00:00:00.000 So we spoke about superintelligence the last time and we concluded that there can't be
00:00:21.200 such a thing as superintelligence because there's an underlying universality underlying
00:00:26.800 the human mind and every other intelligence artificial or not would have that in common with us
00:00:34.480 so and as you said earlier in that interview there there can be no such thing as something to us
00:00:41.120 as we are to apes for example. So this brings us to the question of our role in the cosmos in general
00:00:50.000 so for example you say that you know for centuries we believe that we were at the center of the
00:00:56.800 universe and that the sun revolved around us and the stars revolved around us and that there were
00:01:02.480 gods who who take great interest in what we down here on earth do excuse me what we do so
00:01:09.360 everything was about us so this is anthropocentrism the idea that people are at the center
00:01:15.760 that the most important thing and most explanations of everyday phenomena were anthropocentric
00:01:22.880 but nowadays many people in the west have since decided not to to take anthropocentric approaches
00:01:30.560 and now our most fundamental explanations don't involve humans at all you know our best
00:01:34.800 explanation in physics are about things like forces or space and time and whatnot so one could
00:01:41.920 conclude as many scientifically-minded people do nowadays that people are not that important at
00:01:46.240 all but you take issue with this yes and the fact that there are only two kinds of entities
00:01:53.920 in the world the ones that can create knowledge and the ones that don't create explanatory
00:01:59.520 knowledge and the ones that don't the connection between those two things is via the laws of physics
00:02:07.360 via the universality of the laws of physics the universality that links us with all possible
00:02:14.640 AGIs extraterrestrial intelligence and so on the the universality that connects us with them
00:02:25.200 is precisely the universality of the laws of physics so so it's it's uh an interesting fact
00:02:33.440 that that we got to the concept of universal laws of physics by by more and more distancing ourselves
00:02:42.400 from anthropocentrism when we had completely finished this process and got round to the modern
00:02:51.040 concept of the universal laws of physics universal laws of computation of evolution and so on
00:02:57.040 we finally got round to realizing that that puts us at the center of things in a completely
00:03:05.280 different way or I would say two ways one is that because of like the testability that scientific
00:03:17.200 theories have that produces a link between understanding the world and controlling it because
00:03:25.840 controlling it is is always putting to the test and understanding of it and the understanding
00:03:33.120 has got to be testable therefore we can control more and more of the world the more of it we
00:03:38.800 understand but there's also the other way round that simply to understand humans and I put this
00:03:47.200 argument in the book uh simply to understand humans one must understand the laws of physics
00:03:53.760 in their entirety because in order to understand as I say in the book when the team of scientists
00:04:04.320 are going to pop the champagne cork and regard that as a physical system you want to predict when
00:04:10.560 it will when or whether it will pop the champagne cork you must understand whether they are going
00:04:19.200 to succeed in understanding the thing they're trying to understand which could be anything
00:04:25.760 it could be something about distant galaxies it could be something about quarks
00:04:31.040 and it could be something about biology or about morality or whatever when they succeed they
00:04:39.280 will publish and pain cork if you want to predict that you need to know the truth of the matter
00:04:43.760 that they are investigating so to understand humans just humans you need to understand everything
00:04:50.400 and converse as I said initially humans on the other hand can affect anything and eventually
00:04:59.200 control anything that's controllable so humans play a central role in the cosmos perhaps the
00:05:05.600 the most significant role that anything could play yes uh I think that it's a candidate for the most
00:05:12.880 significant I mean if someone says oh no well it's spacetime is the most significant well maybe but
00:05:18.080 but uh certainly humans are up there in that they are completely indispensable for understanding
00:05:24.400 anything ultimately let's get to the multiverse you are a famous proponent of the so-called
00:05:31.520 many universes interpretation interpretation of quantum physics how is this interpretation
00:05:38.160 different from like what are the contenders and how is it different from from them
00:05:43.920 well as you've just indicated with your with your air quotes um I don't think there are any other
00:05:50.320 contenders there are various versions of uh this many worlds or many universe interpretation really
00:05:59.120 it's should be called a variety in quantum theory it's not an interpretation it's just what
00:06:05.360 the quantum theory says when taken seriously there are several different versions of it including
00:06:12.960 rather far removed ones but in order to explain what brings about the experimental results
00:06:25.440 that we see in just ordinary quantum optics laboratories one must take on board
00:06:32.880 the multiplicity of reality that is that when we do the experiment there are many of us many
