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Roger Penrose: Physics of Consciousness and the Infinite Universe | Lex Fridman Podcast #85


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The following is a conversation with Roger Panrose, physicist, mathematician, and philosopher
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at University of Oxford.
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He has made fundamental contributions in many disciplines, from the mathematical physics
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of general relativity and cosmology, to the limitations of a computational view of consciousness.
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In his book, The Emperor's New Mind, Roger writes that, quote,
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Children are not afraid to pose basic questions that may embarrass us as adults to ask.
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In many ways, my goal with this podcast is to embrace the inner child that is not constrained
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by how one should behave, speak, and think in the adult world.
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Roger is one of the most important minds of our time, so it's truly a pleasure and an
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honor to talk with him.
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This conversation was recorded before the outbreak of the pandemic.
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For everyone feeling the medical, psychological, and financial burden of the crisis, I'm sending
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love your way.
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Stay strong.
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We're in this together.
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We'll beat this thing.
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This is the Artificial Intelligence Podcast.
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If you enjoy it, subscribe on YouTube, review it with five stars on Apple Podcasts, support
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it on Patreon, or simply connect with me on Twitter at Lex Freedman, spelled FRIDMAN.
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As usual, I'll do a few minutes of ads now and never any ads in the middle that can break
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Get it at expressvpn.com slash Lex pod to get a discount and to support this podcast.
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podcast.
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And now here's my conversation with Roger Penrose.
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You mentioned in conversation with Eric Weinstein on the portal podcast that 2001 Space Odyssey
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is your favorite movie.
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Which aspect, if you could mention, of its representation of artificial intelligence,
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science, engineering connected with you?
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There are all sorts of scenes there, which are so amazing.
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And how the science was so well done.
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I mean, people say, you know, Interstellar is this amazing movie, which is the most scientific
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movie.
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I thought it's not a patch on 2001.
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I mean, 2001, they really went into all sorts of details regarding, you know, getting the
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free fall, well done and everything.
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I thought it was extremely well done.
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So just the details were mesmerizing.
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I don't know.
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So things like the scene where at the beginning they have these sort of human ancestors, which
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is sort of, right, sort of apes, apes becoming monolith.
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Yes.
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And well, it's the one where he throws the bone up into the air and then it becomes this.
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I mean, that's an amazing sequence there.
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What do you make of the monolith?
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Does it have any scientific or philosophical meaning to you?
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This kind of thing that sparks innovation?
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Not really.
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That comes from Arthur C. Clarke.
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I was always a great fan of Arthur C. Clarke.
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So it's just a nice plot device.
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Yeah.
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Oh, that plot is excellent.
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Yes.
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Yeah.
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And then Halzen decides to get rid of the astronauts because he, it, she believes that
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they will interfere with the mission.
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That's right.
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Yeah.
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Well, there you are.
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It's this view.
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I don't know whether I disagree, but because in a certain sense it was telling you it's
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wrong.
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See, the machine seemed to think it was superior to the human and so it was entitled to get
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rid of the human beings and run the show itself.
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Well, do you think Hal did the right thing?
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Do you think Hal's flawed, evil, or if we think about systems like Hal, would we want
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Hal to do the same thing in the future?
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What was the flaw there?
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Well, you're basically touching on questions.
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You see, it's one supposed to believe that Hal was actually conscious.
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I mean, it was played rather that way as though Hal was a conscious being.
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Because Hal showed some pain, some cognizant, Hal appeared to be cognizant of what it means
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to die and therefore had an inkling of consciousness.
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Yeah.
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I mean, I'm not sure that aspect of it was made completely clear whether Hal was really
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a just a very sophisticated computer, which really didn't actually have these feelings
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and somehow, but you're right.
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It didn't like the idea of being turned off.
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How does it change things if Hal was or wasn't conscious?
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Well, it might say that it would be wrong to turn it off if it was actually conscious.
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I mean, these questions arise if you think, I mean, AI, one of the ideas, it's sort of
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a mixture in a sense.
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You say, if it's trying to do everything a human can do and if you take the view that
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consciousness is something which would come along when the computer is sufficiently complicated,
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sufficiently whatever criteria you use to characterize its consciousness in terms of
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some computational criterion.
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So how does consciousness change our evaluation of the decision that Hal made?
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Yes.
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I guess I was trying to say that people are a bit confused about this because if they
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say these machines will become conscious, but just simply because it's a degree of computation
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and when you get beyond that certain degree of computation, it will become conscious,
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then of course you have all these problems.
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I mean, you might say, well, one of the reasons you're doing AI is because you understand
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a device out to some distant planet and you don't want to send a human out there because
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then you'd have to bring it back again and that costs you far more than just sending
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it there and leaving it there.
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But if this device is actually a conscious entity, then you have to face up to the fact
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that that's immoral.
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And so the mere fact that you're making some AI device and thinking that removes your responsibility
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to it would be incorrect.
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And so this is a sound of flaw in that kind of viewpoint.
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I'm not sure how people who take it very seriously, I mean, I had this curious conversation
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with, I'm going to forget names and I'm afraid because this is what happens to me at the
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wrong moment, Hofstadter, Douglas Hofstadter.
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Douglas Hofstadter, yeah.
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And he'd written this book, I wish I liked, I thought it was a fantastic book.
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But I didn't agree with his conclusion from Gödel's theorem, I think he got it wrong,
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you see.
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Well, I'll just tell you my story, you see, because I'd never met him.
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And then I knew I was going to meet him.
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At the occasion, I realized he was coming and he wanted to talk to me and I said, that's
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fine.
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And I thought in my mind, well, I'm going to paint him into a corner, you see, because
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I'll use his arguments to convince him that certain numbers are conscious, you know, some
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integers, large enough integers are actually conscious.
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And this was going to be my reductive, I'd absurd them.
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And so I started having this argument with him, he simply leapt into the corner, he didn't
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even need to be painted into it, he took the view that certain numbers were conscious.
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I thought that was the reductive, I'd absurd them, but he seemed to think it was perfectly
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reasonable point of view.
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Without the absurd them there, yes, interesting.
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But the thing you mentioned about how is the intuition that a lot of the people, at least
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in the artificial intelligence world had and have, I think, they don't make it explicit,
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but that if you increase the power of computation, naturally consciousness will emerge.
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Yes, I think that's what they think.
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But basically that's because they can't think of anything else.
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Well, that's right.
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And so it's a reasonable thing, I mean, you think what the brain do does do a lot of computation.
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I think most of what you actually call computation is done by the cerebellum.
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I mean, this is one of the things that people don't much mention.
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I mean, I come to this subject from the outside and certain things strike me, which you hardly
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ever hear mentioned.
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I mean, you hear mentioned about the left right business, the move your right arm, that's
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your left side of the brain and so on and all that sort of stuff.
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And it's more than that.
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If you have these plots of different parts of the brain, there are two of these things
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called the homunculi, which you see these pictures of a distorted human figure and showing
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different parts of the brain controlling different parts of the body.
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And it's not simply things like, okay, the right hand is controlled and both sensory
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and motor on the left side, left hand on the right side, it's more than that.
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Vision is at the back basically, your feet at the top, and so it's about the worst organization
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you could imagine.
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Right, yeah.
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So it can't just be a mistake in nature, there's something going on there.
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And this is made more pronounced when you think of the cerebellum.
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The cerebellum has, when I was first thinking about these things, I was told that it had
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half as many neurons or something like that, comparable.
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And now they tell me it's got far more neurons than the cerebrum.
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The cerebrum is this sort of convoluted thing at the top, people always talk about cerebellum
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is this thing, just looks a bit like a ball of wool, right at the back underneath them.
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It's got more neurons, it's got more connections, computationally, it's got much more going
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on than this, from the cerebrum.
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But as far as we know, although it's slightly controversial, the cerebellum is entirely
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unconscious.
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So the actions, you have a pianist who plays an incredible piece of music and think of,
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and he moves his little finger into this little key to get it hit at just the right moment.
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Does he or she consciously will that movement?
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No.
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Okay, the consciousness is coming in, it's probably to do with the feeling of the piece
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of music is being performed and that sort of thing, which is going on, but the details
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and what's going on are controlled.
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I would think almost entirely by the cerebellum.
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That's where you have this precision and the really detailed, once you get, I mean, you
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think of a tennis player or something, does that tennis player think exactly which muscles
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should be moved in what direction and so on, no, of course not, but he or she will maybe
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think, well, if the ball is angled in such a way in that corner, that will be tricky
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for the opponent.
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And the details of that are all done largely with the cerebellum, that's where all the
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precise motions, but it's unconscious.
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So why is it interesting to you that so much computation is done in the cerebellum and
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yet is unconscious?
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Because it's the view that somehow it's computation, which is producing the consciousness.
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And here you have an incredible amount of computation going on, and as far as we know,
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it's completely unconscious.
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So why, what's the difference?
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And I think it's an important thing, what's the difference?
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Why is the cerebrum, all this very peculiar stuff that very hard to see on a computational
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perspective, like having everything have to cross over under the other side and do something
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which looks completely inefficient.
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And you've got funny things like the frontal lobe and the, what do we call the lobes?
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And the place where they come together, you have the different parts, the control, you
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see one to do with motor and the other to do with sensory.
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And they sort of opposite each other rather than being connected by, it's not as though
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you've got electrical circuits, there's something else going on there.
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So it's just the idea that it's like a complicated computer, it just seems to me to be completely
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missing the point.
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There must be a lot of computation going on, but the cerebellum seems to be much better
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at doing that than the cerebrum is.
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So for sure, I think what explains it is like half hope and half we don't know what's going
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on and therefore from the computer science perspective, you hope that a Turing machine
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can be perfectly, can achieve general intelligence.
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Well, you have this wonderful thing about Turing and Gertl and Church and Cary and various
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people, particularly Turing, and I guess Post was the other one, these people who develop
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the idea of what a computation is.
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And there were different ideas of what a computer developed differently.
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I mean, Church is where they're doing it was very different from Turing's, but then they
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were shown to be equivalent.
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And so the view emerged that what we mean by a computation is a very clear concept.
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And one of the wonderful things that Turing did was to show that you could have what we
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call a universal Turing machine.
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You just have to have a certain finite device.
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Okay, it has to have an unlimited storage space, which is accessible to it, but the
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actual computation, if you like, is performed by this one universal device.
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And so the view comes away, well, you have this universal Turing machine and maybe the
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brain is something like that, a universal Turing machine, and it's got maybe not an
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unlimited storage, but a huge storage accessible to it.
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And this model is one, which is what's used in ordinary computation.
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It's a very powerful model.
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And the universalness of computation is very useful.
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You can have some problem and you may not see immediately how to put it onto a computer,
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but if it is something of that nature, then there are all sorts of subprograms and subroutines
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and all the...
