat,
00:51:01 a cat which is dead and alive at the same time.
00:51:04 That would be the evolution of the Schrodinger equation,
00:51:07 would lead to a state, which is the cat being dead
00:51:10 and alive at the same time.
00:51:12 And he’s more or less saying, this is an absurdity.
00:51:16 People nowadays say, oh, well, Schrodinger said
00:51:18 you can have a cat which is dead, that’s not that.
00:51:20 You see, he was saying, this is an absurdity.
00:51:23 There’s something missing.
00:51:25 And that the reduction of the state
00:51:28 or the collapse of the wave function or whatever it is,
00:51:31 is something which has to be understood.
00:51:34 It’s not following the Schrodinger equation.
00:51:37 It’s not the way we conventionally do quantum mechanics.
00:51:41 There’s something more than that.
00:51:44 And it’s easy to quote authority here because Einstein,
00:51:49 at least three of the greatest physicists
00:51:52 of 20th century who were very fundamental
00:51:57 in developing quantum mechanics,
00:51:58 Einstein, one of them, Schrodinger, another,
00:52:01 Dirac, another.
00:52:03 You have to look carefully at Dirac’s writing
00:52:05 because he didn’t tend to say this out loud too much
00:52:09 because he was very cautious about what he said.
00:52:11 You find the right place and you see he says
00:52:14 quantum mechanics is a provisional theory.
00:52:18 We need something which explains
00:52:21 the collapse of the wave function.
00:52:23 We need to go beyond the theory we have now.
00:52:27 I happen to be one of the kinds of people,
00:52:29 there are many, there is a whole group of people,
00:52:31 they’re all considered to be a bit mavericks,
00:52:35 who believe that quantum mechanics needs to be modified.
00:52:38 There’s a small minority of those people,
00:52:41 which are already a minority,
00:52:42 who think that the way in which it’s modified
00:52:46 has to be with gravity.
00:52:48 And there is an even smaller minority of those people
00:52:51 who think it’s the particular way that I think it is.
00:52:53 You see.
00:52:55 So those are the quantum gravity folks.
00:52:56 But what’s…
00:52:57 You see, quantum gravity is already not this.
00:53:00 Because when you say quantum gravity,
00:53:02 what you really mean is quantum mechanics
00:53:05 applied to gravitational theory.
00:53:08 So you say, let’s take this wonderful formalism
00:53:10 of quantum mechanics and make gravity fit into it.
00:53:15 So that is what quantum gravity is meant to be.
00:53:18 Now I’m saying you’ve got to be more even handed
00:53:21 that gravity affects the structure of quantum mechanics too.
00:53:24 It’s not just you quantize gravity,
00:53:26 you’ve got to gravitate quantum mechanics.
00:53:29 And it’s a two way thing.
00:53:31 But then when do you even get started?
00:53:32 So that you’re saying that we have to figure out
00:53:35 a totally new ideas in there.
00:53:36 Exactly.
00:53:37 No, you’re stuck.
00:53:39 You don’t have a theory.
00:53:41 That’s the trouble.
00:53:42 So this is a big problem.
00:53:44 If you say, okay, well, what’s the theory?
00:53:46 I don’t know.
00:53:47 So maybe in the very early days, sort of…
00:53:49 It is in the very early days.
00:53:51 But just making this point.
00:53:52 Yes.
00:53:53 You see, Stuart Hammeroff tends to be,
00:53:55 oh, Penrose says that it’s got to be a reduction
00:53:58 of the state and so on, so let’s use it.
00:54:00 The trouble is Penrose doesn’t say that.
00:54:02 Penrose says, well, I think that we have no experiments
00:54:06 as yet, which shows that.
00:54:10 There are experiments which are being thought through
00:54:12 and which I’m hoping will be performed.
00:54:15 There is an experiment which is being developed
00:54:18 by Dirk Baumeister, who I’ve known for a long time,
00:54:22 who shares his time between Leiden in the Netherlands
00:54:25 and Santa Barbara in the US.
00:54:27 And he’s been working on an experiment
00:54:29 which could perhaps demonstrate that quantum mechanics,
00:54:35 as we now understand it, if you don’t bring in
00:54:37 the gravitational effects, it has to be modified.
00:54:42 And then there’s also experiments that are underway
00:54:45 that kind of look at the microtubule side of things
00:54:50 to see if there’s, in the biology,
00:54:52 you could see something like that.
00:54:53 Could you briefly mention it?
00:54:55 Because that’s really sort of one of the only
00:54:58 experimental attempts in the very early days
00:55:00 of even thinking about consciousness.
00:55:02 I think there’s a very serious area here,
00:55:05 which is what Stuart Hammeroff is doing,
00:55:07 and I think it’s very important.
00:55:09 One of the few places that you can really get
00:55:11 a bit of a handle on what consciousness is
00:55:14 is what turns it off.
00:55:17 And when you’re thinking about general anesthetics,
00:55:20 it’s very specific.
00:55:21 These things turn consciousness off.
00:55:24 What the hell do they do?
00:55:26 Well, Stuart and a number of people who work with him
00:55:29 and others happen to believe that the general anesthetics
00:55:34 directly affect microtubules.
00:55:36 And there is some evidence for this.
