On 8 May 2017 8:21 a.m., "Bruce Kellett" <[email protected]> wrote:
On 8/05/2017 4:53 pm, David Nyman wrote: > Both Hoyle's pigeon holes and Barbour's time capsules assume that there is > a coherent underlying physics with regular exceptionless laws. Until you > have something like that, you cannot define consistent continuations. > > But I'm afraid that's implied by assumption unless one takes the view that > the evolution of physical states is fundamentally incomputable, > But I thought that that was what Bruno claimed. If one assumes physics in one's derivation, then the circularity is vicious. Oh dear no, that's not right at all. What is uncomputable is any extrinsically conceived *extraction* of physics from the computational Babel consequent on the theory. There is no possible search function for this. That extraction then is necessarily a complex consequence of observer selection. Post such extraction, the evolution of physical states is then by assumption finitely computable, modulo the FPI, else computationalism must fail as a theory of mind or of physics. At this point the objective situation, mutatis mutandis, is essentially equivalent to Everett's relative state assumptions. The other point on which I must take you to task is again the question of circularity. It's not the job of computationalism's toy model to explicate every detail of the extraction of physics, although it's already the case that it *predicts* the multiple continuations implicit in the wavefunction, which is more than can be said for QM itself which merely retrodicts them (again modulo the FPI). Given the conjunction of the assumption of computationalism and our observation of the physical environment described by QM, all the theory has to show at this stage is that it is not incompatible with these data (as it would be if, say, the evolution of the wavefunction itself were shown to be uncomputable). It should further explicate some reasonably convincing justification for why just such a physics might be expected to underpin the effective environment we observe. But the *facts* of our observation of such a physics are not at issue. There is no relevant question of circularity to deal with here. As to the so called Occam catastrophe, as exemplified in your Boltzmann brain scenario, potential resolution necessarily can be understood under computationalism only from a first person perspective, as I previously suggested to you. We need to justify, in terms of a subjective measure, why we should indeed expect the physics we observe to emerge as the predominating computational mechanism underlying our normally intelligible perceptions. To do this we only need to show that "last Tuesday" computational snippets can only reinforce, and magical or unintelligible ones cannot interfere, with "normally intelligible" and complexly connected continuations. A way to grasp this intuitively is in terms of something like Hoyle's "amnesic multiple personality" heuristic which, though as you say it was originally based on the assumption of physics, IMO illustrates the relevant considerations equally intuitively on computational assumptions. In any case, the analogy of a multitasking OS that I also mentioned suffices equally well in this regard. >From this perspective, no amount of white noise in continuations of "Boltzmann" computations could make a substantive subjective difference. The reason being that the consequence is overwhelmingly likely to be a total subjective unintelligibility which will plausibly tend to be utterly swamped, in the struggle of forgetting and remembering, by "normally intelligible" continuations. The FPI is, obviously, the relevant consideration in this regard. This is what I meant when I said that an absence of evidence for this sort of pathology or unintelligibility is not evidence of its absence. It suffices that these out of phase components of experience be swamped in the battle for what one might term personal subjective emergence. They just typically get forgotten far more frequently than they get remembered by Hoyle's multiply solipsistic agent. Hence what we may think of as pathological scenarios would be expected to be very poor and haphazard candidates in the ongoing struggle for apparently persistent, pervasive and lawful subjective emergence. What would emerge with these characteristics would then be consistently remembered histories underpinned by a robust and reiterative physical mechanism whose highly selective observation by us would then be the final evidence of its predomination in this epic personal struggle. I gave you an illustration a few days ago (on which you didn't comment) of what one might term the "psycho-theological" aspect of computationalism. I said that consciousness or first person subjectivity was really a pointless cherry on the cake of physics whose mechanism must be assumed to proceed without any a priori need of such a baroque supernumerary assumption. Indeed it can only be an a posteriori datum tacked on to the physical scheme of things. Computationalism, by contrast, can only be understood in the final analysis as a synthesis of all possible subjective personal histories. "Point of view" is then just what prevents them from all happening at once. Thus physics, under the same assumptions, can in turn be understood finally as the successful computational generator underlying the "dreams of the machines". David Bruce -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
