Nick Prince wrote:
Hi Brent Perhaps Bruno could give some clarification here. Just prior to his conclusion on the sane paper I quoted from was this:"So if we keep comp at this stage, we are forced to relate the inner experience only to the type of computation involved. The reason is that only those types are univocally related to all their possible counterfactuals. This entails that, from a first person point of view, not only the physical cannot be distinguished from the virtual, but the virtual can no more be distinguished from the arithmetical. Now DU is emulated platonistically by the verifiable propositions of arithmetic. They are equivalent to sentences of the form ‘‘it exists n such that P(n)’’ with P(n) decidable. Their truth entails their provability, and they are known under the name of Sigma1 sentence. If comp is correct, the appearance of physics must be recovered from some point of views emerging from those propositions.
Why only the atomic sentences? Why not all true sentences? How is "appearance" recovered?
But what gives the probability measure? Is it just the relative frequency of occurrence of the atomic sentences in the UD output up to a given step?Indeed, taking into account the seven steps once more, we arrive at the conclusion that the physical atomic (in the Boolean logician sense) invariant proposition must be given by a probability measure on those propositions.
A physical certainty must be true in all maximal extensions, true in at least one maximal extension (we will see later why the second condition does not follow from the first) and accessible by the UD, that is arithmetically verifiable. Figure 8 illustrates our main conclusion, where the number 1 is put for the so called Sigma1 sentences of arithmetic." It sounds as if Bruno thinks that the computations of the UD invoke our inner experiences and also our understanding of physics. Both come from arithmetical platonicism ( because thats what the UD is all about). So the pictures in the "film" are stiched together by the arithmetical (computation necessity) rather than the laws of of physics... Hmm not what I thought and said earlier!! So according to Bruno the laws of physics come from something intrinsic in the computation? Not quite sure how. I just can't figure out any more at the moment and hope Bruno will give me a hint here. Enjoying the dialogue! Nick On Jan 5, 10:44 pm, Brent Meeker <meeke...@dslextreme.com> wrote:Nick Prince wrote:OOps sorry I sent an empty post by accident.I agree with you here. But I am new to this field so I am uncertain about so many things. However, I don't understand why it is that a UD would know how to generate these law like sequences of states. It may well generate all possible programs that generate all possible universes (with different values for the physical constants say - maybe even different laws) but I wonder why our conciousness defines itself by "selecting" only those "consistent" extension among all the states available that obey a certain set of laws of physics.I thought that a TOE should explain the laws of physics and Bruno states in his SANE paper" Conclusion: Physics is given by a measure on the consistent computational histories, or maximal consistent extensions as seen from some first person point of view.But consistent in what sense? We can't say "consistent with the laws of physics" because that's what we're trying to explain.Laws of physics, in particular, should be inferable from the true verifiable atomic sentences . Those are the verifiable arithmetical sentences.I understand true arithmetical sentences, but I'm not sure what 'verifiable' means? Does it mean computable, or provable? What's an atomic sentence? Is it just a finite statement, like "17 is prime"; so it excludes infinite statements like Goldbach's conjecture? BrentThey should be true everywhere (= in all comp histories), true somewhere (= true in at least one comp history), and inferred from the DU-accessible atomic states". It feels a bit lie a chicken and egg situation - do we pick out the laws or do they pick us?. But I am still working my way through this and and loads of other stuff, so I don't understand it yet.BestNickOn Jan 5, 6:59 pm, Brent Meeker <meeke...@dslextreme.com> wrote:Nick Prince wrote:Is this because you think of your stream of consciousness as somehow like a reel of film? All the individual pictures could be cut from the reel and laid out any which way but the implicit order is always there. I can understand this because all the spatio temporal relationships for the actors in the film remain "normal" i.e obey the laws of physics.But there's the rub. Why the laws of physics? That's what somehow needs to be explained. Is there something about the UD that necessarily generates law like sequences of states with high probability? Doesn't it generate just those laws we seem to find - that would be a great discovery. Or does it generate all possible non-self-contradictory multiverses - in which case nothing has been explained.Deutsch argues similarly in the Fabric of reality. In my work I often come across the idea of a foliation of hypersurfaces which is really a set of 3D pictures "stuck together and stacked in the direction of the time coordinate of the world at a given instant of time.But that's starting with the physics given, so the hypersurfaces and their relation is already defined.BrentIn MW interpretation though I guess that the stacking is less certain as in the block universe idea but that's another issue. Is this analogy similar to how you feel the "obvious" experience of time being normal?BestNick- Hide quoted text -- Show quoted text -- Hide quoted text -- Show quoted text -- Hide quoted text - - Show quoted text -
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