00:55:38 I don’t know how strong it is
00:55:40 and how watertight the case is,
00:55:43 but I think there is some evidence pointing
00:55:46 in that kind of direction.
00:55:49 It’s not just an ordinary chemical process.
00:55:51 There’s something quite different about it.
00:55:53 And one of the main candidates
00:55:56 is that these anesthetic gases
00:55:59 do affect directly microtubules.
00:56:02 And how strong that evidence is,
00:56:04 I wouldn’t be in a position to say,
00:56:07 but I think there is fairly impressive evidence.
00:56:10 And the point is the experiments are being undertaken,
00:56:12 which is. Yeah.
00:56:13 I mean, that is experimental.
00:56:14 You see, so it’s a very clear direction
00:56:17 where you can think of experiments
00:56:18 which could indicate whether or not
00:56:21 it’s really microtubules which the anesthetic gases
00:56:24 directly affect.
00:56:26 That’s really exciting.
00:56:27 One of the sad things is as far as I’m,
00:56:30 from my outside perspective,
00:56:31 is not many people are working on this.
00:56:34 So there’s a very, like with Stuart,
00:56:37 it feels like there’s very few people
00:56:38 are carrying the flag forward on this.
00:56:41 I think it’s not many in the sense it’s a minority,
00:56:44 but it’s not zero anymore.
00:56:46 You see, when Stuart and I were originally taught by us,
00:56:49 we were just us and a few of our friends,
00:56:52 there weren’t many people taking it,
00:56:54 but it’s grown into one of the main viewpoints.
00:56:59 There might be about four or five or six different
00:57:03 views which people hold,
00:57:06 and it’s one of them.
00:57:07 So it’s considered as one of the possible
00:57:12 lines of thinking, yes.
00:57:13 You describe physics theories
00:57:15 as falling into one of three categories,
00:57:16 the superb, the useful, or the tentative.
00:57:19 I like those words.
00:57:21 It’s a beautiful categorization.
00:57:23 Do you think we’ll ever have a superb theory
00:57:26 of intelligence and of consciousness?
00:57:29 We might.
00:57:31 We’re a long way from it.
00:57:33 I don’t think we’re even,
00:57:35 whether we’re in the tentative scale.
00:57:36 I mean, it’s…
00:57:40 You don’t think we’ve even entered the realm of tentative?
00:57:42 Probably not.
00:57:43 Yeah, that’s right.
00:57:44 Now, when you see this, it’s so controversial.
00:57:47 We don’t have a clear view
00:57:49 which is accepted by a majority.
00:57:53 I mean, you see, yeah, people,
00:57:54 most views are computational in one form or another.
00:57:57 They think it’s some, but it’s not very clear,
00:57:59 because even the IIT people who
00:58:04 think of them as computational,
00:58:06 but I’ve heard them say,
00:58:08 no, consciousness is supposed to be not computational.
00:58:09 I say, well, if it’s not computational,
00:58:10 what in the hell is it?
00:58:12 What’s going on?
00:58:14 What physical processes are going on which are that?
00:58:18 What does it mean for something to be computational then?
00:58:21 So, is…
00:58:25 Well, there has to be a process which is…
00:58:29 You see, it’s very curious
00:58:30 the way the history has developed in quantum mechanics,
00:58:34 because very early on,
00:58:35 people thought there was something to do with consciousness,
00:58:37 but it was almost the other way around.
00:58:39 You see, you have to say the Schrodinger equation
00:58:42 says all these different alternatives happen all at once,
00:58:46 and then when is it that only one of them happens?
00:58:48 Well, one of the views, which was quite commonly held
00:58:50 by a few distinguished quantum physicists,
00:58:53 that’s when a conscious being looks at the system
00:58:56 or becomes aware of it,
00:58:57 and at that point, it becomes one or the other.
00:59:01 That’s a role where consciousness
00:59:03 is somehow actively reducing the state.
00:59:07 My view is almost the exact opposite of that.
00:59:10 It’s the state reduces itself in some way which…
00:59:14 Some noncomputational way which we don’t understand,
00:59:17 we don’t have a proper theory of,
00:59:19 and that is the building block of what consciousness is.
00:59:24 So consciousness is the other way around.
00:59:26 It depends on that choice which nature makes all the time
00:59:31 when the state becomes one or the other
00:59:33 rather than the superposition of one and the other,
00:59:36 and when that happens, there is what we’re saying now,
00:59:39 an element of proto consciousness takes place.
00:59:43 Proto consciousness is, roughly speaking,
00:59:45 the building block out of which
00:59:47 actual consciousness is constructed.
00:59:50 So you have these proto conscious elements,
00:59:53 which are when the state decides
00:59:55 to do one thing or the other,
00:59:57 and that’s the thing which when organized together,
01:00:01 that’s the OR part in ORCOR, but the ORC part,
01:00:05 that’s the OR part at least one can see
01:00:08 where we’re driving at a theory.
01:00:10 You can say it’s the quantum choice
01:00:13 of going this way or that way,
01:00:14 but the ORC part, which is the orchestration of this,
01:00:17 is much more mysterious,
01:00:19 and how does the brain somehow orchestrate
01:00:23 all these individual OR processes
01:00:26 into a genuine, genuine conscious experience?