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I mean, I learned a little bit of computing when I was a student, but not very much.
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But it was enough to get the general ideas.
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And there's something really pleasant about a formal system like that, where you can start
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discussing about what's provable, what's not, these kinds of things.
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And you've got a notion, which is an absolute notion, this notion of computability and address
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when mathematical problems are computably solvable and what chance.
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And it's a very beautiful area of mathematics and it's a very powerful area of mathematics
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and it underlies the whole principles of computing machines that we have today.
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Could you say what is Gato's incompleteness theorem and how does it...
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He also says it's heartbreaking to you and how does it interfere with this notion of
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computation and consciousness?
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Sure.
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Well, the ideas, basically, ideas which I formulated in my first year as a graduate student in
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Cambridge.
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I did my undergraduate work in mathematics in London and I had a colleague, Ian Percival.
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We used to discuss things like computational and logical systems quite a lot.
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I'd heard about Gerdl's theorem and I was a bit worried by the idea that it seemed
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to say there were things in mathematics that you could never prove.
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And so when I went to Cambridge as a graduate student, I went to various courses.
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You see, I was doing pure mathematics.
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I was doing algebraic geometry of a sort, a little bit different from all my supervisors
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and people.
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But it was algebraic geometry.
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And I was interested.
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I got particularly interested in three lecture courses that were nothing to do with what
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I was supposed to be doing.
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One was a course by Herman Bondi on Einstein's general theory of relativity, which was a
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beautiful course.
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He was an amazing lecturer, brought these things alive, absolutely.
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And now there was a course on quantum mechanics, given by the great physicist Paul Dirac.
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It was a beautiful course in a completely different way.
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He was very kind of organized and never got excited about anything, seemingly.
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But it was extremely well put together and I found that amazing too.
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The third course that was nothing to do with what I should be doing was a course on mathematical
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logic.
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And I got excited, as I say, my discussions with Ian Percival.
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There's an incompleteness theorem already deeply within mathematical logic.
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Were you introduced to it?
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I was introduced to it in detail by the course by Steen.
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And it was two things he described, which were very fundamental to my understanding.
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One was Turing machines and the whole idea of computability and all that.
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So that was all very much part of the course.
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The other one was the girdle theorem, and it wasn't what I was afraid it was to tell
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you there were things in mathematics you couldn't prove.
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It was basically, and he phrased it in a way which often people didn't.
link |
00:19:53.200
And if you read Douglass Hofstadter's book, he doesn't, you see.
link |
00:19:56.520
But Steen made it very clear and also in a sort of public lecture that he gave to a mathematical,
link |
00:20:02.840
I think it may be the Adams Society, one of the mathematical undergraduate societies,
link |
00:20:07.200
and he made this point again very clearly, that if you've got a formal system of proof.
link |
00:20:11.920
So suppose what you mean by proof is something which you could check with a computer.
link |
00:20:19.280
So to say whether you've got it right or not, you've got a lot of steps.
link |
00:20:22.520
Have you carried this computational procedure following the proof, steps of the proof correctly,
link |
00:20:30.680
that can be checked by an algorithm, by a computer.
link |
00:20:35.560
So that's the key thing.
link |
00:20:38.880
Now what, you have to, now you see, is this any good?
link |
00:20:44.520
If you've got an algorithmic system which claims to say, yes, this is right, no, you've
link |
00:20:50.320
proved it correctly, this is true, if you've proved it, if you made a mistake, it doesn't
link |
00:20:55.080
say it's true or false, but if you've done it right, then the conclusion you've come
link |
00:20:59.920
to is correct.
link |
00:21:01.320
Now you say, why do you believe it's correct?
link |
00:21:03.960
Because you've looked at the rules and you said, well, okay, that one's all right, yeah,
link |
00:21:06.920
that one's all right, what about, oh, yeah, I see, I see why it's all right, okay.
link |
00:21:10.640
You go through all the rules, you say, yes, following those rules, if it says yes, it's
link |
00:21:15.080
true, it is true.
link |
00:21:16.880
So you've got to make sure that these rules are ones that you trust.
link |
00:21:22.080
If you follow the rules and it says it's a proof, is the result actually true?
link |
00:21:27.680
And that your belief that it's true depends upon looking at the rules and understanding
link |
00:21:32.760
them.
link |
00:21:34.520
Now what Goethe shows is that if you have such a system, then you can construct a statement
link |
00:21:41.360
of the very kind that it's supposed to look at, a mathematical statement, and you can
link |
00:21:46.080
see by the way it's constructed and what it means that it's true, but not provable
link |
00:21:55.280
by the rules that you've been given, and it depends on your trust in the rules.
link |
00:22:00.960
Do you believe that the rules only give you truth?
link |
00:22:03.400
If you believe the rules only give you truth, then you believe this other statement is also
link |
00:22:07.600
true.
link |
00:22:08.600
I found this absolutely mind blowing.
link |
00:22:10.880
When I saw this, it blew my mind.
link |
00:22:13.200
I thought, my God, you can see that this statement is true, it's as good as any proof, because
link |
00:22:20.000
it only depends on your belief in the reliability of the proof procedure, that's all it is,
link |
00:22:26.720
and understanding that the coding is done correctly, and it enables you to transcend
link |
00:22:32.040
that system.
link |
00:22:33.920
So whatever system you have, as long as you can understand what it's doing and why you
link |
00:22:39.480
believe it only gives you truth, then you can see beyond that system.
link |
00:22:44.080
Now how do you see beyond it?
link |
00:22:46.400
What is it that enables you to transcend that system?
link |
00:22:51.000
Well, it's your understanding of what the system is actually saying, and what the statement
link |
00:22:56.680
that you've constructed is actually saying.
link |
00:22:59.520
So it's this quality of understanding, whatever it is, which is not governed by rules.
link |
00:23:05.640
It's not a computational procedure.
link |
00:23:07.480
So this idea of understanding is not going to be within the rules of the formal system.
link |
00:23:13.280
Yes, you're only using those rules anyway, because you have understood them to be rules
link |
00:23:18.240
which only give you truth.
link |
00:23:19.760
There'd be no point in it otherwise.
link |
00:23:22.000
I mean, people say, well, okay, this is one set of rules as good as any other.
link |
00:23:28.080
Well, it's not true.
link |
00:23:29.080
You have to understand what the rules mean, and why does that understanding of the mean
link |
00:23:33.600
give you something beyond the rules themselves?
link |
00:23:36.920
That's what it was.
link |
00:23:37.920
That's what blew my mind.
link |
00:23:38.920
It's somehow understanding why the rules give you truth enables you to transcend the
link |
00:23:45.120
rules.
link |
00:23:46.120
So that's where, I mean, even at that time, that's already where the thought entered your
link |
00:23:49.840
mind that the idea of understanding, or we can start calling it things like intelligence
link |
00:23:56.800
or even consciousness is outside the rules.
link |
00:23:59.840
Yes.
link |
00:24:00.840
I've always concentrated on understanding.
link |
00:24:03.440
People say, people are talking about creativity, that's something a machine can't do as creative.
link |
00:24:08.960
Well, I don't know what is creativity, and I don't know.
link |
00:24:12.600
Somebody can put some funny things on a piece of paper and say, that's creative, and you
link |
00:24:15.840
could make a machine do that.
link |
00:24:16.840
Is it really creative?
link |
00:24:17.840
I don't know.
link |
00:24:18.840
You say, I worry about that one.
link |
00:24:20.560
I sort of agree with it in a sense, but it's so hard to do anything with that statement.
link |
00:24:25.600
But understanding, yes, you can.
link |
00:24:27.880
You can go see that understanding whatever it is, and it's very hard to put your finger
link |
00:24:33.840
on it.
link |
00:24:34.840
That's absolutely true.
link |
00:24:35.920
Can you try to define or maybe dance around a definition of understanding?
link |
00:24:42.080
There's some degree, but I often wondered about this, but there is something there which
link |
00:24:47.160
is very slippery.
link |
00:24:50.160
It's something like standing back, and it's also got to be something which was of value
link |
00:24:56.800
to our remote ancestors, because sometimes there's a cartoon, which I drew sometimes
link |
00:25:03.080
showing you how all these, in the foreground you see this mathematician just doing some
link |
00:25:07.880
mathematical theorem.
link |
00:25:08.880
There's a little bit of a joke in that theorem, but let's not go into that.
link |
00:25:12.400
He's trying to prove some theorem, and he's about to be eaten by a saber toothed tiger
link |
00:25:17.640
who's hiding in the undergrowth, you see.
link |
00:25:21.360
And in the distance, you see his cousins building growing crops, building shelters, domesticating
link |
00:25:29.800
animals.
link |
00:25:30.800
And in the slight foreground, you see they've built a mammoth trap, and this poor old mammoth
link |
00:25:34.200
is falling into a pit.
link |
00:25:36.320
You see, and all these people around them are about to grab him, you see.
link |
00:25:40.200
And well, you see, those are the ones who, the quality of understanding, which goes with
link |
00:25:46.520
all the, it's not just the mathematician doing his mathematics.
link |
00:25:50.920
This understanding quality is something else, which has been a tremendous advantage to us,
link |
00:25:58.280
not just to us.
link |
00:25:59.280
See, I don't think consciousness is limited to humans.
link |
00:26:03.240
Yeah, that's the interesting question, at which point, if it is indeed connected to
link |
00:26:07.480
the evolutionary process, at which point did we pick up this?
link |
00:26:11.160
A very hard question.
link |
00:26:13.600
It's certainly, I don't think it's primates, you see these pictures of African hunting
link |
00:26:19.880
dogs and how they can plan amongst themselves how to catch the antelopes.
link |
00:26:25.880
Some of these David Attenborough films, I think it's probably one of them.
link |
00:26:29.280
And you can see the hunting dogs, and they divide themselves into two groups, and they
link |
00:26:34.480
go in two routes, two different routes.
link |
00:26:37.000
One of them goes and they sort of hide next to the river.
link |
00:26:40.840
And the other group goes around and they start yelping at these, they don't bark, I guess
link |
00:26:46.680
whatever noise hunting dogs do, the antelopes.
link |
00:26:49.960
And they sort of round them up and they chase them in the direction of the river.
link |
00:26:54.920
And they're the other ones just waiting for them just to get, because when they get to
link |
00:26:58.600
the river, it slows them down.
link |
00:27:00.400
And so they pounce on them.
link |
00:27:02.160
So they've obviously planned this all out, somehow, I have no idea how.
link |
00:27:07.920
And there is some element of conscious planning, as far as I can see.
link |
00:27:12.240
I don't think it's just some kind of, so much of AI these days is done, they call bottom
link |
00:27:19.760
up systems.
