On 11 Jul 2011, at 19:56, meekerdb wrote:

On 7/10/2011 8:16 AM, Bruno Marchal wrote:You confuse perhaps with Schmidhuber's position, or some digitalphysicist (DP). But as I have explained many times here that thisposition does not work. Computationalism or digital mechanism (DM)is the idea that "I" am a machine, and by the first personindeterminacy, and the way the laws of physics have to emerge fromcomputations, the physical universe (nor the fundamental reality)cannot be described entirely by a computation. On the contrary itis a sum on an infinity of computations.If the universe is a computation, then "I" am computable, but thenit cannot be a computation (by what I say above, it is notobvious). So with comp, or without comp, the physical universe isnot a computation. With comp, the laws of nature are notcomputable, or have strong non computable components.DM -> ~DP DP -> DM, So DP -> ~DP, so ~DP. BrunoThis confuses me. When you say the universe is not computable, youmean it is not the process of computing a function. But you thinkit is generated by a UD. Right? In other words, you are sayingwhat a UD does is *not* a computation.

`I think you are forgetting to take into account the first person`

`indeterminacy. Your probable next first person state in indeterminate,`

`and the domain of indetermination is all the third person states`

`equivalent (in the third person doctor sense) with the state of your`

`current body (at the right level or below) generated infinitely often`

`by the UD. The physical laws have to be retrieved from that`

`indeterminacy on that domain, and there is no reason why your`

`statistical experience or physical reality is computable.`

`The UD does (an infinite) computation, but the universe results from`

`an internal and relative statistics on all computations.`

`It remains possible that somehow a computation wins the game, but if`

`that is the case that has to be justify from the statistics on all the`

`computation, and strictly speaking this is rather unplausible.`

`Instead of the UD, take the simpler case of the iterated WM self-`

`duplication. Let us fix the iteration to 1000. In this case, you can`

`see easily that what you can expect is not computable at all. All`

`2^1000 histories will be generated, and the computable are rare.`

`The UD makes dummy similar iteration with all states, so you can guess`

`that physics arise from a subtle mixture of computability and`

`randomness. I think that Bennett depth plays also a role, the self-`

`referential constraints play a role. But it predicts that some`

`randomness is at play in the stabilization/normalisation of the deep`

`computational histories.`

`You don't need step 8 to understand this. Just imagine the "physical`

`universe" big enough to run a UD. In one instant your futures is`

`determined by an infinity of computations. This shows already that`

`physicists use implicitly an induction principle, by assuming the`

`inexistence of other instantiations of couple <you, the observed`

`electron> other that the one under their consideration. But the UD`

`guarantied (unlike Boltzmann brain) an infinity of them.`

Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.