Q&A - What We Cannot Know - with Marcus du Sautoy

[Music] so what do you think in this in the puzzle of consciousness because I remember sort of starting out as a science writer more than 20 years ago and sort of excitedly going to visit the states and because they're all these scientists suddenly getting very excited about consciousness do you think that is something that will become knowable in our lifetimes I think already in the last few years I mean it was very exciting because that story is one that's really happening now and changing every every year new insights into what consciousness might be and I I think that already we've learnt a lot I mean I actually one of the tricks about being a mathematician sometimes is if you want to understand something often it's very clever trick and this is worth remembering it is to try and look actually the opposite thing and try and understand when something isn't that so I think some of the most exciting kind of investigations have been looking at for example the brain when it's conscious and then when it goes for example at night time into deep stage for sleep and it's totally unconscious and actually in the book I sort of talked to a guy Giulio Tononi who actually has managed to understand the change in the network from your conscious state to your your deep unconscious state which you know clearly is an important factor in then being something important to consciousness and he's been able to oppose why I really laughed him is that he articulated it in a mathematical formula so what it means to be me is now you know when I'm conscious this this coefficient is called Phi is very high and then the net the nature of the network sort of there's almost like the network goes down and the connections go and that's what's responsible for you becoming unconscious um but it means we've got now a kind of tool which might give us a measure of say when a when a network like an iPhone or a city or an audience might have a small elevated level of collective consciousness but I still think it's that challenge I don't think that still aren't you know if you talk to the real hardcore mysterion's they're called actually the those who say well that doesn't excuse shown a correlation between but that doesn't show why this thing you know and it still went on so even if my iPhone has this network how can I it's going to be in what could well be saying can i unconscious you know don't rush me but it might have no internal structure to it at all internal world at all I'm going to switch mine off anyway we'd love for you to ask your questions yeah we've got some microphones I think somewhere if you could make yourself known please raise your hand and let's get some questions getting cuz often these really great great parts of things right okay there's one there's a chap in the middle there I've very conveniently gone for a person in the middle the young chap in the jacket the black jacket what's the difference between consciousness and self-consciousness well I think one of the challenges is really trying to articulate what we mean by this so so I think that one of the other experiments I looked at is the idea of I mean self-awareness maybe the sense of yourself and there's a very interesting again one of the challenges okay what animals have a level of consciousness like ours and how can you ask an animal that and so one of the tests is a dozen animal recognize that there's somebody in the mirror is actually themselves try that sound have a sense of consciousness will allow you to recognize that that is an image of yourself and so Gordon Gallup animal behaviorist came up with this interesting experiment that they put a actually I can show you it and it's they put a little yellow dots arm on the forehead so here's here's some some chimpanzees in front of the mirror so that do these chimps actually recognize that the image that they're look is some sense or do they think that that's another animal I think that's a kind of first level of and I think it's like your self-awareness it may not be quite full consciousness but you know for example this little monkey here there's getting used to get used to the mirror but you know as it does these kind of dancing dancing moves you know is it things like dancing with another chimp or so the thing was a Gordon gallic came up with this idea that you would put a yellow mark such they didn't realize that it had been put there and then there are the responses when it sees itself in the mirror what we'll how we're always fond will it say oh that one's got a funny mark on it or when it's actually wonder what's on my foreheads so interesting the orangutan and the chimpanzees are the only two species along with ours so you hear you guys he's looking inside the mirror and saying this is really weird there's something on my forehead so it's actually very small number of species that have this kind of sense of self-awareness okay this is to do with vision so you might say a dog might have a different kind of thing you know the this orangutan is really pissed off ideas like that but again you can ask this with children so we've done experiments and we're what point does a child recognize their mirror images them themselves and that's really interesting cuz you've got an evolving changing brain and so if you put like a 14 month old in front of the the mirror they touch the mirror and they go around behind the mirror and try and see but have you put in like a 18 to 22 month old there's a kind of something changes in the brain which causes a recognition that that's himself then they'll immediately go why is this on myself so that I think those are the interesting moments you know what is the change in the brain which causes a sense of self there but I think that's you know perhaps I think we all know what consciousness is I mean that's what Descartes statement is the only thing I'm sure of in this world is I think therefore I am but they're still