00:06:41.600 instances of us doing the experiment in parallel or in almost parallel um you can predict the
00:06:51.760 results without assuming that but that's just an empty prediction it doesn't explain how they
00:06:59.280 come about and science should be about and therefore it doesn't involve any understanding
00:07:06.160 it just involves predicting just as uh I might tell somebody how to switch my tv on
00:07:16.320 and how to reach a certain channel but that is completely different from explaining to them how
00:07:22.320 tv works or understanding how it works or from building a better tv you cannot build a better tv
00:07:31.600 just being just by being told what will happen when you press the remote and it's the same with
00:07:37.920 physics in general so we need this this multiplicity of universes of realities or whatever you
00:07:47.920 want to call them we don't have good language for it yet or our our languages is built on the
00:07:54.560 assumption that only one thing happens but in fact many things happen and we understand it very
00:08:00.160 well now we understand it for example much better than ever it himself did in the 1950s and it
00:08:07.040 is simply the only contender for an explanation of what happens to bring about the experimental results
00:08:15.760 now you say in the chapter about the multiverse that every fiction that does not violate the
00:08:23.200 laws of physics is fact why is that the case that is the case because physical objects do not
00:08:32.400 have sharp positions that is when I say sharp I mean sharp means in this terminology the same
00:08:41.600 in all universes so the laws of physics the laws of quantum physics require that there is no such
00:08:51.760 thing as a completely sharp position of a particle or of a person and no such thing as a completely
00:08:59.840 sharp configuration of a person or of their thoughts and so there are always a few universes
00:09:08.720 doing maverick things when I say a few I really mean a tiny number like two to the minus
00:09:16.480 two to the power of a hundred or something of the really maverick ones but still that's not zero
00:09:22.880 so this doesn't affect things like decisions it doesn't affect what we should do when we're
00:09:29.440 betting on poker games or horse races but it does mean that if you're talking about
00:09:38.240 existence very strange things exist somewhere in the multiverse now having stressed that point
00:09:48.400 let me just claw that back a little in regard to the brain and in regard to thinking
00:09:55.040 because thinking is an error correction process and there are errors arising constantly in
00:10:03.360 the brain glitches electrical glitches and also glitches due to a failed temporary failed understanding
00:10:12.880 where we were which we later correct either by purely hardware methods where we know the
00:10:20.000 neurons the majority of neurons are saying that the minority are wrong and because we we recognize
00:10:25.520 errors and so the number of the proportion of universes in which our brain does something maverick
00:10:34.800 are exponentially smaller again because error correction is exponentially efficient and by the
00:10:42.240 way that that is true whether we are classical computers or quantum computers so really for all
00:10:49.440 practical purposes the existence of maverick versions of ourselves are is negligible but they
00:10:58.880 are there and that's why I said that they are there in other words all stories that do not
00:11:08.640 violate the laws of physics happen somewhere but the ones that do violate the laws of physics
00:11:16.240 don't happen because they are uniform that they are universal they they uniform across the
00:11:23.120 multiverse so I mean this is fascinating because it does mean that every every book you've read
00:11:29.520 every movie you've seen if the plot doesn't violate the laws of physics it really has happened
00:11:36.880 or does currently happen somewhere in the multiverse except it's not a movie it's real
00:11:42.720 yes the error correction idea applies there too not just in the brain but in in a book or movie
00:11:54.000 if the book let's say is about someone doing magic like Harry Potter or something
00:12:01.600 then although it can't happen that real magic occurs in in these maverick universes
00:12:07.680 by the way the term maverick universes I think was invented by Bryce DeWitt my former boss in
00:12:15.680 University of Texas it just seems to have happened because something isn't really levitating it's
00:12:23.360 just that the atoms in the room happen to strike the apparently levitating object in just the
00:12:30.080 right ways to keep it levitating thing is those those universes aren't really universes because
00:12:40.480 the very next thing that will happen in the vast majority of those is that the levitated object
00:12:45.920 will fall to the ground and that is because the apparent explanation of what was holding it up
00:12:53.520 namely magic isn't true what was holding it up was just accident if you think that
00:13:01.040 a something deserves to be called a universe or universe in which a particular story happens
00:13:08.320 if you think that that only deserves to be called that if the story can if the explanations in
00:13:14.320 the story are true in that universe then these Harry Potter type universes aren't universes at all
00:13:22.080 they are just want to be universes they're just bits of the multiverse we know anyway that
