On 27 Feb 2012, at 21:38, meekerdb wrote:

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On 2/27/2012 11:56 AM, Bruno Marchal wrote:You can make matter behave in any way relatively to virtual realitythat you are building, but the 3-creature, relative to you, will beable to deduce from their observation that they are in a simulatedreality, by comparing what they can measure with what canrelatively emerge from *all* computations.That sounds good but its implementation is problematic. What canrelatively emerge from all computations is not something we can knowif your theory if correct.

Why?

`On the contrary we can know that by interviewing simple machine that`

`we can prove to be correct, like PA.`

And if what can emerge is essentially anything (which I think islikely)

`The propositional logic of the observable have already been derived.`

`It is not *anything* at all. It is a precise arithmetical orthologic,`

`or minimal quantum logic.`

`Let me give you an example how to test comp in practice. You can take`

`a quantum-empirical tautology, like a Bell inequality:`

A & B => (A & C) V (B & ~C)

`which is true in the Boolean algebra, but not necessarily satisfied in`

`"physical" comp, as it is not in the natural quantum ortholattice of`

`quantum propositions.`

`You need to represent it in modal terms, by using the quantization`

`translation of Goldblatt, this gives:`

[]<>A & []<>B => []<>([]<>A & []<>B) V ([]<>B & []<>(~[]<>C)

`This should be seen as a formula in the material hypostases, so you`

`need to translate this in G*, this will give a very long formula,`

`because just []<>A becomes []([]A v <>A) & <>([]A v <>A), so we get`

`[]([]A v <>A) & <>([]A v <>A) & []([]B v <>B) & <>([]B v <>B) => etc`

`(very long due to the double nesting of the quantizations []<>#).`

`This gives a long formula that you can test in G*, more exactly in G*1`

`(G + p->[]p, need to makes the machine assuming comp, and restricting`

`herself on the UD accessible states).`

`The whole formula is already to complex for my 1990 modal theorem`

`prover, unfortunately. My translation above is also not completely`

`correct because the deduction "=>" should be replaced by "->", which`

`itself is rather long to translate. But my point was only illustrative.`

`If G* does not find a counter-example to the last, corrected, formula,`

`it means that the comp-physics does not violate the simple Bell`

`inequality. If G* finds a counter-example, then you can read it as a`

`description of a possible experience in the comp physics which`

`violates that Bell's inequality. G* is complete, and you can ask it`

`all experiences/counter-examples to that Bell inequality.`

`In 1990 I predicted that comp (+ classical knowledge theory) would be`

`refuted before 2000. This has not yet happened, though.`

`From a paper of Rawling and Selesnick there are evidences that comp`

`might define a canonical quantum computer in the background physics of`

`all universal machine. That is some comp-physics tautologies seems to`

`be rich enough to implement universal quantum gate.`

`Anyway, by the UDA reasoning you can know that we should get the whole`

`physics in the corresponding, non necessarily propositional, logics,`

`so it is hard to imagine a more "refutable" theory than comp, once we`

`accept Theaetetus or the classical theory of knowledge (verified`

`notably by the Theaetetus idea when applied on the notion of comp`

`belief).`

Bruno

then no observation can falsify the theory. Brent --You received this message because you are subscribed to the GoogleGroups "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.

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.