Sean Carroll - Physics of Consciousness

Transcript

Sean Consciousness has been one of my focuses of Life uh my doctors in Neuroscience because I wanted to try to understand conscious of course one had very little to do with the other at that point uh but I've continued to to focus on it as as perhaps the the uh key to un to really understand reality now you may disagree with that I know you're a radical physicalist so how do you deal with Consciousness I think that Consciousness is a way of talking about the physical world just like many other ways of talking is an one of these emergent phenomena that we find is a useful way of packaging reality so we say that someone is conscious of something that corresponds to certain physical actions in in the real world I don't think that there is any special about mental properties I don't think there's any special mental realm of existence I think it's all the physical world in all the manifold ways we have of describing it okay uh give me another example of an emergent phenomenon well the classic example of an emergent phenomenon is the fluid description of the air around us the fact that even though it's made of discrete particles atoms and molecules we talk about it as a Continuum with a pressure and a temperature and stuff like that it's a it's a macroscopic coarse grain view great example the wetness of water would be something similar okay now uh I would believe uh that Consciousness is a quality atively different from that because there is a um there is something that is like to have the feelings that I'm seeing you call it an internal movie whatever you want to call it that the phenomenology of of of this is is a a a a a radical difference from the getting the wetness of water from Individual molecules or the fluidity of air right and you must disagree with that I do disagree with that uh I think there is this there's an irreducibility but it's not in the reality it's in how people talk to each other about it I I and I there's there's something that but you see it you live it you feel it course that's right and I can describe it in physical terms perfectly well when when you say like I now have experienced the uh redness of red I think that that is a set of words that can be mapped on in a very direct way to certain physical things happening in my brain oh nobody doubts that there there are people who doubt that but yes many people do not doubt that and I think that's all there is at least my FR nobody doubts that you know when you talk about the existence of a cat you know this is this is a category that is not to be found in the fundamental laws of physics a cat a game of basketball is not to be found these are useful categories for describing the world I think that Consciousness self-awareness experience inner subjectivity very useful categories for describing the world now but you know some physicists see Consciousness as sitting below the the wave function not just part of the wave but actually sitting below it as the most fundamental thing some physicists deny global warming I mean I think it's some physicists is not a very good beginning to almost any s okay all I accept that um so but but but with with Consciousness your uh one philosopher has said that Consciousness uh is an output of the brain like urine is the output of the kidneys is that something you would subscribe to it's uh no I don't not sure I would use that exact metaphor I mean again I think it's a very very useful construct at a higher level of description right I can't imagine doing without Consciousness as a way of talking about the world I know what it means when people say I'm conscious of this I know what it's like to be that these these are real ways of describing the underlying when you're saying I'm conscious of that's sort of a a a an English locution that means I'm aware of something but you could you could almost be conscious or aware of something in a in in a in a in a mechanical or zombie like way in in terms of Behavioral reaction but I'm talking about this this the phenomena that we all feel seems so radically different from anything that you see in the brain I mean I dealt with that you do with the probing of electrod and electrochemistry and uh and genetic Expressions do you believe that the the the phenomen phenomenology of what we see is in an identical Theory sense two descriptions like uh the morning star and the evening star is is the same yes that's right Venus is the same thing I'm just call it by different reason because I didn't know that they were the same absolutely and I think that actually to me zombies the idea of the philosophical zombie something that acts in exactly the same way as a conscious creature but just lacks the Consciousness lacks that inner subjective experience is a great argument for my position in the sense that it's very hard to really take self-consistently this idea a philosophical zombie because if you met a zombie you ask them what are you experiencing right now they would tell you exactly the same thing that a regular person would say right and and you say well at least I know I'm not a zombie do you really know that of course you're telling yourself you're not a zombie you're experienced things but so with a zombie a zombie would say they're not a zombie I think that there's really no way of boiling that thought experiment down to a consistent holding of the idea there could be something that physically acts exactly like me yet lacks the the zombie would say that I'm not a zombie and describe the inner feelings but would still be a zombie that that that is the that is the proposal and I I'm just pointing out how how silly it begins to sound because they would be sincere look I think really think they're experiencing it they would really say that Li it would be it's a sort of a behavioral reaction it'll it's sort of an input output that's right and the difference between me and someone who thinks that there is something phenomenologically different about Consciousness is that that is all there is so an implication of your view I I think is that you have to be 100% sure that at some uh time in the future with future Technologies some people would say 20 or 100 years some people may say a thousand years you would be able to upload your individual firstperson Consciousness to uh another medium whether it's non-biological or another person you you would have to be 100% sure of that well I'm not 100% sure anything in the world I'm not 100% sure that the univers no given your presupposition as a radical physicalist to Consciousness that's what that's the GI yeah I see no I think the way I'm happy to say it is I see nothing special about an organic human being that could not be duplicated to arbitr or if if there were something then you could just duplicate it in an organic you could create a human being and we all know there thought experiments so we we do believe most people believe that I could take out one neuron from my brain all right an elect and then I still just as conscious what happens when I take out two and to me that's not even an issue like yeah sure just as conscious all