link |
00:27:20.760
Is it where you have neural networks and you give them a zillion different things to look
link |
00:27:27.000
at, and then they sort of can choose one thing over another, just because it's seen so many
link |
00:27:34.720
examples and picks up on little signals, which one may not even be conscious of.
link |
00:27:41.640
And that doesn't feel like understanding.
link |
00:27:43.240
There's no understanding in that whatsoever.
link |
00:27:45.440
Well, you're being a little bit human centric.
link |
00:27:48.520
So I think I would expect...
link |
00:27:50.680
Well, I'm talking about...
link |
00:27:51.680
See, I'm not with the dogs, am I?
link |
00:27:52.680
No, you're not.
link |
00:27:53.680
Sorry, not human centric, but I misspoke, biology centric.
link |
00:27:59.400
Is it possible that consciousness would just look slightly different?
link |
00:28:02.560
Well, I'm not saying it's biological, because we don't know.
link |
00:28:05.720
Right.
link |
00:28:06.720
I think other examples of the elephants is a wonderful example, too, where this was,
link |
00:28:11.840
I think this was at number one, where the elephants have to go from the long, the troop
link |
00:28:17.520
of them have to go long distances, and the leader of a troop is a female.
link |
00:28:21.640
They all are, apparently.
link |
00:28:23.760
And this female, she had to go all the way from one part of the country to another.
link |
00:28:30.200
And at a certain point, she made a detour, and they went off in this big detour.
link |
00:28:35.080
All the troop came with her.
link |
00:28:37.280
And this is where her sister had died.
link |
00:28:39.920
And there were her bones lying around, and they go and pick up the bones, and they hand
link |
00:28:43.280
it around, and they caress the bones, and then they put them back, and they will go
link |
00:28:47.280
back again.
link |
00:28:48.280
What in the hell are they doing?
link |
00:28:51.440
That's so interesting.
link |
00:28:52.440
I mean, there's something going on.
link |
00:28:54.640
There's no clear connection with natural selection.
link |
00:28:59.600
There's just some deep feeling going on there.
link |
00:29:03.160
We have to do with their conscious experience.
link |
00:29:07.320
And I think it's something that, overall, is advantageous, unnatural selection, but
link |
00:29:15.160
not directly to do with natural selection.
link |
00:29:18.680
I like that there's something going on there.
link |
00:29:22.600
Like I told you, I'm Russian, so I tend to romanticize all things of this nature, that
link |
00:29:28.920
it's not merely cold, hard computation.
link |
00:29:32.560
Perhaps I could just slightly answer your question.
link |
00:29:35.920
You were asking me, what is it?
link |
00:29:38.720
There's something about sort of standing back and thinking about your own thought processes.
link |
00:29:43.960
I mean, there is something like that in the girdle thing, because if you're not following
link |
00:29:49.120
the rules, you're standing back and thinking about the rules.
link |
00:29:53.640
And so there is something that you might say, you think about you're doing something, and
link |
00:29:58.280
you think, what the hell am I doing?
link |
00:30:00.240
And you sort of stand back and think about what it is that's making you think in such
link |
00:30:04.360
a way.
link |
00:30:05.360
Just take a step back outside the game you've been playing.
link |
00:30:08.600
Yeah.
link |
00:30:09.600
You back up, and you think about, you're just not playing the game anymore.
link |
00:30:12.640
You're thinking about what the hell you're doing in playing this game.
link |
00:30:16.160
And that's somehow, it's not a very precise description, but somehow it feels very true
link |
00:30:22.120
that that's somehow understanding, this kind of reflection.
link |
00:30:25.880
A reflection, yes.
link |
00:30:27.360
Yeah.
link |
00:30:28.360
Yeah.
link |
00:30:29.360
It's a bit hard to put your finger on, but there is something there which I think maybe
link |
00:30:32.840
could be unearthed at some point, and see this is really what's going on.
link |
00:30:36.960
Why conscious beings have this advantage?
link |
00:30:40.280
What it is that gives them advantage, and I think it goes way back.
link |
00:30:44.160
I don't think, we're talking about the hunting dogs and the elephants, that's pretty clear
link |
00:30:49.240
that octopuses have the same sort of quality, and we call it consciousness.
link |
00:30:54.400
Yeah, I think so.
link |
00:30:55.400
I've seen enough examples of the way that they behave, and the evolution route is completely
link |
00:31:01.760
different.
link |
00:31:02.760
Does it go way back to some common ancestor, or did it come separately?
link |
00:31:07.640
My hope is it's something simple, but the hard question, if there's a hardware prerequisite,
link |
00:31:13.680
we have to develop some kind of hardware mechanisms in our computers.
link |
00:31:19.080
Basically, as you suggest, and we'll get to in a second, we kind of have to throw away
link |
00:31:23.760
the computer as we know it today, the deterministic machines we know today to try to create it.
link |
00:31:30.360
My hope, of course, is not.
link |
00:31:32.880
Well, I should go really back to the story, which in a sense, I haven't finished, because
link |
00:31:40.080
I went to these three courses, you see, when I was a graduate student, and so I started
link |
00:31:44.920
to think, well, I'm really, I'm a pretty, what you might call a materialist in the sense
link |
00:31:50.080
of thinking that there's no kind of mystical or something or other, which comes in from
link |
00:31:55.080
who knows where.
link |
00:31:56.080
You still that?
link |
00:31:57.080
Yeah, you still throughout your life been a materialist?
link |
00:31:58.520
I don't like the word materialist because it suggests we know what material is, and
link |
00:32:03.000
that is a bad word because there's no mystical.
link |
00:32:07.760
It's not some mystical something which is not treatable by science.
link |
00:32:11.840
That's so beautifully put.
link |
00:32:12.840
Just to pause on that for a second.
link |
00:32:14.440
You're a materialist, but you acknowledge that we don't really know what the material
link |
00:32:18.600
is.
link |
00:32:19.600
That's right.
link |
00:32:20.600
I mean, I like to call myself a scientist, I suppose, but it means that, yes, what you
link |
00:32:28.080
see, the question goes on here.
link |
00:32:29.800
So I began thinking, okay, if consciousness or understanding is something which is not
link |
00:32:36.440
a computational process, what can it be?
link |
00:32:40.160
And I knew enough from my undergraduate work, I knew about Newtonian mechanics, and I knew
link |
00:32:46.480
how basically you could put it on a computer.
link |
00:32:50.240
There is a fundamental issue which is this important or not that computation depends
link |
00:32:56.200
upon discrete things, so you're using discrete elements, whereas the physical laws depend
link |
00:33:04.440
on the continuum.
link |
00:33:06.640
Is this something to do with it?
link |
00:33:09.760
Is it the fact that we use the continuum in our physics?
link |
00:33:13.000
And if we model our physical system, we use discrete systems like ordinary computers.
link |
00:33:19.040
I came to the view that that's probably not it.
link |
00:33:21.920
I might have to retract on that someday, but the view was no, you can get close enough.
link |
00:33:28.440
It's not altogether clear, I have to say, but you can get close enough.
link |
00:33:33.360
And I went to this course by Bondi on general relativity, and I thought, well, you can put
link |
00:33:38.160
that on a computer.
link |
00:33:39.160
Of course, that was a long time before people, and I've sort of grown up with this, how people
link |
00:33:44.400
have done better and better calculations, and they could work out black holes, and they
link |
00:33:48.400
can then work out how black holes can interact with each other, spar around, and what kind
link |
00:33:53.080
of gravitational waves can out, and there's a very impressive piece of computational work,
link |
00:33:58.680
how you can actually work out the shapes of those signals.
link |
00:34:02.040
Now we have LIGO seeing these signals, and they say, yeah, those black holes spiral into
link |
00:34:06.120
each other.
link |
00:34:07.520
This is just a vindication of the power of computation in describing Einstein's general
link |
00:34:14.880
relativity.
link |
00:34:15.880
So in that case, we can get close, but with computation, we can get close to understanding
link |
00:34:22.760
the physics.
link |
00:34:23.760
You can get very, very close.
link |
00:34:24.760
Now, is that close enough, you see?
link |
00:34:27.040
And then I went to this course by Dirac.
link |
00:34:29.000
Now, you see, I think it was the very first lecture that he gave, and he was talking about
link |
00:34:35.320
the superposition principle, and he said, if you have a particle, you usually think of
link |
00:34:40.520
particle can be over here or over there, but in quantum mechanics, it can be over here
link |
00:34:45.160
and over there at the same time.
link |
00:34:48.160
And you have these states which involve a superposition, in some sense, of different
link |
00:34:54.240
locations for that particle.
link |
00:34:56.760
And then he got out his piece of chalk, and some people say he broke it in two as a kind
link |
00:35:00.320
of illustration of how the piece of chalk might be over here and over there at the same
link |
00:35:05.120
time.
link |
00:35:06.880
And he was talking about this, and my mind wondered, I don't remember what he said.
link |
00:35:13.400
All I can remember, he's just moved on to the next topic, and something about energy
link |
00:35:17.760
he'd mentioned, which I had no idea what had to do with anything.
link |
00:35:21.160
And so I'd been struck with this and worried about it ever since.
link |
00:35:25.320
It's probably just as well, I didn't hear his explanation, because it was probably one
link |
00:35:28.720
of these things to calm me down and not worry about it anymore, whereas in my case, I've
link |
00:35:33.720
worried about it ever since.
link |
00:35:35.960
So I thought, maybe that's the catch.
link |
00:35:38.520
There is something in quantum mechanics, where these superpositions become one or the other.
link |
00:35:45.280
And that's not part of quantum mechanics, there's something missing in the theory.
link |
00:35:50.040
The theory is incomplete, it's not just incomplete, it's in a certain sense not quite right.
link |
00:35:55.280
Because if you follow the equation, the basic equation of quantum mechanics, that's the
link |
00:35:59.480
Schrodinger equation, you could put that on a computer too, there are lots of difficulties
link |
00:36:03.640
about how many parameters you have to put in and so on, that can be very tricky.
link |
00:36:07.560
But nevertheless, it is a computational process, modulo this question about the continuum
link |
00:36:13.480
as before, but it's not clear that makes any difference.
link |
00:36:17.000
So our theories of quantum mechanics may be missing the same element that the universal
link |
00:36:23.040
term machine is missing about consciousness.
link |
00:36:25.480
Yes, yes.
link |
00:36:26.480
Yeah, this is the view I held, is that you need a theory and that that, what people call
link |
00:36:32.360
the reduction of the state or the collapse of the wave function, which you have to have,
link |
00:36:36.800
otherwise quantum mechanics doesn't relate to the world we see.
link |
00:36:39.960
To make it relate to the world we see, you've got to break the Schrodinger equation.