01:00:32 And it might be something that’s beautifully simple,
01:00:35 but we’re completely in the dark about.
01:00:37 Yeah, I think at the moment, that’s the thing,
01:00:40 you know, we happily put the word ORC down there
01:00:42 to say orchestrated, but that’s even more unclear
01:00:47 what that really means.
01:00:49 Just like the word material, orchestrated, who knows?
01:00:54 And we’ve been dancing a little bit
01:00:56 between the word intelligence
01:00:58 or understanding and consciousness.
01:01:00 Do you kind of see those as sitting
01:01:03 in the same space of mystery as we discussed?
01:01:05 Yes, well, you see, I tend to say
01:01:07 you have understanding and intelligence and awareness,
01:01:14 and somehow understanding is in the middle of it, you see.
01:01:21 I like to say, could you say of an entity
01:01:25 that is actually intelligent
01:01:27 if it doesn’t have the quality of understanding?
01:01:30 Now, you see, I’m using terms I don’t even know how to define,
01:01:33 but who cares?
01:01:34 I’m just relating them.
01:01:35 They’re somewhat poetic, so if I somehow understand them.
01:01:38 Yes, that’s right, we don’t, exactly.
01:01:40 But they’re not mathematical in nature.
01:01:42 Yes, you see, as a mathematician,
01:01:44 I don’t know how to define any of them,
01:01:45 but at least I can point to the connections.
01:01:47 So the idea is intelligence is something
01:01:50 which I believe needs understanding,
01:01:53 otherwise you wouldn’t say it’s really intelligence.
01:01:56 And understanding needs awareness,
01:01:59 otherwise you wouldn’t really say it’s understanding.
01:02:02 Do you say of an entity that understands something,
01:02:04 unless it’s really aware of it, you know, normal usage.
01:02:08 So there’s a three sort of awareness,
01:02:10 understanding, and intelligence.
01:02:13 And I just tend to concentrate on understanding
01:02:17 because that’s where I can say something.
01:02:19 Okay.
01:02:20 And that’s the Gödel theorem, things like that.
01:02:21 But what does it mean to be,
01:02:24 perceive the color blue or something?
01:02:26 I mean, I’m foggiest.
01:02:28 It’s a much more difficult question.
01:02:31 I mean, is it the same if I see a color blue and you see it?
01:02:34 If you’re somebody with this condition,
01:02:36 what’s it called then?
01:02:38 Or where you assign a sound to a color.
01:02:41 Yeah, yeah, that’s right.
01:02:42 You get colors and sounds mixed up.
01:02:44 And that sort of thing.
01:02:45 I mean, an interesting subject.
01:02:49 But from the physics perspective,
01:02:50 from the fundamentals perspective, we don’t.
01:02:53 I think we’re way off having much understanding
01:02:56 what’s going on there.
01:02:57 In your 2010 book, Cycles of Time,
01:03:01 you suggest that another universe may have existed
01:03:04 before the Big Bang.
01:03:06 Can you describe this idea?
01:03:08 First of all, what is the Big Bang?
01:03:10 Sounds like a funny word.
01:03:13 And what may have been there before it?
01:03:17 Yes.
01:03:17 Just as a matter of terminology,
01:03:19 I don’t like to call it another universe.
01:03:21 Because when you have another universe,
01:03:23 you think of it kind of quite separate from us.
01:03:25 But these things, they’re not separate.
01:03:28 Now the Big Bang, conventional theory.
01:03:31 You see, I was actually brought up
01:03:34 in the sense of when I started getting
01:03:35 interested in cosmology,
01:03:36 there was a thing called the Steady State Model,
01:03:39 which was sort of philosophically very interesting.
01:03:41 And there wasn’t a Big Bang in that theory.
01:03:43 But somehow, new material was created all the time
01:03:46 in the form of hydrogen,
01:03:48 and the universe kept on expanding, expanding, expanding,
01:03:50 and there was room for more hydrogen.
01:03:52 It was a rather philosophically nice picture.
01:03:54 It was disproved when the Big Bang,
01:03:59 well, when I say the Big Bang,
01:04:01 this was theoretically discovered
01:04:04 by people trying to solve Einstein’s equations
01:04:07 and apply it to cosmology.
01:04:09 Einstein didn’t like the idea.
01:04:10 He liked a universe which was there all the time.
01:04:14 And he had a model which was there all the time.
01:04:16 But then there was this discovery,
01:04:19 accidental discovery, very important discovery,
01:04:22 of this microwave background.
01:04:25 And if you, there’s the crackle on your television screen
01:04:28 which is already sensing this microwave background,
01:04:32 which is coming at us from all directions.
01:04:35 And you can trace it back and back and back and back.
01:04:37 And it came from a very early stage of the universe.
01:04:41 Well, it’s part of the Big Bang theory.
01:04:43 The Big Bang theory was when people tried
01:04:45 to solve Einstein’s equations.
01:04:47 They really found you had to have this initial state
01:04:50 where the universe, it used to be called
01:04:52 the primordial atom and things like this.
01:04:55 There’s Friedman and Lemaitre.
01:04:58 Friedman was a Russian, Lemaitre was a Belgian.
01:05:01 And they independently, well, basically Friedman first.