the way down okay so you go all the way down and you prund billion and one neurons and and you're and you will and since we in the thought experiment perfectly reproduced every neuron every connection every reaction Etc that you will have noticed no difference during the the whole process okay so let me take that one step further that every time that I put that neuron in we both both agreed it was a perfect replication I made two of them and I put one over here yeah and then I made another and when I got to the 100 billion and you you haven't felt any difference right I H I have 100 billion of another another one another uh Sean right here that's right and so so now what where's the Consciousness where's the first person two conscious things there's two conscious things but that's not your Consciousness here no well that no if I'm the one here that's another one what do you mean so then it's just like the branching of the wave function of the universe there's now two copies of me that go their own ways but but but you have no awareness of this one that one has its own awareness I have my own awareness but and you have no it's not like you have a shared Consciousness no certainly not right you don't you don't have a fractional Consciousness so so the this this is going into so this is like your twin yeah exactly so that's not you no that's a that's a copy two copies okay so then but I just made a per this is 100 % the same as what you have right but this is a philosophical this a mological question uh this is the ship ofus right no I don't think so I don't think you're the ship if I didn't have the second one you'd be the ship of thesis right but the point is that if you just if if you want to sort of really get down to what the identity is at every moment of time there's a different thing right there's a different configuration of stuff there's this configuration of stuff at this moment of time this configuration of stuff at this moment of time if you're reifying the idea that there is some unified flow of conscious experience through time I'm going to deny that yeah I I'm not I'm not at that point I'm just I'm just at the skeptical position of of of of following what follows from your analysis that Consciousness no trouble being these two separate conscious but but if that's not if that second one is not you what is the difference because at at at T Unice no at t0 from a physical point of view we would both agree that are exactly the same right they they're just in two different places that's right yes okay and so it's the question which one is you is just meaningless there's just two of them and it becomes meaningful if if if we if we take the original which was you with all your neurons replaced and um and and burn it well there's two people there's two conscious creatures if you want to start burning them then you know by ordinary moral standards that'll be a bad thing to do uh yeah but just like having a duplicator machine yeah so you right you have a duplicator machine but but the you that you that had didn't experienc any difference during the the uh the the switching process with neurons you haven't experienced anything that and you may not even be aware of this other thing that I've created on the side because I didn't tell you um and then if you're destroyed your individual firstperson experience will go out of existence because you have this other one here yeah right is that right yeah I mean they will have identical experiences but they will have identical memories experiences but they won't have your first person you won't if if no they'll have everything that I had by construction right but there would be two of them and there's two of them you destroy one then there's one of them right and they will go their own future ways right but but in terms of your internal sense of this individ if you didn't know that this existed and and you were made to not exist burning or something else you would go out of existence yes okay so so if that's true then you then that indivi personal one first person experience cannot be uploaded no that has a per first person experience that is the same as mine but it's like an identical twin in the same as it's not it's much better than identical twin it's really identical yes that's right but it it doesn't have your first person because I think you are attaching some metaphysical continuity to this experience some some uniqueness to it at every moment of time there is a set of things that are having conscious experiences you describe an elaborate way to take one of those and make two of them and both of them can persist or not persist talk to each other never talk like all those are possible and none of that gives in my mind any special weirdness to the physicality of Consciousness we're not we're not at that stage yet I'm just saying that it you you if we if you are unable then to be uploaded with your first person experience because you can be uploaded but you would be the same as this other entity over here which would be a SE a very close identical twin with all your memories but it wouldn't have your first person experience and so I don't think you can say these statements you're saying without using the word you and I think that's the problem there is a person here who has conscious experiences you're creating a way of making an identical twin of them there are now two people with experiences they are both going to go on and and do whatever they do uh is there any objection to that no I mean I think that the is there a difference let me ask it this way is there a difference between uploading you and now you're uploaded and I'm not sure whether we destroy the original we don't and having this duplicate here it sounds like the same thing yeah it's the same thing right it's the same thing so um if if you would be uploaded uh do you feel would that give you a virtual immort ality when I'm using the word you in terms of your first person experience or would you feel like it's a very close relative that will go on like my child but it's it's a it's it's more than a child I I I I really think that you're attaching some uh magical reality to youness or meanness like me now is not the same as me a day from now right so have the internal coherence you have the internal coherence they're related they're certainly very related just as I would be to this uploaded thing but there's two conscious the uploaded one and then there's the physical one so your argument is is that uh Sean Carol now and sha Sean Caroll tomorrow morning is the same relationship as Shan Caroll here and Sean Carol that would be uploaded it's very similar obviously it's not exactly identical because of the terms of the thought experiment but it's essentially the same yes okay so that that would um that would mean that in your mind Consciousness is uh is certainly not an important fact in the universe it's a a contingent accident of what what happened here at some point depends what you mean by important it's very important to me it's as important as cats and baseballs and so forth yeah it's a very useful way to think about what happens in our world