link |
00:36:45.400
Schrodinger himself was absolutely appalled by this idea, his own equation.
link |
00:36:50.560
I mean, that's why he introduced this famous Schrodinger's cat as a thought experiment.
link |
00:36:56.200
He's really saying, look, this is where my equation leads you into it.
link |
00:36:59.640
There's something wrong, something we haven't understood, which is basically fundamental.
link |
00:37:05.640
And so I was trying to put all these things together and said, well, it's got to be the
link |
00:37:09.120
noncomputability comes in there.
link |
00:37:12.200
And I also can't remember when I thought this, but it's when gravity is involved in quantum
link |
00:37:16.920
mechanics.
link |
00:37:17.920
It's the combination of those two.
link |
00:37:19.880
And that's that point when you have good reasons to believe, this came much later, that I have
link |
00:37:28.000
good reason to believe that the principles of general relativity and those of quantum
link |
00:37:33.680
mechanics.
link |
00:37:34.680
Particularly, it's the basic principle of equivalence, which goes back to Galileo.
link |
00:37:41.440
If you fall freely, you eliminate the gravitational field.
link |
00:37:46.480
So you imagine Galileo dropping his big rock and his little rocks from the Leaning Tower,
link |
00:37:52.600
whether he actually ever did that or not, that's pretty irrelevant.
link |
00:37:55.840
And as the rocks fall to the ground, you have a little insect sitting on one of them looking
link |
00:37:59.960
at the other one.
link |
00:38:01.520
And it seems to think, oh, there's no gravity here.
link |
00:38:03.920
Of course, it hits the ground and then you realize something's different going on.
link |
00:38:07.960
But when it's in free fall, the gravity has been eliminated.
link |
00:38:11.920
Galileo understood that very beautifully.
link |
00:38:14.400
He gives these wonderful examples of fireworks.
link |
00:38:18.640
And you see the fireworks and explode, and you see the sphere of sparkling fireworks,
link |
00:38:23.440
and it remains a sphere as it falls down, as though there were no gravity.
link |
00:38:29.320
So he understood that principle.
link |
00:38:31.360
But he couldn't make a theory out of it.
link |
00:38:33.520
Einstein came along, used exactly the same principle, and that's the basis of Einstein's
link |
00:38:38.920
general theory of relativity.
link |
00:38:41.440
Now there is a conflict.
link |
00:38:43.640
This is something I did much, much later.
link |
00:38:45.320
So this wasn't those days, much, much later.
link |
00:38:49.000
You can see there is a basic conflict between the principle of superposition, the thing
link |
00:38:54.680
that Dirac was talking about, and the principle of general covariant.
link |
00:38:58.840
Well, principle of equivalence, gravitational field is equivalent to an acceleration.
link |
00:39:03.760
Can you pause for a second?
link |
00:39:04.960
What is the principle of equivalence?
link |
00:39:07.000
It's this Galileo principle that we can eliminate, at least locally.
link |
00:39:11.640
You have to be in a small neighborhood because you see if you have people dropping rocks
link |
00:39:16.320
all around the world somewhere, you can't get rid of it all at once.
link |
00:39:20.000
But in the local neighborhood, you can eliminate the gravitational field by falling freely
link |
00:39:25.440
with it.
link |
00:39:26.440
And we now see that with astronauts and they don't, you know, the Earth is right there.
link |
00:39:30.680
You can see the great globe of the Earth right beneath them, but they don't care about it.
link |
00:39:35.400
As far as they're concerned, there's no gravity.
link |
00:39:39.120
They fall freely in the gravitational field, and that gets rid of the gravitational field.
link |
00:39:45.120
And that's the principle of equivalence.
link |
00:39:46.760
So what's the contradiction?
link |
00:39:49.000
What's the tension with superposition and equivalence?
link |
00:39:51.120
Well, that's technical.
link |
00:39:53.120
So it's just a backtrack for a second just to see if we can weave a thread through it
link |
00:39:57.160
all.
link |
00:39:58.160
Yes.
link |
00:39:59.160
So we started to think about consciousness as potentially needing some of the same, not
link |
00:40:06.880
mystical, but some of the same magic.
link |
00:40:08.720
You see, it is a complicated story.
link |
00:40:10.640
So, you know, people think, oh, I'm drifting away from the point or something.
link |
00:40:14.240
But I think it is a complicated story.
link |
00:40:16.760
So what I'm trying to say, I mean, I try to put it in a nutshell, but it's not so easy.
link |
00:40:20.600
I'm trying to say that whatever consciousness is, it's not a computation.
link |
00:40:26.560
Yes.
link |
00:40:27.560
Or it's not a physical process which can be described by computation.
link |
00:40:33.480
But it nevertheless could be.
link |
00:40:34.920
So one of the interesting models that you've proposed is the orchestrated objective reduction.
link |
00:40:41.680
Yes.
link |
00:40:42.680
But you see, that's going from there, you see.
link |
00:40:44.720
So I say, I have no idea.
link |
00:40:46.800
So I wrote this book through my scientific career, I thought, you know, when I'm retired,
link |
00:40:52.080
I'll have enough time to write a sort of a popular book which I will explain my ideas
link |
00:40:59.440
and puzzles, what I like, beautiful things about physics and mathematics, and this puzzle
link |
00:41:05.200
about computability and consciousness and so on.
link |
00:41:09.960
And in the process of writing this book, well, I thought I'd do it when I was retired.
link |
00:41:14.360
I didn't actually.
link |
00:41:15.360
I didn't wait that long because there was a radio discussion between Edward Fredkin
link |
00:41:21.960
and Marvin Minsky.
link |
00:41:24.520
And they were talking about what computers could do.
link |
00:41:28.480
And they were entering a big room.
link |
00:41:30.640
They imagined entering this big room.
link |
00:41:32.040
At the other end of the room, two computers were talking to each other.
link |
00:41:37.040
And as you walk up to the computers, they will have communicated to each other more ideas,
link |
00:41:43.840
concepts, things than the entire human race had ever commuted at that level.
link |
00:41:49.200
So I thought, well, I know where you're coming from, but I just don't believe you.
link |
00:41:53.760
There's something missing.
link |
00:41:57.200
So I thought, well, I should write my book.
link |
00:42:00.560
And so I did.
link |
00:42:01.720
It was roughly the same time Stephen Hawking was writing his brief history of time.
link |
00:42:08.640
The 80s at some point.
link |
00:42:11.280
The book you're talking about is The Emperor's New Mind.
link |
00:42:13.280
That's right.
link |
00:42:14.280
And both are incredible books, the brief history of time, and The Emperor's New Mind.
link |
00:42:18.160
Yes.
link |
00:42:19.160
It was quite interesting because he told me he'd got Carl Sagan, I think, to write it
link |
00:42:23.960
forward.
link |
00:42:24.960
It's a good guess.
link |
00:42:25.960
To the book, you see.
link |
00:42:26.960
So I thought, gosh, what am I going to do?
link |
00:42:27.960
I'm not going to get anywhere unless I get somebody.
link |
00:42:30.960
So I said, well, I know Martin Gardner, so I wonder if he'd do it.
link |
00:42:34.480
So he did.
link |
00:42:35.480
And he did a very nice forward.
link |
00:42:36.760
So that's an incredible book.
link |
00:42:38.280
And some of the same people you mentioned, Ed Franken, which I guess of expert systems
link |
00:42:44.200
fame and Minsky, of course, people know in the AI world, but they represent the artificial
link |
00:42:48.240
intelligence world.
link |
00:42:49.240
Absolutely.
link |
00:42:50.240
That's right.
link |
00:42:51.240
That do hope and dream that AI's intelligence is.
link |
00:42:53.240
That's right.
link |
00:42:54.240
Well, you see, it was my thinking.
link |
00:42:55.240
Well, you know, I see where they're coming from, and from that perspective, yeah, you're
link |
00:42:59.200
right.
link |
00:43:00.200
But that's not my perspective.
link |
00:43:01.760
So I thought I had to say it.
link |
00:43:03.560
And as I was writing my book, you see, I thought, well, I don't really know anything about neurophysiology.
link |
00:43:07.840
What am I doing writing this book?
link |
00:43:09.280
So I started reading up about neurophysiology, and I read up nothing.
link |
00:43:13.080
And I try to find out how it is that nerve signals could possibly preserve quantum coherence.
link |
00:43:18.480
And all I read is that the electrical signals which go along the nerves create effects through
link |
00:43:24.800
the brain.
link |
00:43:25.800
There's no chance you can isolate it so that this is hopeless.
link |
00:43:29.920
So I come to the end of the book, and I more or less give up.
link |
00:43:33.560
I just think of something which I didn't believe in.
link |
00:43:35.880
That's maybe this is a way around it, but no.
link |
00:43:39.560
And then you say, I thought, well, maybe this book will at least stimulate young people
link |
00:43:43.280
to do science or something.
link |
00:43:45.000
And I got all these letters from older, tired people instead.
link |
00:43:48.040
These are the only people who could have time to read my book, except for Stuart Hameroff.
link |
00:43:54.360
Except for Stuart Hameroff.
link |
00:43:56.360
Stuart Hameroff wrote to me, and he said, I think you're missing something.
link |
00:44:01.200
You don't know about microtubules, do you?
link |
00:44:03.240
He didn't put it quite like that, but that was more or less it.
link |
00:44:06.040
And he said, this is what you really need to consider.
link |
00:44:08.960
So I thought, my God, yes, that's a much more promising structure.
link |
00:44:13.080
So I mean, fundamentally, you were searching for the source of a noncomputable source of
link |
00:44:21.320
consciousness within the human brain in the biology.
link |
00:44:25.160
And so if I may ask, what are microtubules?
link |
00:44:29.920
Well, you see, I was ignorant and what I'd read, I never came across them in the books
link |
00:44:36.360
I looked at.
link |
00:44:37.360
Perhaps I only read rather superficially, which is true.
link |
00:44:41.000
But I didn't know about microtubules.
link |
00:44:43.240
Stuart, I think one of the things he was impressed him about them is that when you see pictures
link |
00:44:47.920
of mitosis, that's a cell dividing, and you see all the chromosomes, and the chromosomes
link |
00:44:54.240
get, or get lined up, and then they get pulled apart.
link |
00:44:58.120
And so that as the cell divides, the half the chromosomes go, you know, how they divide
link |
00:45:02.960
into the two parts, and they go two different ways.
link |
00:45:07.560
And what is it that's pulling them apart?
link |
00:45:09.280
Well, those are these little things called microtubules.
link |
00:45:13.040
And so he starts to get interested in them.
link |
00:45:15.800
And he formed the view, well, he was at his day job or night job, or whatever you call
link |
00:45:20.880
it, is to put people to sleep, except he doesn't like calling to sleep because it's different.