articulating what that is I think is almost the challenge of this whole edge let's take em another question it's this one here and please yeah sorry who's got the microphone yes sorry how much of this do you think is due to the limitations of human intelligence and there's things that are potentially Noble and aliens may know but just like I can't you might teach my dog quantum mechanics we just can't know them yes I mean I certainly sort of explored that idea you know the capacity of the brain certainly means that there are things that we'll never know mathematics that we'll never know because the mathematics is infinite and we can prove that the amount that the brain can ever know in its lifetime will be finite for example but but I I was more interested to try and identify actually a question that by its nature it doesn't matter how ingenious we are or whether there's another culture that is it's an essential part of the question almost is in regardless of who's who the we is that's trying to know it that what I really wanted was the that the question itself by its nature is unanswerable so for example in girdle's incompleteness theorem there's nothing about the human it's an the nature of this is not approvable but it's a true statement so so I think that but I certainly agree with you that a lot of what we know is through our senses for example that's how I mean this kind of discussion of Kenton's human there as well about that you know how much can we know it's only through our senses now what if there are things which we don't have the sensory equipment to actually interact with us how could we ever know anything about those so suppose you had an organism which has no ability to detect light well how could ever ever come up with a theory of electromagnetism so I think that is a real challenge you know how could we ever know about things which are sensory we don't have the sensory equipment or they may always be beyond our ability to know but it's something which we I think we have a chance if it interacts some way in some way with the things that we we can know I mean that's why things like the multiverse there may be many other universes but you know it still might impact it might have an effect on our universe so it's not unknowable for example so yeah we had a question here whoops sorry and we've got a young chap here and then I'll try and take some from the wings as well hello thank you that was brilliant talk ok with the Khans mechanics with the the you can never know the position and the momentum of the Vasco do you think that when we when we find a theory of everything that wouldn't you know it gravity with quantum mechanics do you think that then there will be like some sort of theory that will save right we can know this and we know exactly what is going to happen at a certain point or do you think there always be this wall where when we go beyond that small-scale there will say no we can't know I think this goes to the heart of something which I think is a problem with many of these questions which is almost a problem of language that we got very just used to talking about something having a position and or a momentum and that that we actually that's the attempt of these wave functions to give up on that that so I I think probably the solution will will be no we won't be that's a that's the old way of looking at it in and we must sort of give up on those words to actually be describing our universe and we need a different actually a kind of mathematical tools to be able to really describe an electron as as a probabilistic wave and and I think one of the things it may remove is this idea of the collapse of the wavefunction which is really doesn't kind of I mean that's the disconnect in this whole story and as you say we know that this isn't we haven't got to the there's sort of final theory because these two big theories the theory of the very big in the very theory they're very small are incompatible at the moment so you know there's an opportunity for a young scientist like yourself to come up with some way to resolve these and then that well may well answer some of the prom I think the quantum physics at the moment because it's been so powerful and so effective as Einstein said it's it it does amazing things that there's no need of them and there's no Drive when I was talking to quantum physicists there's no kind of feeling like what we need to change this theory it's working so well why do we need to in fact I out tell a story about a quantum physicist who started to think too much about quantum physics and then just had to leave the thing there that the kind of theory because the field because you just didn't think too much about it is there anyone who doubts that we will get to a theory of everything that's very easy you know why should why I mean it's a kind of weird some arrogance of science that there it there is this theory you know why should everything follow some people were really challenged that they you know maybe this belief in laws being controlling everything and then being compatible and actually we sort of know that we have different Sciences to describe different phenomena and they are sort of incompatible in some ways I mean if you're trying to describe the migration of a flock of birds well you could reduce it to schrödinger's wave equation but that's the wrong language actually you know the whole point of all of these different layers of science is that we produce different languages are better for exploring different things and I think one of the very interesting sort of themes that science is kind of trying to wrestle with is the idea of emergent phenomena things which grow out you know that aren't sort of there in the small but somehow our properties of when you put all of this together wetness of water or maybe consciousness questions are there any on the wings yes there's a lady up there coming freak again microphone thank you and I'd also love to take one