00:13:30.480 that there are many bits of the multiverse that aren't universes universes are large scale
00:13:36.320 structures in the multiverse but there's plenty happening there that that it can't be thought
00:13:43.840 of as universes so the the Harry Potter ones are among those two this opens up a possibility
00:13:50.080 for some interesting thought experiments for example and you write in the book about the problem
00:13:54.640 of aging for example and you write that you hope that one day we will solve this problem I hope
00:13:59.680 so too and and the problem of death more generally curing death is not against the laws of physics
00:14:07.280 somewhere in the universe it it happens and it's already happened somewhere in the multiverse
00:14:12.480 sorry yes somewhere in the multiverse and it it also happens where people very much like us do it
00:14:21.120 and couldn't we conclude that we don't really need to worry about death even right now
00:14:26.960 even though we haven't solved death you because you could imagine another universe where it's
00:14:30.800 exactly the same you with all the same memories all the same contents of your mind and that
00:14:37.280 universe in our universe are exactly the same up until the point where people cure death so you
00:14:44.160 do get to survive it's just in a different universe that seems unlikely I mean those of us who read
00:14:50.640 say scientific American will will have seen hints that this was going to happen
00:14:59.120 and therefore will be different there's also another problem which is that it is not yet known
00:15:08.960 how to understand the issue of personal identity across the multiverse should somebody who
00:15:17.120 accidentally turns out to have my exact state of mind be regarded as just another instance of me
00:15:25.120 just like the ones that have a common origin with me they are the same for a reason
00:15:32.640 the ones that are the same by accident is that the same as the ball being held up by Harry Potter
00:15:38.240 magic in other words not me just looks like me or is it me because anybody who has my state of
00:15:46.480 mind has my exact state of mind really is me we don't know yet one has to work extremely hard to
00:15:55.840 make sense of probability and decision making in the multiverse I know because I've worked extremely
00:16:03.360 hard to make sense of it and to make sense of personal identity as well is a harder problem
00:16:11.600 in my view but it will be done and we're understanding more and more about the multiverse over time
00:16:20.560 now in a similar vein the origin of life is still a mystery there are some good explanations you
00:16:27.280 cite one the RNA world hypothesis in your book but it's still a mystery as to why is it that life
00:16:33.520 arose when it did and you know what were the conditions that led to that but in the same vein
00:16:40.800 you could ask well the formation of life is not against the laws of physics clearly because we're
00:16:44.800 alive and if it's not against the laws of physics well then it has to happen somewhere in the
00:16:49.360 multiverse and it is only in universes where the formation of intelligent life in particular happens
00:16:54.960 that somebody even wonders why it's there yes but as I also write in book that by itself which is
00:17:04.640 which is what they call an anthropic argument in my view isn't enough to explain anything
00:17:11.040 I think it can form part of an explanation of things but it can never be the whole explanation
00:17:17.360 because if it were the whole explanation of for example why life formed then one can show by a
00:17:25.280 simple argument due to my other old boss Dennis Sharma that it only just happened that the laws
00:17:34.560 the initial conditions whatever the state of the planet and so on in the vast majority of cases
00:17:43.520 where that was the only explanation for why life formed it only just formed and if it only just
00:17:52.080 formed it's a bit hard to see why it won't be snuffed out in the next moment so I mean that's
00:18:02.160 not a watertight argument but it kind of takes the wind out of the sails of the anthropic
00:18:10.400 argument one really needs something else another reason why we should be looking for something
00:18:16.480 else is that an anthropic argument is kind of giving up it's kind of saying you know where
00:18:24.240 it's not due to a law of physics it's not due to some new principle that are along the same
00:18:30.400 lines as the principle of evolution which explained so wonderfully what we're previously
00:18:37.680 mysteries about about life it's just that if it weren't so we wouldn't be asking well I think
00:18:45.680 that should be regarded as not good enough right okay let's wrap it up here again this was a
00:18:54.720 follow-up interview to the first interview we did in German for the translation of David Deutsch's
00:19:00.240 book the beginning of infinity it is now available in German titled Down Fungdon Antlichkite
00:19:07.760 and it's about so much more than what we just discussed we really only scratched the surface here
00:19:13.040 it's also about good versus bad philosophy how to make decisions rationally why flowers are
00:19:20.000 beautiful how cultures evolved how our species evolved the problem of sustainability again it's a
00:19:27.280 wonderful book fascinating read and I encourage our German speaking viewers and listeners to read
00:19:33.680 the book it's guaranteed to change your your world view it was fascinating speaking with you
00:19:39.680 nice time to you and let's see how the German edition does