link |
00:45:26.080
General anesthetics in a reversible way.
link |
00:45:29.400
So you want to make sure that they don't experience the pain that would otherwise be something
link |
00:45:35.120
that they feel, and consciousness is turned off for a while, and it can be turned back
link |
00:45:41.400
on again.
link |
00:45:42.400
So it's crucial that you can turn it off and turn it on.
link |
00:45:45.320
And what do you do when you're doing that?
link |
00:45:47.560
What do general anesthetic gases do?
link |
00:45:50.720
And see, he formed the view that it's the microtubules that they affect.
link |
00:45:57.240
And the details of why he formed that view is not, or they're clear to me, but there's
link |
00:46:03.040
an interesting story he keeps talking about.
link |
00:46:05.800
But I found this very exciting because I thought these structures, these little tubes which
link |
00:46:13.800
inhabit pretty well all cells, it's not just neurons, apart from red blood cells, they
link |
00:46:20.680
inhabit pretty well all the other cells in the body.
link |
00:46:24.080
But they're not all the same kind.
link |
00:46:25.440
You get different kinds of microtubules.
link |
00:46:28.240
And the ones that excited me the most, this may still not be totally clear, but the ones
link |
00:46:35.000
that excited me most were the ones, the only ones that I knew about at the time because
link |
00:46:39.480
they were very, very symmetrical structures.
link |
00:46:44.320
And I had reason to believe that these very symmetrical structures would be much better
link |
00:46:49.280
at preserving a quantum state, quantum coherence, preserving the thing without, you just need
link |
00:46:56.200
to preserve certain degrees of freedom without them leaking into the environment.
link |
00:47:01.240
Once they leak into the environment, you're lost.
link |
00:47:03.000
So you've got to preserve these quantum states at a level which the state reduction process
link |
00:47:11.240
comes in, and that's where I think the non computability comes in, and it's the measurement
link |
00:47:18.360
process in quantum mechanics, what's going on.
link |
00:47:20.960
So something about the measurement process and what's going on, something about the structure
link |
00:47:25.360
of the microtubules, your intuition says maybe there's something here, maybe this kind
link |
00:47:30.560
of structure allows for the mystery of the quantum mechanics.
link |
00:47:35.600
There was a much better chance, yes, it just struck me that partly it was the symmetry
link |
00:47:40.760
because there is a feature of symmetry, you can preserve quantum coherence much better
link |
00:47:46.720
with symmetrical structures.
link |
00:47:48.480
There's a good reason for that.
link |
00:47:50.560
And that impressed me a lot.
link |
00:47:52.560
I didn't know the difference between the A lattice and B lattice at that time, which
link |
00:47:56.000
could be important.
link |
00:47:57.000
No, that could be, which isn't talked about much.
link |
00:48:00.960
But that's in some sense details, we're going to take a step back just to say in case people
link |
00:48:04.840
are not familiar.
link |
00:48:05.840
So this was called the orchestrated objective reduction idea or ORC ORR, which is a by
link |
00:48:16.680
biological philosophy of mind that postulates that consciousness originates at the quantum
link |
00:48:21.280
level inside neurons.
link |
00:48:22.360
So that has to do with your search for where, where is it coming from?
link |
00:48:26.720
So that's counter to the notion that consciousness may arise from the computation performed by
link |
00:48:31.600
the synapses.
link |
00:48:32.600
Yes, the key point, sometimes people say it's because it's quantum mechanical, it's not
link |
00:48:41.560
just that.
link |
00:48:42.560
You see, it's more outrageous than that, you see, this is one reason I think we're so far
link |
00:48:46.880
off from it, because we don't even know the physics right.
link |
00:48:51.080
You see, it's not just quantum mechanics, people say, oh, you know, quantum systems and biological
link |
00:48:56.680
structures.
link |
00:48:57.680
No, will you starting to see that some basic biological systems does depend on quantum?
link |
00:49:04.680
I mean, look, in the first place, all of chemistry is quantum mechanics, people got used to that
link |
00:49:10.800
so they don't count that.
link |
00:49:13.160
So he said, let's not count quantum chemistry, we sort of got the hang of that, they think.
link |
00:49:19.280
But you have quantum effects, which are not just chemical, in photosynthesis.
link |
00:49:25.520
And this is one of the striking things in the last several years, that photosynthesis
link |
00:49:30.360
seems to be a basically quantum process, which is not simply chemical, it's using quantum
link |
00:49:38.880
mechanics in a very basic way.
link |
00:49:41.560
So you can start saying, oh, well, with photosynthesis is based on quantum mechanics, why not behavior
link |
00:49:48.560
of neurons and things like that?
link |
00:49:50.440
Maybe there's something which is a bit like photosynthesis in that respect.
link |
00:49:55.120
But what I'm saying is even more outrageous than that, because those things are talking
link |
00:50:00.760
about conventional quantum mechanics.
link |
00:50:03.800
Now my argument says that conventional quantum mechanics, if you're just following the Schrodinger
link |
00:50:08.760
equation, that's still computable, so you've got to go beyond that.
link |
00:50:13.360
So you've got to go to where quantum mechanics goes wrong, in a certain sense.
link |
00:50:20.760
You have to be a little bit careful about that, because the way people do quantum mechanics
link |
00:50:25.960
is a sort of mixture of two different processes.
link |
00:50:32.920
One of them is the Schrodinger equation, which is an equation Schrodinger wrote down, and
link |
00:50:38.920
it tells you how the state of a system evolves, and it evolves according to this equation,
link |
00:50:44.880
completely deterministic, but it involves inter ridiculous situations.
link |
00:50:50.440
And this was what Schrodinger was very much pointing out with his cat.
link |
00:50:53.480
He said, you follow my equation, that's Schrodinger's equation, and you could say that you have
link |
00:50:59.920
a cat, which is dead and alive at the same time.
link |
00:51:04.360
That would be the evolution of the Schrodinger equation would lead to a state, which is the
link |
00:51:09.120
cat being dead and alive at the same time.
link |
00:51:12.840
And he's more or less saying, this is an absurdity.
link |
00:51:16.840
People nowadays say, oh, Schrodinger said you can have a cat, which is dead, and that's
link |
00:51:19.720
not that.
link |
00:51:20.720
You see, he was saying, this is an absurdity.
link |
00:51:23.560
There's something missing.
link |
00:51:25.840
And that the reduction of the state, or the collapse of the wave function, or whatever
link |
00:51:30.360
it is, is something which has to be understood.
link |
00:51:34.880
It's not following the Schrodinger equation.
link |
00:51:37.960
It's not the way we conventionally do quantum mechanics.
link |
00:51:42.000
There's something more than that.
link |
00:51:44.840
And it's easy to quote authority here, because Einstein, at least three of the greatest physicists
link |
00:51:52.440
of 20th century, who were very fundamental in developing quantum mechanics, Einstein,
link |
00:51:59.360
one of them, Schrodinger, another, Dirac, another.
link |
00:52:03.680
You have to look carefully at Dirac's writing, because he didn't tend to say this out loud
link |
00:52:08.720
very much, because he was very cautious about what he said.
link |
00:52:11.400
You find the right place, and you see, he says quantum mechanics is a provisional theory.
link |
00:52:18.160
We need something which explains the collapse of the wave function.
link |
00:52:23.600
We need to go beyond the theory we have now.
link |
00:52:27.960
I happen to be one of the kinds of people, there are many, there is a whole group of
link |
00:52:31.480
people, they're all considered to be a bit, you know, a bit mavericks, who believe that
link |
00:52:36.240
quantum mechanics needs to be modified.
link |
00:52:39.080
There's a small minority of those people, which are already a minority, who think that
link |
00:52:44.760
the way in which it's modified has to be with gravity.
link |
00:52:48.880
And there is an even smaller minority of those people who think it's a particular way that
link |
00:52:52.760
I think it is, you see.
link |
00:52:55.240
So those are the quantum gravity folks, but what's what?
link |
00:52:57.560
You see, quantum gravity is already not this, because when you say quantum gravity, what
link |
00:53:02.760
you really mean is quantum mechanics applied to gravitational theory.
link |
00:53:07.600
So you say, let's take this wonderful formalism of quantum mechanics and make gravity fit
link |
00:53:14.320
into it.
link |
00:53:15.320
So that is what quantum gravity is meant to be.
link |
00:53:18.120
Now I'm saying, you've got to be more even handed, that gravity affects the structure
link |
00:53:23.080
of quantum mechanics too, it's not just you quantize gravity, you've got to gravitize
link |
00:53:27.840
quantum mechanics.
link |
00:53:29.560
And it's a two way thing.
link |
00:53:31.240
But then when do you even get started, so that you're saying that we have to figure
link |
00:53:35.000
out a totally new idea isn't it?
link |
00:53:37.400
Exactly.
link |
00:53:38.400
No, you're stuck, you don't have a theory, that's the trouble.
link |
00:53:42.880
So this is a big problem if you say, okay, well, what's the theory?
link |
00:53:45.960
I don't know.
link |
00:53:46.960
So maybe in the very early days sort of, it is in the very early days, but just making
link |
00:53:51.920
this point.
link |
00:53:52.920
Yes.
link |
00:53:53.920
You see, Stuart Hammerhoff tends to be, oh, Penrose says that it's got to be a reduction
link |
00:53:58.640
of the state and so on.
link |
00:53:59.640
So let's use it.
link |
00:54:00.640
The trouble is Penrose doesn't say that.
link |
00:54:02.160
Penrose says, well, I think that.
link |
00:54:05.560
We have no experiments as yet, which shows that there are experiments which are being
link |
00:54:11.800
thought through and which I'm hoping will be performed.
link |
00:54:15.840
There is an experiment which is being developed by Dirk Baumeester, who is known for a long
link |
00:54:20.960
time, who shares his time between Leiden in the Netherlands and Santa Barbara in the US.
link |
00:54:28.080
And he's been working on an experiment which could perhaps demonstrate that quantum mechanics,
link |
00:54:35.280
as we now understand it, if you don't bring in the gravitational effects, it has to be
link |
00:54:40.920
modified.
link |
00:54:42.960
And then there's also experiments that are underway that kind of look at the microtubule
link |
00:54:49.560
side of things to see if there's, in the biology, you could see something like that.
link |
00:54:53.920
Could you briefly mention it, because that's really sort of one of the only experimental
link |
00:54:58.960
attempts in the very early days of even thinking about caution.
link |
00:55:02.680
I think there's a very serious area here, which is what Stuart Hammerhoff is doing, and
link |
00:55:07.360
I think it's very important.
link |
00:55:09.160
One of the few places that you can really get a bit of a handle on what consciousness
link |
00:55:13.400
is, is what turns it off.