01:05:04 And Lemaitre talked about the initial state,
01:05:08 which is a very, very concentrated initial state
01:05:11 which seemed to be the origin of the universe.
01:05:13 Primordial atom.
01:05:14 Primordial atom is what he called it, yes.
01:05:17 And then it became, well, Fred Hoyle used the term
01:05:20 Big Bang in a kind of derogatory sense.
01:05:22 Just like with the Schrodinger and the cats, right?
01:05:25 Yes, it’s like sort of got picked up on
01:05:28 whereas it wasn’t his intention originally.
01:05:30 But then the evidence piled up and piled up.
01:05:33 And one of my friends and I learned a lot from him
01:05:36 when I was in Cambridge was Dennis Sharma.
01:05:38 He was a great proponent of steady state.
01:05:40 And then he got converted.
01:05:41 He said, no, I’m sorry.
01:05:43 I had a great respect for him.
01:05:44 He went around lecturing and said, I was wrong.
01:05:46 The steady state model doesn’t work.
01:05:48 There was this Big Bang.
01:05:50 And this microwave background that you see,
01:05:53 okay, it’s not actually quite the Big Bang.
01:05:55 When I say not quite, it’s about 380,000 years
01:05:58 after the Big Bang, but that’s what you see.
01:06:01 But then you have to have had this Big Bang before it
01:06:03 in order to make the equations work.
01:06:05 And it works beautifully except for one little thing,
01:06:09 which is this thing called inflation,
01:06:11 which people had to put into it to make it work.
01:06:14 When I first heard of it, I didn’t like it at all.
01:06:16 What’s inflation?
01:06:17 Inflation is that in the first,
01:06:20 I’m gonna give you a very tiny number.
01:06:22 Think of a second.
01:06:23 That’s not very long.
01:06:25 Now I’m gonna give you a fraction of a second,
01:06:26 one over a number.
01:06:29 This number has 32 digits between,
01:06:34 well, let’s say between 36 and 32 digits.
01:06:37 Tiny, tiny time between those two tiny,
01:06:41 ridiculous seconds, fraction of a second,
01:06:44 the universe was supposed to have expanded
01:06:46 in this exponential way, an enormous way.
01:06:49 For no apparent reason, you had to invent
01:06:52 a particular thing called the inflaton field
01:06:54 to make it do it.
01:06:56 And I thought this is completely crazy.
01:06:58 There are reasons why people stuck with this idea.
01:07:01 You see, the thing is that I formed my model
01:07:04 for reasons which are very fundamental, if you like.
01:07:07 It has to do with this very fundamental principle,
01:07:10 which is known as the second law of thermodynamics.
01:07:13 The second law of thermodynamics says more or less,
01:07:16 things get more and more random as time goes on.
01:07:20 Now, another way of saying exactly the same thing
01:07:22 is things get less and less random.
01:07:24 As things go back, as you go back in time,
01:07:26 they get less and less random.
01:07:28 They go back and back and back and back.
01:07:30 And the earliest thing you can directly see
01:07:32 is this microwave background.
01:07:34 What’s one of the most striking features of it
01:07:37 is that it’s random.
01:07:39 It has this, what you call this spectrum of,
01:07:43 which is what’s called the Planck spectrum,
01:07:46 of frequencies, different intensities
01:07:48 for different frequencies.
01:07:49 And it’s this wonderful curve due to Max Planck.
01:07:53 And what’s it telling you?
01:07:54 It’s telling you that the entropy is at a maximum.
01:07:58 Started off at a maximum and it’s going up ever since.
01:08:02 I call that the mammoth in the room.
01:08:03 I mean, it’s a paradox.
01:08:05 A mammoth, yeah, it is.
01:08:07 And so people, why don’t cosmologists worry about this?
01:08:10 So I worried about it.
01:08:11 And then I thought, well, it’s not really a paradox
01:08:14 because you’re looking at matter and radiation
01:08:19 at a maximum entropy state.
01:08:20 What you’re not seeing directly in that is the gravitation.
01:08:25 It’s gravitation, which is not thermalized.
01:08:28 The gravitation was very, very low entropy.
01:08:32 And it’s low entropy by the uniformity.
01:08:34 And you see that in the microwave too.
01:08:35 It’s very uniform over the whole sky.
01:08:38 I’m compressing a long story
01:08:39 into a very short few sentences.
01:08:40 And doing a great job, yeah.
01:08:42 So what I’m saying is that there’s a huge puzzle.
01:08:45 Why was gravity in this very low entropy state,
01:08:50 very highly organized state, everything else was all random?
01:08:55 And that to me was the biggest problem in cosmology.
01:08:59 The biggest problem, nobody seems to even worry about it.
01:09:02 People say they solved all the problems
01:09:04 and they don’t even worry about it.
01:09:05 They think inflation solves it.
01:09:07 It doesn’t, it can’t.
01:09:08 Because it’s just that…
01:09:12 Just to clarify, that was your problem
01:09:14 with the inflation describing some aspect
01:09:18 of the moments right after the Big Bang?
01:09:20 Inflation is supposed to stretch it out
01:09:22 and make it all uniform, you see.
01:09:23 It doesn’t do it because it can only do it
01:09:25 if it’s uniform already at the beginning.