take some questions in the gallery as well I'm sorry I can't see very bright lights very bright so this one up there will done will take and do you think Yelp to answer the question of where the constants of the universe come from because currently they don't spring from theory they're things that have to be measured and they kind of strangely fine-tune to fit with life being able to exist yeah that there's a really interesting discussion in the book about that because I think that is one of the big challenges you know it's amazing that you know Crick and Watson discovered DNA we know that that we have this kind of firm thing which creates life but we sort of understand where that came from is kind of you know you throw things randomly together over a long enough time we've got an explanation once that star so sort of eeveelution is kind of we feel we have a model of their the real challenge is where okay as you say the constants of nature seems so fine-tuned and the the resolution of this that so you could say well there's a somebody's fine-tuned and that's God so how do we counter that and I think the idea of the multiverse ISM is the best one we have for giving some explanation which is we have we've discovered that the universe inflated in an expansion in the very early stages of the Big Bang and to this idea inflation actually employs mathematically that this can bubble up in lots of different places giving rise to different universes in each of these bubbles and the idea is that in each of these these constants are just getting randomly assigned and so in some of them the sine Minh twenty eyes to life because the mass of an electron in that one is far too heavy although gravitational constant isn't right and of course we have have to have ended up in the one where it worked because of the anthropomorphic you know you we can only be in the one where where it worked and I think it's a similar explanation - well what about planet Earth I mean planet Earth nothing special about it's just randomly in this this Goldilocks spot and there are lots of unit planets than ions so we've sort of had to expand our kind of perspective on the universe to say well maybe the universe is the same there's just lots of universes and we happen to be in the Goldilocks universe I find that slightly and a satisfactory is an answer it's it's partly it's got an explanation of this inflation which is giving rise so it isn't coming out of any nowhere we've got an example of one universe so you know that's better than nothing but also just as a mathematician I would like there to be an explanation about why they have to be like that and it might be something like you know a bubble when you blow it it's a perfect sphere and there's a kind of low energy state so I'd love there ultimately be an explanation about why they had to be the way they are because of the kind of mathematical implications but we may have to just bite the bullet and have this kind of multiverse explanation for for witches you know I think is a is a reasonably good one did we have a question over here and then we'll go up to the gallery thank you unlikely to know because scientists don't want to know I mean I can give you an example yes Evan exact Alexander wrote a book called proof of heaven he's a neuroscientist you gada for meningitis was brain dead for two weeks but had very vivid memories of what he described as heaven but the end of his book he appealed for science to try and explain this hmm but he was coming across people who didn't want to well I think that's very interesting because um I I took part in an event at the serpentine gallery this weekend which I helped organize there we do these things called marathons and we take a a word and everyone comes in and we just talk about the word for the from different perspectives the word this year was miracles and miracles I think a very interesting example of what you're saying because on the one hand I mean miracles by their nature are things which contradicts current scientific theory and so you might think they're anathema to a scientist but on the other hand they are a kind of opportunity because that you want those moments when something unexpected happens when it's something you you can't explain so the Higgs boson was kind of exciting but we were expecting it so it was actually not as exciting as if we'd discovered something we weren't expecting there or or if it wasn't there it was kind of a so so I think that um and miracles are interesting examples that trouble is when you know it's just one thing and then you can't reproduce it and then it's it's sort of this you've got nothing to get your teeth into so I think that they're the sort of places where people get uneasy because they haven't got the tools to but I think also there are the places where there are opportunities so we shouldn't be closed to having a go at understand well why what what was it that I mean actually one of the I in the question chapter about what this is made out out of a course I interviewed Melissa Franklin who's a Harvard physics professor and she was very much involved in understanding the last quark and she talked about the sort of challenge of you know what what if suddenly you know the burning bush happens and so I have this revelation and then it sort of goes away and I don't know what do I do with that that's a very difficult thing to try and articulate to somebody and you know someone like Nash I guess you know had kind of these weird visions which he couldn't kind of integrate into other people was sort of our views of the universe but they were real to him as the things that were giving him his mathematical insights so that was that's the challenge and so so I'm seen yeah I think those those may be things that people are nervous about I wondered about the the nervous the nerves coming from perhaps that's where you invite the religious aspect of into science is there some nervousness among scientists about