link |
00:55:17.160
And when you're thinking about general anesthetics, it's very specific.
link |
00:55:21.800
These things turn consciousness off.
link |
00:55:24.360
What the hell do they do?
link |
00:55:25.920
Well, Stuart and a number of people who work with him and others happen to believe that
link |
00:55:33.200
the general anesthetics directly affect microtubules.
link |
00:55:36.920
And there is some evidence for this.
link |
00:55:38.640
I don't know how strong it is and how watertight the case is, but I think there is some evidence
link |
00:55:45.360
pointing in that kind of direction.
link |
00:55:49.280
It's not just an ordinary chemical process, there's something quite different about it.
link |
00:55:53.840
And one of the main candidates is that these anesthetic gases do affect directly microtubules.
link |
00:56:02.840
And how strong that evidence is, I wouldn't be in a position to say.
link |
00:56:07.200
And I think there is fairly impressive evidence.
link |
00:56:10.120
And the point is the experiments are being undertaken.
link |
00:56:12.760
Yes.
link |
00:56:13.760
I mean, that is experimental.
link |
00:56:14.760
It's a very clear direction where you can think of experiments which could indicate
link |
00:56:20.760
whether or not it's really microtubules, which the anesthetic gases directly affect.
link |
00:56:26.240
That's really exciting.
link |
00:56:27.440
One of the sad things is, as far as I'm from my outside perspective, is not many people
link |
00:56:32.960
are working on this.
link |
00:56:34.560
So there's a very, like with Stuart, it feels like there's very few people carrying the
link |
00:56:39.400
flag forward on this.
link |
00:56:41.240
I think it's not many in the sense it's a minority, but it's not zero anymore.
link |
00:56:46.160
You see, when Stuart and I were originally taught by us, we were just us and a few of
link |
00:56:51.760
our friends, there weren't many people taking it, but it's grown into one of the main viewpoints.
link |
00:56:59.560
There might be about four or five or six different views that people hold, and it's one of them.
link |
00:57:08.160
It's considered as one of the possible lines of thinking, yes.
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00:57:13.520
You describe physics theories as falling into one of three categories, the superb, the useful
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00:57:18.480
or the tentative.
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00:57:19.480
I like those words.
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00:57:21.760
It's a beautiful categorization.
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00:57:23.680
Do you think we'll ever have a superb theory of intelligence and of consciousness?
link |
00:57:29.840
We might.
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00:57:30.840
We're a long way from it.
link |
00:57:33.680
I don't think we're even in the tentative scale.
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00:57:40.080
You don't think we've even entered the realm of tentative?
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00:57:42.240
Probably not.
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00:57:43.240
I think so.
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00:57:44.240
Yeah, that's right.
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00:57:45.240
When you see this so controversial, we don't have a clear view which is accepted by a majority.
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00:57:53.320
You say, yeah, people, most views are computational in one form or another, they think it's some,
link |
00:57:58.080
but it's not very clear because even the IIT people who think of them as computational,
link |
00:58:06.600
but I've heard them say, no, consciousness is supposed to be not computational.
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00:58:09.840
I say, well, if it's not coming, what in the hell is it?
link |
00:58:12.920
What's going on?
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00:58:14.200
What physical processes are going on which are that?
link |
00:58:19.240
What does it mean for something to be computational then?
link |
00:58:21.800
Well, there has to be a process which is, you see, it's very curious the way the history
link |
00:58:31.720
has developed in quantum mechanics because very early on people thought there was something
link |
00:58:36.480
to do with consciousness, but it was almost the other way around.
link |
00:58:40.040
You see, you have to say the Schrodinger equation says all these different alternatives
link |
00:58:44.360
happen all at once, and then when is it that only one of them happens?
link |
00:58:48.160
Well, one of the views, which was quite commonly held by a few distinguished quantum physicists,
link |
00:58:53.560
is when a conscious being looks at the system or becomes aware of it, and at that point
link |
00:58:59.240
it becomes one or the other.
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00:59:02.000
That's a role where consciousness is somehow actively reducing the state.
link |
00:59:07.120
My view is almost the exact opposite of that.
link |
00:59:09.840
It's the state reduces itself in some way, which some non computational way, which we
link |
00:59:16.200
don't understand, we don't have a proper theory of, and that is the building block of
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00:59:22.480
what consciousness is.
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00:59:24.480
So consciousness is the other way around.
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00:59:26.240
It depends on that choice which nature makes all the time when the state becomes one or
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00:59:32.600
the other rather than the superposition of one and the other.
link |
00:59:36.160
And when that happens, there is what we're saying now an element of proto consciousness
link |
00:59:41.160
takes place.
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00:59:43.320
Proto consciousness is, roughly speaking, the building block out of which actual consciousness
link |
00:59:48.280
is constructed.
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00:59:50.120
So you have these proto conscious elements, which are when the state decides to do one
link |
00:59:55.640
thing or the other, and that's the thing which when organized together, that's the
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01:00:01.800
OR part in ORCOR, but the ORC part, that's the OR part, at least one can see where we're
link |
01:00:08.800
deriving as a theory, you can say it's the quantum choice of going this way or that way.
link |
01:00:14.760
But the ORC part, which is the orchestration of this, is much more mysterious.
link |
01:00:19.640
And how does the brain somehow orchestrate all these individual OR processes into a
link |
01:00:26.880
genuine, genuine conscious experience?
link |
01:00:32.560
And it might be something that's beautifully simple, but we're completely in the dark about.
link |
01:00:37.440
Yeah, I think at the moment, that's the thing, we happily put the word ORC down there to
link |
01:00:43.000
say orchestrated, but that's even more unclear what that really means.
link |
01:00:49.240
Just like the word material orchestrated, who knows, and we've been dancing a little
link |
01:00:55.920
bit between the word intelligence or understanding and consciousness.
link |
01:01:01.000
Do you kind of see those as sitting in the same space of mystery as with this space?
link |
01:01:06.160
You see, I tend to say you have understanding and intelligence and awareness.
link |
01:01:14.240
And somehow, understanding is in the middle of it, you see.
link |
01:01:21.160
I like to say, could you say of an entity that is actually intelligent if it doesn't
link |
01:01:28.560
have the quality of understanding?
link |
01:01:29.760
You see, I'm using terms I don't even know how to define, but who cares, I'm just relating
link |
01:01:35.200
to them.
link |
01:01:36.200
They're somewhat poetic, so if I somehow understand them.
link |
01:01:38.640
Yes.
link |
01:01:39.640
That's right.
link |
01:01:40.640
Exactly.
link |
01:01:41.640
But they're not mathematical in nature.
link |
01:01:42.640
Yes, you see, as a mathematician, I don't know how to define any of them, but at least
link |
01:01:45.680
I can point to the connections.
link |
01:01:47.480
So the idea is intelligence is something which I believe needs understanding, otherwise you
link |
01:01:54.400
wouldn't say it's really intelligence.
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01:01:56.520
And understanding needs awareness, otherwise you wouldn't really say it's understanding.
link |
01:02:01.680
Do you say of an entity that understands something unless it's really aware of it, normal usage?
link |
01:02:08.480
So there's a three sort of awareness, understanding, and intelligence.
link |
01:02:13.880
And I just tend to concentrate on understanding because that's where I can say something.
link |
01:02:19.120
And that's the girdle theorem, things like that.
link |
01:02:22.000
But what does it mean to be perceived the color blue or something?
link |
01:02:26.800
I'm a foggiest.
link |
01:02:27.800
That's a much more difficult question.
link |
01:02:30.320
I mean, is it the same if I see a color blue and you see it?
link |
01:02:34.120
If you're assembling with this condition, what does it call them?
link |
01:02:38.440
Over your sign, like a sound to a color that kind of thing.
link |
01:02:42.320
Yeah, that's right.
link |
01:02:43.320
You get colors and sounds mixed up.
link |
01:02:45.120
And that sort of thing.
link |
01:02:46.120
I mean, an interesting subject, I mean.
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01:02:49.280
But from the physics perspective, from the fundamentals perspective, we don't.
link |
01:02:53.120
I think we're way off having much understanding what's going on there.
link |
01:02:57.960
In your 2010 book, Cycles of Time, you suggest that another universe may have existed before
link |
01:03:04.480
the Big Bang.
link |
01:03:06.280
Can you describe this idea?
link |
01:03:08.920
First of all, what is the Big Bang?
link |
01:03:11.080
Sounds like a funny word.
link |
01:03:13.280
And what may have been there before it?
link |
01:03:17.080
Yes.
link |
01:03:18.080
Just as a matter of terminology, I don't like to call it another universe because when you
link |
01:03:22.080
have another universe, you think of it kind of quite separate from us.
link |
01:03:25.560
But these things, they're not separate.
link |
01:03:28.160
Now, the Big Bang, conventional theory.
link |
01:03:31.560
You see, I was actually brought up in the sense of when I started getting interested
link |
01:03:36.160
in cosmology, there was a thing called the steady state model, which was sort of philosophically
link |
01:03:40.560
very interesting.
link |
01:03:41.560
And there wasn't a Big Bang in that theory, but somehow new material was created all the
link |
01:03:46.000
time in the form of hydrogen and the universe kept on expanding and expanding and expanding
link |
01:03:50.400
and there was room for more hydrogen.
link |
01:03:51.920
It was a rather philosophically nice picture.
link |
01:03:55.000
It was disproved when the Big Bang, well, when I say the Big Bang, this was theoretically
link |
01:04:03.480
discovered by people trying to solve Einstein's equations and apply it to cosmology.
link |
01:04:09.720
Einstein didn't like the idea.
link |
01:04:10.720
He liked a universe which was there all the time and he had a model which was there all
link |
01:04:16.040
the time.
link |
01:04:17.040
But then there was this discovery, accidental discovery, very important discovery of this
link |
01:04:22.600
microwave background.
link |
01:04:25.280
And if there's the crackle on your television screen, which is already sensing this microwave
link |
01:04:31.920
background, which is coming at us from all directions, and you can trace it back and
link |
01:04:36.440
back and back and back, then it came from a very early stage of the universe, well,
link |
01:04:42.040
it's part of the Big Bang theory.
link |
01:04:43.720
The Big Bang theory was when people tried to solve Einstein's equations.
link |
01:04:47.720
They really found you had to have this initial state where the universe, it was used to
link |
01:04:51.960
be called the primordial atom and things like this.
link |
01:04:55.720
This Friedman and Lemaitre, Friedman was a Russian, Lemaitre was a Belgian, and they
link |
01:05:01.840
independently, well, basically Friedman first, and Lemaitre talked about the initial state,
link |
01:05:08.920
which is a very, very concentrated initial state, which seemed to be the origin of the
link |
01:05:12.560
universe.
link |
01:05:13.560
Primordial atom.