01:09:27 It’s, you just have to look at,
01:09:28 I can’t go into the details, but it doesn’t solve it.
01:09:31 And it was completely clear to me it doesn’t solve it.
01:09:33 But where does the conformal cyclic cosmology
01:09:36 of starting to talk about something before
01:09:40 that singular and the Big Bang?
01:09:41 I was just thinking to myself,
01:09:44 how boring this universe is going to be.
01:09:47 You’ve got this exponential expansion.
01:09:49 This was discovered early in the,
01:09:51 in this century, 21st century.
01:09:56 People discovered that these supernova exploding stars
01:10:01 showed that the universe is actually undergoing
01:10:04 this exponential expansion.
01:10:07 So it’s a self similar expansion.
01:10:10 And it seems to be a feature of this term
01:10:14 that Einstein introduced into his cosmology
01:10:17 for the wrong reason.
01:10:18 He wanted a universe that was static.
01:10:20 He put this new term into his cosmology.
01:10:23 To make it make sense,
01:10:24 it’s called the cosmological constant.
01:10:26 And then when he got convinced
01:10:28 that the universe had a Big Bang,
01:10:29 he retracted it complaining this was his greatest blunder.
01:10:33 The trouble is it wasn’t a blunder.
01:10:34 It was actually right, very ironic.
01:10:37 And so the universe seems to be behaving
01:10:40 with this cosmological constant.
01:10:41 Okay, so this universe is expanding and expanding.
01:10:45 What’s going to happen in the future?
01:10:46 Well, it gets more and more boring for a while.
01:10:48 What’s the most interesting thing in the universe?
01:10:50 Well, there’s black holes.
01:10:51 The black holes more or less gulp down
01:10:53 entire clusters of galaxies.
01:10:56 The cluster, it’ll swallow up most of our galaxy.
01:10:59 We will run into our Andromeda galaxy’s black hole.
01:11:01 That black hole will swallow our one.
01:11:03 They’ll get bigger and bigger
01:11:04 and they’ll basically swallow up
01:11:07 the whole cluster of galaxies, gulp it all down.
01:11:10 Pretty well all, most of it, maybe not all, most of it.
01:11:13 Okay, then that’ll happen to,
01:11:15 there’ll be just these black holes around.
01:11:16 Pretty boring, but still not as boring as it’s gonna get.
01:11:19 It’s gonna get more boring because these black holes,
01:11:21 you wait and you wait and you wait and you wait
01:11:24 an unbelievable length of time
01:11:26 and Hawking’s black hole evaporation starts to come in.
01:11:30 And the black holes, you just, it’s incredibly tedious.
01:11:34 Finally evaporate away.
01:11:36 Each one goes away, disappears with a pop at the end.
01:11:39 What could be more boring?
01:11:40 It was boring then, now this is really boring.
01:11:43 There’s nothing, not even black holes.
01:11:46 Universe gets colder and colder and colder and colder.
01:11:48 And I thought, this is very, very boring.
01:11:52 Now that’s not science, is it?
01:11:54 But it’s emotional.
01:11:56 So I thought, who’s gonna be bored by this universe?
01:11:59 Not us, we won’t be around.
01:12:01 It’ll be mostly photons running around.
01:12:04 And what the photons do, they don’t get bored
01:12:06 because it’s part of relativity, you see.
01:12:08 It’s not really that they don’t experience anything.
01:12:10 That’s not the point.
01:12:12 Photons get right out to infinity
01:12:15 without experience any time.
01:12:18 It’s the way relativity works.
01:12:21 And this was part of what I used to do in my old days
01:12:23 when I was looking at gravitational radiation
01:12:25 and how things behaved to infinity.
01:12:27 Infinity is just like another place.
01:12:30 You can squash it down.
01:12:31 As long as you don’t have any mass in the world,
01:12:34 infinity is just another place.
01:12:36 The photons get there, the gravitons get there.
01:12:39 What do they get?
01:12:40 They’ve run into infinity.
01:12:42 They say, well, now I’m here, what do I?
01:12:44 There’s something on the other side, is there?
01:12:46 The usual view, it’s just a mathematical notion.
01:12:48 There’s nothing on the other side.
01:12:49 That’s just the boundary of it.
01:12:51 A nice example is this beautiful series of pictures
01:12:54 by the Dutch artist MC Escher.
01:12:57 You may know them.
01:12:58 The one’s called Circle Limits.
01:12:59 They’re a very famous one with the angels and the devils.
01:13:02 And you can see them crowding and crowding
01:13:04 and crowding up to the edge.
01:13:06 Now, the kind of geometry that these angels and devils
01:13:09 inhabit, that’s their infinity.
01:13:12 But from our perspective, infinity is just a place.
01:13:16 Okay, there is…
01:13:17 I’m sorry, can you just take a brief pause?
01:13:20 Yes.
01:13:21 In just the words you’re saying,
01:13:22 infinity is just a place.
01:13:24 So for the most part, infinity, sort of even just going back,
01:13:28 infinity is a mathematical concept.
01:13:31 I think this is one of the things…
01:13:32 You think there’s an actual physical manifest…
01:13:35 In which way does infinity ever manifest itself
01:13:38 in our physical universe?
01:13:40 Well, it does in various places.