doing that well I think so but I I think that we it's very easy to become very dogmatic as a scientist and say this is the way it is and I think that I think the best mindset for a scientist is is somebody who's who's open to new possibilities so and crazy things but uh what you need to complement that with is the very self-critical questioning side so you need to be good cop bad cop warm perhaps I mean often in my mathematics I I work with a colleague who he's the good cop and I'm the bad cop he'd know this is possible this is probably no cuz of that and this and but another relationship I have I'm the good cop coming up with all the ideas and the other ones saying say no no it doesn't work like that and I think what often happens say with numerology or something is that in a numerology at its heart is what I do as a mathematician is to try and look for interesting weird patterns that people have missed but then I the numerologist sometimes forget to become critical and say you know okay but maybe this is just because a random as Sorum we had questions we didn't we yeah do you have a microphone yep okay so I was just quite intrigued by your linking musical instruments to subatomic particles just wondering what that was about oh yes yes exactly that was kind of the the interesting thing was so the object I took with me to look inside the the atom rather critically was the cello and the trumpet so I'm a trumpeter actually I got into math about same time as I started learning the trumpet and it's been very much part of my journey is its music as well as my science the engineering interesting thing about the trumpet is that you have discrete notes that you play so you put the valves down it changes the length and so it's a it's very discrete set of notes that you can make but a few years ago I was on radio 3 and I got to choose some pieces of music and they asked me questions and one of them was if you could learn new instrument what would it be and what would you want to play so I I play in an orchestra and I spend a lot of time counting bars rests and I'm always very envious of the cellist who seems to be playing all the time so so so I said the cello and I'd love to play the bark of sweets and so this kind of with sticking in the back of my mind and actually I decided I would take up the challenge again there's part of this sort of challenge I can only get to know how to play the cello at my age kind of can I learn a new instrument can I get to know new things learn new things so I started playing the cello one of the lovely things about the cello is that you can do a glissando you know you can go and it's so much fun and you can't do that on the trumpet and I use this as a kind of to tease out the question of is um the matter actually discrete made out of a little bit like an electron or proton and you put those together to build up matter or maybe I mean certainly the ancient Greeks thought that no matter was continuous in its nature that you could keep on infinitely dividing it that um that it had a sort of continuous endo kind of shape to it so so I use those two instruments as a kind of way and of course actually one of the ideas is that maybe this is quark sound here but there's another thing below that which is the idea of vibrating string so the cello as well was quite an interesting one to sort of the idea of yeah maybe the different harmonics on the the cello might be responsible for the particles that we're seeing I know you want to know the other self didn't you want to know the end of my joke oh yeah I'll tell you the end of the joke when we come to the end so let's have another question those sort of genes you asked for the end of the joke so as I said stro dinger is in the back of the car and so you little bit of science you need to know is this I dare Schrodinger's cat this kind of thought experiment that will have an electron can be two places the same time before you look at it there may be where it is could release a poisonous gas or not so if you put this whole thing in a box with a cat then if it is any kind of both places at the same time it means the cat is both dead and alive at the same time and until you actually observe it so so Schrodinger sitting in the back of the car and the policeman so what have you caught in your boot and he pulls the boot open is that you do you know what a dead cat in your boot and Schrodinger goes well it's dead now right okay we can have a couple more questions there's one there's a trap at the end of the row thank you great oh thank you very much do you have a distinction between something that doesn't exist and something we don't know I've been pondering the square root of minus 1 do you define that as not existing or something we don't know oh well I mean you see that's an interesting question about because of course for centuries we hit this thing the square root of minus 1 and we said well that thing doesn't exist there is no number which when you square it equals minus 1 and then there was this kind of amazing moment when people start to say well what if there was what if there was what do we imagine that thing so so you almost felt like an act of creation that people started to introduce a term to a number and they gave it a name they couldn't say where it was and the interesting thing was that this ending it didn't collapse mathematics it enriched mathematics and so you know I would say that the square root of minus 1 does exist but in what way does it exist it's kind of interesting it exists as something an idea in my mind but then maybe you know how many of these other things you've you traced back the square root of 2 what is the square root of 2 exist is it where's a measurement across a square but but actually quantum physics says that maybe you know you can't infinitely divide space and say the square root of 2 is an infinite decimal is is again just something of the mind and actually was kind of relevance to one of the conclusions