link |
01:05:14.560
Primordial atom is what he called it, yes.
link |
01:05:16.960
Beautiful term.
link |
01:05:17.960
And then it became, well, Fred Hoyle used the term Big Bang in a kind of derogatory
link |
01:05:21.920
sense.
link |
01:05:22.920
He said, well, didn't he have that?
link |
01:05:23.920
Just like with the shorting of the cats, right?
link |
01:05:24.920
Yes.
link |
01:05:25.920
It sort of got picked up on, whereas it wasn't his intention originally, but then the evidence
link |
01:05:31.800
piled up and piled up, and one of my friends I learned a lot from, and when I was in Cambridge
link |
01:05:37.160
with Dennis Sharma, he was a very proponent of steady state, and then he got converted
link |
01:05:41.920
and said, no, I'm sorry, I had a great respect for him.
link |
01:05:44.520
He went around lecturing and said, I was wrong.
link |
01:05:46.880
This steady state model doesn't work.
link |
01:05:49.040
There was this Big Bang, and this microwave background that you see, okay, it's not actually
link |
01:05:54.400
quite the Big Bang, when I said not quite.
link |
01:05:56.760
It's about 380,000 years after the Big Bang, but that's what you see.
link |
01:06:01.560
But then you have to have had this Big Bang before it in order to make the equations work,
link |
01:06:05.920
and it works beautifully, except for one little thing, which is this thing called inflation,
link |
01:06:11.120
which people had to put into it to make it work.
link |
01:06:14.200
When I first heard of it, I didn't like it at all.
link |
01:06:17.000
What's inflation?
link |
01:06:18.000
Inflation is it in the first, I'm going to give you a very tiny number.
link |
01:06:22.840
Think of a second.
link |
01:06:23.840
That's not very long.
link |
01:06:24.840
Now, I'm going to give you a fraction of a second, one over a number.
link |
01:06:29.520
This number has 32 digits between, well, let's say between 36 and 32 digits, tiny, tiny time
link |
01:06:39.360
between those two, tiny, ridiculous seconds, fraction of a second.
link |
01:06:44.520
The universe was supposed to have expanded in this exponential way, an enormous way.
link |
01:06:49.760
For no apparent reason, you had to invent a particular thing called the inflaton field
link |
01:06:54.640
to make it do it, and I thought this is completely crazy.
link |
01:06:58.280
There are reasons why people stuck with this idea.
link |
01:07:02.040
You see, the thing is that I've formed my model for reasons which are very fundamental,
link |
01:07:06.520
if you like, it has to do this very fundamental principle, which is known as the second law
link |
01:07:12.080
of thermodynamics.
link |
01:07:13.080
The second law of thermodynamics says, more or less, things get more and more random as
link |
01:07:17.720
time goes on.
link |
01:07:19.200
Now, another way of saying exactly the same thing is things get less and less random as
link |
01:07:24.360
things go back.
link |
01:07:25.360
As you go back in time, they get less and less random.
link |
01:07:27.560
So you go back and back and back and back, and the earliest thing you can directly see
link |
01:07:31.880
is this microwave background.
link |
01:07:34.760
What's one of the most striking features of it is that it's random.
link |
01:07:39.280
It has what you call this spectrum, which is what's called the Planck spectrum, of frequencies,
link |
01:07:48.040
different intensities for different frequencies, and there's this wonderful curve, there's
link |
01:07:51.880
a max Planck, and what's it telling you?
link |
01:07:54.720
It's telling you that the entropy is at a maximum, start is off at a maximum, and it's
link |
01:08:00.040
going up over since.
link |
01:08:02.040
I call that the mammoth in the room, I mean, it's a paradox.
link |
01:08:05.400
The mammoth, yes, it is.
link |
01:08:07.160
And so people, why don't cosmologists worry about this?
link |
01:08:10.560
So I worried about it, and then I thought, well, it's not really a paradox because you're
link |
01:08:16.680
looking at matter and radiation at a maximum entropy state.
link |
01:08:20.800
What you're not seeing directly in that is the gravitation.
link |
01:08:25.480
It's gravitation, which is not thermalized.
link |
01:08:28.560
The gravitation was very, very low entropy, and it's low entropy by the uniformity, and
link |
01:08:34.560
you see that in the microwave too.
link |
01:08:36.040
It's very uniform over the whole sky.
link |
01:08:38.200
I'm compressing a long story into a very short few sentences.
link |
01:08:40.880
And doing a great job, yeah.
link |
01:08:42.120
So what I'm saying is that there's a huge puzzle.
link |
01:08:45.880
Why was gravity in this very low entropy state, very high organized state, everything
link |
01:08:53.680
else was all random, and that, to me, was the biggest problem in cosmology.
link |
01:08:59.040
The biggest problem, nobody seems to even worry about it.
link |
01:09:02.560
People say they solved all the problems and they don't even worry about it.
link |
01:09:05.560
They think inflation sources, it doesn't, it can't, because it's just...
link |
01:09:12.440
Just to clarify, that was your problem with the inflation describing some aspect of the
link |
01:09:18.800
moment right after the Big Bang?
link |
01:09:20.960
Expansion is supposed to stretch it out and make it all uniform, you see.
link |
01:09:24.040
It doesn't do it, because it can only do it if it's uniform already at the beginning.
link |
01:09:27.960
You just have to look, I can't go into the details, but it doesn't solve it, and it was
link |
01:09:31.960
completely clear to me it doesn't solve it.
link |
01:09:33.960
But where does the conformal cyclic cosmology of starting to talk about something before
link |
01:09:39.680
that singularity?
link |
01:09:40.680
Well, I began, I was just thinking to myself, how boring this universe is going to be.
link |
01:09:47.760
We got this exponential expansion, this was discovered early in this 21st century.
link |
01:09:56.960
People discovered that these supernova exploding stars showed that the universe is actually
link |
01:10:03.960
undergoing this exponential expansion.
link |
01:10:07.560
So it's a self similar expansion.
link |
01:10:10.920
And it seems to be a feature of this term that Einstein introduced into his cosmology
link |
01:10:17.000
for the wrong reason.
link |
01:10:18.640
He wanted a universe that was static.
link |
01:10:20.680
He put this new term into his cosmology to make it make sense.
link |
01:10:24.480
It's called the cosmological constant.
link |
01:10:26.720
And then when he got convinced that the universe had a Big Bang, he retracted it, complaining
link |
01:10:31.360
that this was his greatest blunder.
link |
01:10:33.360
The trouble is it wasn't a blunder, it was actually right, very ironic.
link |
01:10:38.040
And so the universe seems to be behaving with this cosmological constant.
link |
01:10:42.000
Okay.
link |
01:10:43.000
So this universe is expanding and expanding.
link |
01:10:45.240
What's going to happen in the future?
link |
01:10:46.760
Well, it gets more and more boring for a while.
link |
01:10:48.920
What's the most interesting thing in the universe?
link |
01:10:50.640
Well, there's black holes.
link |
01:10:51.880
The black holes more or less gulp down in entire clusters of galaxies.
link |
01:10:55.880
It'll swallow up most of our galaxy.
link |
01:10:59.120
We will run into our Andromeda galaxy's black hole.
link |
01:11:01.520
That black hole will swallow our one, they'll get bigger and bigger, and they'll basically
link |
01:11:05.740
swallow up the whole cluster of galaxies.
link |
01:11:09.240
Gulp it all down pretty well all.
link |
01:11:11.360
Most of it, maybe not all.
link |
01:11:13.160
Most of it.
link |
01:11:14.160
They'll be just these black holes or I'm pretty boring, but still not as boring as
link |
01:11:18.400
it's going to get.
link |
01:11:19.400
It's going to get more boring because these black holes, you wait, you wait, and you wait,
link |
01:11:23.160
and you wait, and you wait, and unbelievable length of time.
link |
01:11:26.420
And Hawking's black hole evaporation starts to come in.
link |
01:11:30.080
And the black holes, you just, it's a clenum riteidus.
link |
01:11:34.820
Finally evaporate away.
link |
01:11:36.440
Each one goes away.
link |
01:11:37.440
It disappears with a pop at the end.
link |
01:11:39.760
What could be more boring?
link |
01:11:40.760
it was boring then. Now this is really boring. There's nothing, not even black holes.
link |
01:11:46.360
The universe gets colder and colder and colder and colder. And I thought,
link |
01:11:49.880
this is very, very boring. Now that's not science, is it? But it's emotional. So I thought, who's
link |
01:11:57.480
going to be bored by this universe? Not us, we won't be around. It'll be mostly photons running
link |
01:12:02.920
around. And what do photons do? They don't get bored because it's part of relativity, you see.
link |
01:12:08.600
It's not really that they don't experience anything. That's not the point. The photons get
link |
01:12:13.880
right out to infinity without experience any time. It's the way for where relativity works.
link |
01:12:20.760
And this was part of what I used to do in my old days when I was looking at gravitational
link |
01:12:24.440
radiation and how things behaved in infinity. Infinity is just like another place. You can
link |
01:12:30.200
squash it down. As long as you don't have any mass in the world, infinity is just another place.
link |
01:12:36.280
The photons get there. The gravitons get there. What do they get? They run to infinity. They say,
link |
01:12:42.360
well, now I'm here, what do I do? There's something on the other side, is there? The usual view,
link |
01:12:47.240
it's just a mathematical notion. There's nothing on the other side. That's just the boundary of it.
link |
01:12:51.560
A nice example is this beautiful series of pictures by the Dutch artist MC Escher. You may
link |
01:12:57.400
know them. The one's called Circle Limits. They're a very famous one with the angels and the devils.
link |
01:13:02.280
And you can see them crowding and crowding and crowding up to the edge. Now, the kind of geometry
link |
01:13:07.320
that these angels and devils inhabit, that's their infinity. But from our perspective,
link |
01:13:13.960
infinity is just a place. Can you just take a brief pause and just the word you're saying,
link |
01:13:22.680
infinity is just a place. For the most part, infinity is a mathematical concept.
link |
01:13:31.000
I think this is one of the things. You think there's an actual physical
link |
01:13:34.440
manifesto. In which way does infinity ever manifest itself in our physical universe?
link |
01:13:39.960
Well, it does in various places. It's a thing that, if you're not a mathematician, you think,
link |
01:13:44.520
oh, infinity, I can't think about that. Mathematicians think about infinity all the time.
link |
01:13:48.520
They get used to the idea, and they just play around with different kinds of infinities,
link |
01:13:52.200
and it becomes no problem. But you just have to take my word for it. Now, one of the things is,
link |
01:13:58.360
you see, you take a Euclidean geometry. Well, it just keeps on going, and it goes out to infinity.