01:13:41 You see, it’s a thing that if you’re not a mathematician,
01:13:44 you think, oh, infinity, I can’t think about that.
01:13:46 Mathematicians think about affinity all the time.
01:13:48 They get used to the idea and they just play around
01:13:50 with different kinds of infinities
01:13:52 and it becomes no problem.
01:13:54 But you just have to take my word for it.
01:13:57 Now, one of the things is,
01:13:58 you see, you take a Euclidean geometry.
01:14:00 Well, it just keeps on going and it goes out to infinity.
01:14:04 Now, there’s other kinds of geometry
01:14:06 and this is what’s called hyperbolic geometry.
01:14:09 It’s a bit like Euclidean geometry,
01:14:10 it’s a little bit different.
01:14:12 It’s like what Escher was trying to describe
01:14:14 in his angels and devils.
01:14:17 And he learned about this from Coxeter
01:14:19 and he think that’s a very nice thing.
01:14:21 That’s why I represent this infinity
01:14:24 to this kind of geometry.
01:14:25 So it’s not quite Euclidean geometry,
01:14:27 it’s a bit like it,
01:14:28 that the angels and the devils inhabit.
01:14:30 And their infinity, by this nice transformation,
01:14:34 you squash their infinity down
01:14:36 so you can draw it as this nice circle boundary
01:14:39 to their universe.
01:14:42 Now, from our outside perspective,
01:14:44 we can see their infinity as this boundary.
01:14:47 Now, what I’m saying is that it’s very like that.
01:14:50 The infinity that we might experience
01:14:53 like those angels and devils in their world
01:14:56 can be thought of as a boundary.
01:14:59 Now, I found this a very useful way
01:15:01 of talking about radiation,
01:15:03 gravitational radiation and things like that.
01:15:07 It was a trick, mathematical trick.
01:15:10 So now what I’m saying is that
01:15:11 that mathematical trick becomes real.
01:15:14 That somehow, the photons,
01:15:17 they need to go somewhere
01:15:19 because from their perspective,
01:15:22 infinity is just another place.
01:15:25 Now, this is a difficult idea to get your mind around.
01:15:28 So that’s one of the reasons cosmologists
01:15:31 are finding a lot of trouble taking me seriously.
01:15:34 But to me, it’s not such a wild idea.
01:15:37 What’s on the other side of that infinity?
01:15:39 You have to think, why am I allowed to think of this?
01:15:43 Why am I allowed to think of this?
01:15:45 Because photons don’t have any mass.
01:15:48 And we in physics have beautiful ways of measuring time.
01:15:53 There are incredibly precise clocks,
01:15:55 atomic and nuclear clocks, unbelievably precise.
01:15:59 Why are they so precise?
01:16:01 Because of the two most famous equations
01:16:04 of 20th century physics.
01:16:06 One of them is Einstein’s E equals MC squared.
01:16:10 What’s that tell us?
01:16:11 Energy and mass are equivalent.
01:16:14 The other one is even older than that,
01:16:16 still 20th century, only just.
01:16:18 Max Planck, E equals h nu.
01:16:22 Nu is a frequency,
01:16:24 h is a constant, again, like C.
01:16:26 E is energy.
01:16:28 Energy and frequency are equivalent.
01:16:31 Put the two together,
01:16:33 energy and mass are equivalent, Einstein.
01:16:34 Energy and frequency are equivalent, Max Planck.
01:16:37 Put the two together, mass and frequency are equivalent.
01:16:41 Absolutely basic physical principle.
01:16:44 If you have a massive entity, a massive particle,
01:16:47 it is a clock with a very, very precise frequency.
01:16:53 It’s not, you can’t directly use it,
01:16:55 you have to scale it down.
01:16:56 So your atomic and nuclear clocks,
01:16:57 but that’s the basic principle.
01:16:59 You scale it down to something you can actually perceive.
01:17:02 But it’s the same principle.
01:17:03 If you have mass, you have beautiful clocks.
01:17:07 But the other side of that coin is,
01:17:10 if you don’t have mass, you don’t have clocks.
01:17:14 If you don’t have clocks, you don’t have rulers.
01:17:18 You don’t have scale.
01:17:20 So you don’t have space and time.
01:17:21 You don’t have a measure of the scale of space and time.
01:17:24 Oh, scale of space and time.
01:17:26 You do have the structure,
01:17:29 what’s called the conformal structure.
01:17:30 You see, it’s what the angels and devils have.
01:17:33 If you look at the eye of the devil,
01:17:35 no matter how close to the boundary it is,
01:17:36 it has the same shape, but it has a different size.
01:17:40 So you can scale up and you can scale down,
01:17:43 but you mustn’t change the shape.
01:17:46 So it’s basically the same idea,
01:17:48 but applied to space time now.
01:17:50 In the very remote future,
01:17:52 you have things which don’t measure the scale,
01:17:55 but the shape, if you like, is still there.
01:17:58 Now that’s in the remote future.
01:17:59 Now I’m gonna do the exact opposite.
01:18:01 Now I’m gonna go way back into the Big Bang.
01:18:04 Now as you get there, things get hotter and hotter,
01:18:08 denser and denser.
01:18:10 What’s the universe dominated by?