that I come to in this book which is now how come mathematics is constantly right down there at the bottom of so many of these different theories quantum physics reduces to a lot of mathematical equations consciousness seems to be about a coefficient of the the network and in fact we have this paper by Vigna called the unreasonable effectiveness of mathematics and and you know why why is mathematics just always seem to be working and my feeling is that maybe you know if you're after an answer to where all of this stuff comes from you kind of need it a creator or something to create all of this stuff but as my kids always says well yes but who created the Creator you know but then you want something that is outside of time you want something which actually it doesn't need a creation and for me I believe that mathematics is outside of time that the the theorems of mathematics this the interrelations the structures the the the theorems are not something that was that needs creation and so for me that is the thing which then you know you blow fire into this thing and then you have the universe the theory the equations of quantum physics say that those mathematical equations give you an explanation why out of of maybe potentially genuinely nothing you can get something so you know some people often say well God is a mathematician my conclusion in a way is that well maybe you've got to reverse that maybe mathematics is the God which gave rise to everything here and that we are just a piece of physicalized mathematics we've got time to take one more question I think before we rise was there one in the gallery that I saw earlier there was I heard of yet a mistake a gallery there's one brilliant thank you right and your your book is also excellent so I'll recommend it from the audience thank you obviously it's finding them afterwards mad math centered and very brave of you to tackle all the other areas that just say on them consciousness why do we all need to say that the consciousness must be the same in people in fact we know about a consciousness precisely because it's different so for example some people are colorblind and react different to take colors autistic people bubble or black and so that's that's one point about consciousness and I think you're in your book about saying Daniel Dennett I think has got it right so that's something that we think is some big mystery at the moment which is no mystery at all listen an evolutionary development which is completely explicable in my view I think that yes III think you're right that's we we do know that people have different conscious experiences my wife is synesthetic so she has a sense of color when she looks at letters and numbers and I don't have that that's a very different so her brain is behaving in a very different way and actually I give some ideas maybe to try and explain that this idea of why different qualia kind of like encoded as a local high dimensional crystal and maybe some brains kind of actually encode that in shapes that are very similar so that's why they get this resonance between a letter and maybe a color or a shape and so and I think again Dennett's idea that maybe you know in years to come we will look back on this kind of big discussion about consciousness in the same way that we look back on the idea of what gives something life I mean that's quite an interesting question yeah why why do we consider these inanimate whilst you or all alive and what is that and the people talk about an lnb tal some some essence that was going to give life but now we've kind of just we assess that and we now just call life something which has these particular properties so it's almost just defined it by the conditions that it has it may be that consciousness will will go the same way that we will just have to because we cannot get inside somebody we will just have to call something conscious as it passes all of these tests but I think that will still be unsatisfactory because it doesn't get to the hard problem of consciousness the charmers challenge - yes but what is it about putting stuff together the thing you know what is the mechanism which gives rise to it having a sense of self but it may be that it will it will be a sort of sign talks about the challenges a language challenge and allowing and sort of language games and the believes that it's sort of you know that that that beetle we will never be able to really articulate why some of these peoples are different and others and why why would we ultimately need to I think he's loving it can you buy these markers outside on fine I took me a lot of time to find this it's it actually has to be a quite a high precision kit because you don't want the any friction sort of losing energy so actually had to retire one which she got a little bit he started not to be funny anymore there's a website in Germany that that makes kind of technical kit that I perform well before we go I have to say that the one thing I did realize my speaking up my sodden book it's there actually an order to have a sense of what we cannot know you have shown us an awful lot in terms of you know you knowing so much and sharing it with us and I can highly recommend the book it's a really really excellent read and so I would recommend that you let markers take you to the edge the books are outside and you can get them signed as well I think so this is a great time to say we have so enjoyed this lecture it's been absolutely brilliant you can you can hear that from the questions and the audience and I would love to thank the Royal Institution for hosting us both here in this beautiful lecture theatre Youth for coming but also most of all I would like to thank Marcus [Applause]

Channel: The Royal Institution

Views: 54,289

Rating: 4.8246574 out of 5

Keywords: Ri, Royal Institution, marcus du sautoy, limits of science, science, math, physics, Q&A

Id: jS4WfJeGP2s

Length: 32min 16sec (1936 seconds)

Published: Wed Jan 04 2017