Re: What is an observer moment?
Le 22-juin-05, à 20:35, George Levy a écrit : Bruno Marchal wrote: Le 21-juin-05, à 05:33, George Levy a écrit : Note that according to this definition the set of observer states may also encompass states with inconsistent histories as long as they are indistinguishable. The possibilities of observer moment being partially associated with (slightly) inconsistent histories resolves the question of how valid but erroneous observer moments can exist. For example I could make an arithmetical mistake such as 8*5 = 56 or I temporarily believe that Christopher Columbus discovered America in 1592. I agree. >An interesting thought is that a psychological first person can surf simultaneously through a large number of physical OMs With comp, we should say that the first person MUST surf simultaneously through an INFINITY of third person OMs. I agree there is and infinity of OM's that a psychological first person surfs through. But I would not say these OM's are "third person," because there is no third person to observe them. A psychological "third person" would be too spread out among OM's to observe any one in particular. I agree. (I would not use the term "physical" at all, because at this stage it is not defined. But with the negation of comp + assumption of slightly incorrect QM what you say seems to me plausible.) Are you saying that COMP does not admit (slightly) inconsistent histories? No. Quite the contrary, comp does admit inconsistent histories. But for reason of methodological simplicity, I limit my "interview of lobian machines" only on the consistent machines, for which comp makes necessary the consistency of inconsistent histories. With comp, a consistent machine is in the state of being *possibly* inconsistent. I know you read the Smullyan's FU, and I'm afraid it is not enough. I mean it is a non trivial consequence of the incompleteness phenomenon that a consistent machine is automatically consistently inconsistent, and this in the frame of the brave and simplest logic (classical logic). I am not sure if I agree with this. I can be a psychological first person and still say "yes doctor" to a computer transplant into my brain. Not only I agree, but the point is that with comp it is necessarily so. Bruno http://iridia.ulb.ac.be/~marchal/
Re: What is an observer moment?
Bruno Marchal wrote: Le 21-juin-05, à 05:33, George Levy a écrit : Note that according to this definition the set of observer states may also encompass states with inconsistent histories as long as they are indistinguishable. The possibilities of observer moment being partially associated with (slightly) inconsistent histories resolves the question of how valid but erroneous observer moments can exist. For example I could make an arithmetical mistake such as 8*5 = 56 or I temporarily believe that Christopher Columbus discovered America in 1592. >An interesting thought is that a psychological first person can surf simultaneously through a large number of physical OMs With comp, we should say that the first person MUST surf simultaneously through an INFINITY of third person OMs. I agree there is and infinity of OM's that a psychological first person surfs through. But I would not say these OM's are "third person," because there is no third person to observe them. A psychological "third person" would be too spread out among OM's to observe any one in particular. (I would not use the term "physical" at all, because at this stage it is not defined. But with the negation of comp + assumption of slightly incorrect QM what you say seems to me plausible.) Are you saying that COMP does not admit (slightly) inconsistent histories? I am not sure if I agree with this. I can be a psychological first person and still say "yes doctor" to a computer transplant into my brain. George Levy
Re: What is an observer moment?
Le 21-juin-05, à 05:33, George Levy a écrit : An interesting thought is that a psychological first person can surf simultaneously through a large number of physical OMs With comp, we should say that the first person MUST surf simultaneously through an INFINITY of third person OMs. (I would not use the term "physical" at all, because at this stage it is not defined. But with the negation of comp + assumption of slightly incorrect QM what you say seems to me plausible.) Bruno http://iridia.ulb.ac.be/~marchal/
RE: What is an observer moment?
George Levy wrote: A lot of confusion seems to arise about what an observer-moment is. I would like to propose the following distinction between a physical observer-moment and a psychological observer moment, along the same lines that I discussed under the thread copying. A physical observer moment is defined by an observer physical quantum state accompanied by the set of all consistent histories justifying this state. It requires and includes a causal light cone to be drawn from that point extending toward the past (and expending toward the future). Hence a given physical OM includes several pasts and multiple futures. Because of the QM Non-cloning theorem two identical physical OMs cannot be copied. In addition because two identical OMs must comprise identical causal cones they must be one and the same in the same visible universe. Of course copies may exist beyond the causal cone or in other universes. Since a physical OM cannot be copied, the measure of a physical OM cannot be increased within the causal cone. A psychological observer moment is defined by a set of observer states which cannot be distinguished from each other by a subjective test performed by the observer. This definition is significantly looser than the one for physical observer-moment. Thus a single psychological observer moment can encompass a large number of physical observer moments. Note that according to this definition the set of observer states may also encompass states with inconsistent histories as long as they are indistinguishable. (I am not sure if I should enforce "consistent histories" on psychological OMs by replacing "observer states" by "physical observer moments") The consideration of what is the measure of a psychological observer moment forces us to differentiate between physical first person and psychological first person. From a physical first person point of view, a psychological OM can include multiple physical OMs and therefore can have a high or low measure. However, from a psychological first person point of view, since all the physical OMs are indistinguishable, the measure cannot be increased by increasing the number of physical OMs. *** What sort of subjective test are we talking about re. distinguishable psychological observer moments? Something like "do I remember the lady in the red dress?". We can't really compare two psychological observer moments side-by-side, unfortunately. How do we account for "identity" among all this. Am I a physical first person, or a psychological first person? Or both (context dependant)? I (both my physical and psychological first persons) am still confused :). Jonathan Colvin