01:18:13 Particles moving around almost with the speed of light.
01:18:16 When they get almost with the speed of light,
01:18:19 okay, they begin to lose the mass too.
01:18:21 So for completely opposite reason,
01:18:24 they lose the sense of scale as well.
01:18:26 So my crazy idea is the Big Bang and the remote future,
01:18:32 they seem completely different.
01:18:33 One is extremely dense, extremely hot.
01:18:36 The other is very, very rarefied and very, very cold.
01:18:39 But if you squash one down by this conformal scaling,
01:18:42 you get the other.
01:18:44 So although they look and feel very different,
01:18:48 they’re really almost the same.
01:18:50 The remote future on the other side,
01:18:53 I’m claiming is that where do the photons go?
01:18:55 They go into the next Big Bang.
01:18:58 You’ve got to get your mind around that crazy idea.
01:19:01 Taking a step on the other side of the place
01:19:03 that is infinity.
01:19:05 Okay, but.
01:19:07 So I’m saying the other side of our Big Bang,
01:19:09 now I’m going back into the Big Bang.
01:19:10 Back, backwards.
01:19:11 There was the remote future of a previous eon.
01:19:13 Previous eon.
01:19:15 And what I’m saying is that previous eon,
01:19:17 there are signals coming through to us,
01:19:20 which we can see and which we do see.
01:19:23 And these are both signals,
01:19:25 the two main signals are to do with black holes.
01:19:29 One of them is the collisions between black holes.
01:19:33 And as they spiral into each other,
01:19:35 they release a lot of energy
01:19:37 in the form of gravitational waves.
01:19:39 Those gravitational waves get through
01:19:42 in a certain form into the next eon.
01:19:44 That’s fascinating that there’s some,
01:19:46 I mean, maybe you can correct me if I’m wrong,
01:19:49 but that means that some information can travel
01:19:52 from another eon.
01:19:53 Exactly.
01:19:54 That is fascinating.
01:19:58 I mean, I’ve seen somewhere described
01:20:01 sort of the discussion of the Fermi Paradox,
01:20:05 you know, that if there’s intelligent life.
01:20:08 Yes.
01:20:09 Being, you know, communication immediately takes you there.
01:20:12 So.
01:20:13 We have a paper, I have my colleague,
01:20:16 Vahid Guzajan, who I worked with on these ideas for a while.
01:20:19 We have a crazy paper on that, yes.
01:20:21 So.
01:20:22 Looking at the Fermi Paradox, yes.
01:20:23 Right, so if the universe is just cycling
01:20:25 over and over and over,
01:20:27 punctuated by the, punctuated the singularity
01:20:31 of the Big Bang,
01:20:32 and then intelligent or any kind of intelligent systems
01:20:36 can communicate through from eon to eon,
01:20:39 why haven’t we heard anything from our alien friends?
01:20:44 Because we don’t know how to look.
01:20:46 That’s fundamentally the reason, is we.
01:20:48 I don’t know, you see, it’s speculation.
01:20:51 I mean, the SETI program is a reasonable thing to do,
01:20:55 but still speculation.
01:20:56 It’s trying to say, okay, maybe not too far away
01:21:01 was a civilization which got there first, before us,
01:21:05 early enough that they could send us signals,
01:21:08 but how far away would you need to go before,
01:21:11 I mean, I don’t know, we have so little knowledge
01:21:13 about that, we haven’t seen any signals yet,
01:21:15 but it’s worth looking, it’s worth looking.
01:21:18 What I’m trying to say, here’s another possible place
01:21:21 where you might look.
01:21:22 Now you’re not looking at civilizations
01:21:24 which got there first,
01:21:26 you’re looking at those civilizations
01:21:27 which were so successful,
01:21:29 probably a lot more successful than they’re likely to be
01:21:32 by the looks of things,
01:21:34 which knew how to handle their own global warming
01:21:38 or whatever it is and to get through it all
01:21:40 and to live to a ripe old age in the sense of a civilization
01:21:45 to the extent that they could harness signals
01:21:49 that they could propagate through for some reason
01:21:52 of their own desires, whatever we wouldn’t know
01:21:55 to other civilizations
01:21:57 which might be able to pick up the signals.
01:22:00 But what kind of signals would they be?
01:22:01 I haven’t the foggiest.
01:22:05 Let me ask the question.
01:22:06 Yes.
01:22:07 What to you is the most beautiful idea
01:22:09 in physics or mathematics or the art
01:22:12 at the intersection of the two?
01:22:15 I’m gonna have to say complex analysis.
01:22:17 I might’ve said infinities.
01:22:19 And one of the most single, most beautiful idea
01:22:22 I think was the fact that you can have
01:22:24 infinities of different sizes and so on.
01:22:26 But that’s in a way, I think complex analysis.
01:22:30 It’s got so much magic in it.
01:22:32 It’s a very simple idea.
01:22:36 You take these, you take numbers,
01:22:39 you take the integers and then you fill them up
01:22:41 into the fractions and the real numbers.
01:22:44 You imagine you’re trying to measure a continuous line
01:22:46 and then you think of how you can solve equations.
01:22:50 Then what about X squared equals minus one?
01:22:54 Well, there’s no real number which has to satisfy that.
01:22:57 So you have to think of, well, there’s a number called I.