link |
01:14:04.440
Now, there's other kinds of geometry, and this is what's called hyperbolic geometry. It's a bit
link |
01:14:09.560
like Euclidean geometry. It's a little bit different. It's like what Asher was trying to
link |
01:14:13.960
describe in his angels and devils. And he learned about this from Coxeter. And he
link |
01:14:21.480
think that's a very nice thing. I try and represent this infinity to this kind of geometry.
link |
01:14:26.600
So it's not quite Euclidean geometry. It's a bit like it, that the angels and the devils
link |
01:14:30.520
inhabit. And their infinity, by this nice transformation, you squash their infinity down
link |
01:14:37.560
so you can draw it as this nice circle boundary to their universe. Now, from our outside perspective,
link |
01:14:45.080
we can see their infinity as this boundary. Now, what I'm saying is that it's very like that.
link |
01:14:52.120
The infinity that we might experience like those angels and devils in their world
link |
01:14:58.920
can be thought of as a boundary. Now, I found this a very useful way of talking about
link |
01:15:05.720
radiation, gravitational radiation, and things like that. It was a trick, mathematical trick.
link |
01:15:12.360
So now what I'm saying is that that mathematical trick becomes real, that somehow the photons,
link |
01:15:19.080
they need to go somewhere. Because from their perspective, infinity is just another place.
link |
01:15:26.680
Now, this is a difficult idea to get your mind around. So that's why one of the reasons
link |
01:15:33.240
cosmologists are finding a lot of trouble taking me seriously. But to me, it's not such a wild
link |
01:15:39.000
idea. What's on the other side of that infinity? You have to think, why am I allowed to think of
link |
01:15:44.520
this? Because photons don't have any mass. And we in physics have beautiful ways of measuring time.
link |
01:15:53.400
They're incredibly precise clocks, atomic and nuclear clocks, unbelievably precise. Why are
link |
01:15:59.720
they so precise? Because of the two most famous equations of 20th century physics.
link |
01:16:05.880
One of them is Einstein's E equals MC squared. What's that tell us? Energy and mass are equivalent.
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01:16:14.680
The other one is even older than that. Still 20th century, only just. Max Planck E equals H nu.
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Nu is a frequency. H is a constant again, like C. E is energy. Energy and frequency are equivalent.
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Put the two together. Energy and mass are equivalent. Einstein, energy and frequency are
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equivalent. Max Planck, put the two together. Mass and frequency are equivalent. Absolutely basic
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physical principle. If you have a massive entity, a massive particle, it is a clock with a very,
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very precise frequency. It's not, you can't directly use it. You have to scale it down,
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so your atomic and nuclear clocks. But that's the basic principle. You scale it down to some
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that you can actually perceive. But it's the same principle. If you have mass, you have beautiful
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clocks. But the other side of that coin is, if you don't have mass, you don't have clocks.
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If you don't have clocks, you don't have rulers. You don't have scale.
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So you don't have space and time. You don't have a measure of the scale of space and time.
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So you have to, you do have the structure, what's called the conformal structure. You see,
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it's what the angels and devils have. If you look at the eye of the devil, no matter how close to
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the boundary it is, it has the same shape, but it has a different size. So you can scale up and
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you can scale down, but you mustn't change the shape. So it's basically the same idea,
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but applied to space time now. In the very remote future, you have things which don't measure the
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scale, but the shape, if you like, is still there. Now that's in the remote future. Now I'm going to
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do the exact opposite. Now I'm going to go way back into the Big Bang. Now as you get there,
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things go hotter and hotter, denser and denser. What's the universe dominated by? Particles moving
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around almost with the speed of light. When they get almost with the speed of light, okay,
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they begin to lose the mass too. So for a completely opposite reason, they lose the sense of scale as
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well. So my crazy idea is the Big Bang and the remote future, they seem completely different.
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One is extremely dense, extremely hot. The other is very, very rarefied and very, very cold,
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but if you squash one down by this conformal scaling, you get the other. So although they
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look and feel very different, they're really almost the same. The remote future on the other
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side, and claiming as that, where do the photons go? They go into the next Big Bang.
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You've got to get your mind around that crazy idea. Taking a step on the other side of the place that
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is infinity. Okay. So I'm saying the other side of our Big Bang, now I'm going back into the Big
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Bang, there was the remote future of a previous Eon. And what I'm saying is that previous Eon,
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there are signals coming through to us, which we can see and which we do see. And these are
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both signals, the two main signals are to do with black holes. One of them is the collisions
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between black holes. And as they spiral into each other, they release a lot of energy in
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the form of gravitational waves. Those gravitational waves get through in a certain form into the next
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Eon. That's fascinating that there's some, maybe you can correct me if I'm wrong, but that means
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that some information can travel from another Eon. Exactly. That is fascinating. I've seen
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somewhere described sort of the discussion of the Fermi paradox, that if there's intelligent life,
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yes, communication immediately takes you there. We have a paper, my colleague,
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Vaheguzha Jan, who I've worked with on these ideas for a while, we have a crazy paper on that,
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yes, looking at the Fermi paradox, yes. Right. So if the universe is just cycling over and over
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and over, punctuated by the singularity of the Big Bang, and then intelligent or any kind of
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intelligent systems can communicate through from Eon to Eon, why haven't we heard anything from
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our alien friends? Because we don't know how to look. That's fundamentally the reason. I don't
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know, you see, it's speculation. I mean, the SETI program is a reasonable thing to do,
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but still speculation. It's trying to say, okay, maybe not too far away with a civilization which
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got there first, before us, early enough that they could send us signals, but how far away would you
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need to go before? I mean, I don't know. We have so little knowledge about that. We haven't seen
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any signals yet, but it's worth looking. It's worth looking. And what I'm trying to say, here's another
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possible place where you might look. Now, you're not looking at civilizations which got there first.
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You're looking at those civilizations which were so successful, probably a lot more successful than
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there were likely to be by the looks of things, which knew how to handle their own global warming
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or whatever it is, and to get through it all and to live to a ripe old age in the sense of a civilization
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to the extent that they could harness signals, that they could propagate through for some reason
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of their own desires, whatever we wouldn't know, to other civilizations which might be able to pick
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up the signals. But what kind of signals would they be? I am a foggiest.
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Let me ask the question. What do you use the most beautiful idea in physics or mathematics or the
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art at the intersection of the two? I'm going to have to say complex analysis.
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I might have said infinities. One of the most single most beautiful idea, I think, was the fact
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that you can have infinities of different sizes and so on. But that's, in a way, I think, complex
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analysis. It's got so much magic in it. It's a very simple idea. You take numbers, you take
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the integers and then you fill them up into the fractions and the real numbers. You imagine you're
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trying to measure a continuous line and then you think of how you can solve equations. Then what
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about x squared equals minus one? Well, there's no real number which has satisfied that. So you
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have to think of, well, there's a number called i. You think you invent it. Well, in a certain sense,
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it's there already. But this number, when you add that square root of minus one to it, you have
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what's called the complex numbers. And they're an incredible system. If you like, you put one little
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thing in, you put square root of minus one in and you get how much benefit out of it, all sorts of
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things that you'd never imagined before. And it's that amazing, all hiding there in putting that
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square root of minus one in. So in a sense, I think that's the most magical thing I've seen in
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mathematics or physics. And it's in quantum mechanics. In quantum mechanics. You see, it's
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there already. You might think, what's it doing there? Okay, just a nice beautiful piece of
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mathematics. And then suddenly we see, nope, it's the very crucial basis of quantum mechanics.
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It's there in the way the world works. So on the question of whether math is discovered or
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invented, it sounds like you may be suggesting that partially it's possible that math is indeed
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discovered. Oh, absolutely. Yes. No, it's more like archaeology than you might think. Yes.
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Yes. So let me ask the most ridiculous, maybe the most important question. What is the meaning of
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life? What gives your life fulfillment, purpose, happiness and meaning? Why do you think we're
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here on this? Given all the big bang in the infinities of photons that we've talked about?
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All I would say, I think it's not a stupid question. I mean, there are some people, you know, many of
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my colleagues, new scientists, and they say, well, that's a stupid question, meaning we're just here
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01:24:32.440
because things came together and produced life and so what. I think there's more to it. But what
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there is, that's more to it. I have really much idea. And it might be somehow connected to the
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01:24:44.600
mechanisms of consciousness that we've been talking about, the mystery there. Yeah. It's connected
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with all sorts of, yeah, I think these things are tied up in ways which, you see, I tend to think
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the mystery of consciousness is tied up with the mystery of quantum mechanics and how it
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01:25:02.200
fits in with the classical world. And that's all to do with the mystery of complex numbers.
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01:25:08.280
And there are mysteries there, which look like mathematical mysteries, but they seem to have
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a bearing on the way the physical world operates. We're scratching the surface. We have a long,
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long, huge way to go before we really understand that. And it's a beautiful idea that the depth,
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01:25:28.040
the mathematical depth could be discovered. And then there's tragedies of ghettos and
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01:25:32.840
completeness along the way that we'll have to somehow figure our ways around. Yeah.
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01:25:38.680
So, Roger, it was a huge honor to talk to you. Thank you so much for your time today.
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01:25:43.240
It's been my pleasure. Thank you. Thanks for listening to this conversation with Roger Penrose
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01:25:48.760
and thank you to our presenting sponsor, Cash App. Please consider supporting this podcast by
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01:25:53.880
getting ExpressVPN at expressvpn.com slash lexpod and downloading Cash App and using code Lex Podcast.
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01:26:03.640
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01:26:08.840
support on Patreon, or simply connect with me on Twitter at Lex Freedman.
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01:26:13.720
And now let me leave you with some words of wisdom that Roger Penrose wrote in his book,
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01:26:19.080
The Emperor's New Mind. Beneath all this technicality is the feeling that it is indeed,
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quote unquote, obvious, that the conscious mind cannot work like a computer, even though much
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of what is involved in mental activity might do so. This is the kind of obviousness that a child
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can see, though the child may later in life become browbeaten into believing that the obvious problems
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are quote unquote, non problems to be argued into nonexistence by careful reasoning and
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clever choices of definition. Children sometimes see things clearly that are obscured in later life.
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01:26:58.840
We often forget the wonder that we felt as children when the cares of the quote unquote
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real world have begun to settle on our shoulders. Children are not afraid to pose basic questions
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01:27:10.280
that may embarrass us as adults to ask. What happens to each of our streams of consciousness
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after we die? Where was it before we were born? Might we become or have been someone else?
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01:27:22.920
Why do we perceive it all? Why are we here? Why is there a universe here at all in which we can
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actually be? These are puzzles that tend to come with the awakenings of awareness in any of us,
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and no doubt with the awakening of self awareness within whichever creature or
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other entity it first came. Thank you for listening and hope to see you next time.