01:23:01 You think you invent it.
01:23:02 Well, in a certain sense, it’s there already.
01:23:05 But this number, when you add that square root
01:23:07 of minus one to it,
01:23:08 you have what’s called the complex numbers.
01:23:10 And they’re an incredible system.
01:23:13 If you like, you put one little thing in,
01:23:15 you put square root of minus one in
01:23:17 and you get how much benefit out of it.
01:23:20 All sorts of things that you’d never imagined before.
01:23:23 And it’s that amazing, all hiding there
01:23:27 in putting that square root of minus one in.
01:23:30 I think that’s the most magical thing I’ve seen
01:23:32 in mathematics or physics.
01:23:34 And it’s in quantum mechanics.
01:23:35 And in quantum mechanics.
01:23:36 You see, it’s there already.
01:23:38 You might think, what’s it doing there?
01:23:39 Okay, just a nice beautiful piece of mathematics.
01:23:41 And then suddenly we see, nope.
01:23:44 It’s the very crucial basis of quantum mechanics.
01:23:47 It’s there and the way the world works.
01:23:49 So on the question of whether math
01:23:50 is discovered or invented,
01:23:52 it sounds like you may be suggesting
01:23:54 that partially it’s possible
01:23:56 that math is indeed discovered.
01:23:57 Oh, absolutely, yes.
01:23:59 No, it’s more like archeology than you might think.
01:24:02 Yes, yes.
01:24:03 So let me ask the most ridiculous,
01:24:06 maybe the most important question.
01:24:08 What is the meaning of life?
01:24:11 What gives your life fulfillment, purpose,
01:24:15 happiness, and meaning?
01:24:16 Why do you think we’re here on this?
01:24:18 Given all the big bang and the infinities of photons
01:24:20 that we’ve talked about.
01:24:21 All I would say, I think it’s not a stupid question.
01:24:26 I mean, there are some people, you know,
01:24:28 many of my colleagues who are scientists,
01:24:29 and they say, well, that’s a stupid question,
01:24:31 meaning, yeah, well, we’re just here
01:24:32 because things came together and produced life
01:24:35 and so what.
01:24:37 I think there’s more to it.
01:24:39 But what there is that’s more to it,
01:24:41 I have really much idea.
01:24:43 And it might be somehow connected
01:24:44 to the mechanisms of consciousness
01:24:46 that we’ve been talking about, the mystery there.
01:24:49 It’s connected with all sorts of, yeah,
01:24:51 I think these things are tied up in ways which are,
01:24:54 you see, I tend to think the mystery of consciousness
01:24:56 is tied up with the mystery of quantum mechanics
01:25:00 and how it fits in with the classical world,
01:25:04 and that’s all to do with the mystery of complex numbers.
01:25:08 And there are mysteries there
01:25:10 which look like mathematical mysteries,
01:25:13 but they seem to have a bearing
01:25:15 on the way the physical world operates.
01:25:18 We’re scratching the surface.
01:25:20 We have a long, huge way to go
01:25:22 before we really understand that.
01:25:24 And it’s a beautiful idea that the depth,
01:25:28 the mathematical depth could be discovered,
01:25:30 and then there’s tragedies of ghettos
01:25:32 and completeness along the way
01:25:34 that we’ll have to somehow figure our ways around.
01:25:37 Yeah.
01:25:38 So, Roger, it was a huge honor to talk to you.
01:25:42 Thank you so much for your time today.
01:25:43 It’s been my pleasure.
01:25:44 Thank you.
01:25:46 Thanks for listening to this conversation
01:25:47 with Roger Penrose,
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01:26:14 And now let me leave you with some words of wisdom
01:26:17 that Roger Penrose wrote in his book,
01:26:19 The Emperor’s New Mind.
01:26:21 Beneath all this technicality is the feeling
01:26:24 that it is indeed, quote unquote, obvious
01:26:28 that the conscious mind cannot work like a computer,
01:26:31 even though much of what is involved
01:26:33 in mental activity might do so.
01:26:35 This is the kind of obviousness that a child can see,
01:26:39 though the child may later in life become browbeaten
01:26:42 into believing that the obvious problems
01:26:44 are quote unquote, non problems,
01:26:47 to be argued into nonexistence by careful reasoning
01:26:51 and clever choices of definition.
01:26:53 Children sometimes see things clearly
01:26:56 that are obscured in later life.
01:26:59 We often forget the wonder that we felt as children
01:27:02 when the cares of the quote unquote, real world
01:27:05 had begun to settle on our shoulders.
01:27:07 Children are not afraid to pose basic questions
01:27:10 that may embarrass us as adults to ask.
01:27:13 What happens to each of our streams of consciousness
01:27:15 after we die?
01:27:17 Where was it before we were born?
01:27:19 Might we become or have been someone else?
01:27:23 Why do we perceive it all?
01:27:25 Why are we here?
01:27:26 Why is there a universe here at all
01:27:28 in which we can actually be?
01:27:30 These are puzzles that tend to come
01:27:32 with the awakenings of awareness in any of us
01:27:35 and no doubt with the awakening of self awareness
01:27:39 within whichever creature or other entity it first came.
01:27:43 Thank you for listening and hope to see you next time.