Bruno, I do not find Deutsch's introduction of a rational decision maker convincing e.g.: http://arxiv.org/ftp/quant-ph/papers/9906/9906015.pdf nor Wallaces elaboration on that theme e.g.: http://arxiv.org/pdf/0906.2718v1.pdf.
My belief is that a rational decision maker, somewhat like a god, would following Leibniz, always chose the best quantum state in any interaction to become physical in a single universe. In fact that seems to be exactly what Wallaces rational decision maker does. I think Deutsch has snookered us all. Richard On Mon, Oct 29, 2012 at 11:28 AM, Bruno Marchal <[email protected]> wrote: > Hi Richard, > > On 28 Oct 2012, at 21:01, Richard Ruquist wrote: > >> Bruno, But it seems that the Gleason Theorem assigns probabilities to >> the different universes in the multiverse that are not there in >> Everett's MWI in the first place. Richard > > > ? > I don't see that, nor why you say so. can you elaborate? Gleason theorem > just makes unique the usual Born rule, and justify a literal reading of the > quantum amplitude as relative (infinite) proportions. > It is quite similar to the Deutsch Hayden justification, in decision > theoretical terms, of such amplitude reading, in the Heisenberg picture. > > Bruno > > > > >> >> On Sat, Oct 27, 2012 at 9:46 AM, Bruno Marchal <[email protected]> wrote: >>> >>> >>> On 26 Oct 2012, at 15:52, Richard Ruquist wrote: >>> >>>> Well Bruno, >>>> >>>> If the "measure problem" (which I take to be the assignment of >>>> probabilities) is intrinsic to Everett's MWI, does that not amount to >>>> negating it? >>> >>> >>> >>> Why? I think that it is beautifully solved by Gleason theorem, for the >>> Hilbert space of dim bigger or equal to 3. >>> >>> >>> >>>> I did not suggest that it negated comp, which is what you >>>> responded to. >>> >>> >>> >>> I think comp will confirms Everett QM, and this would make our sharable >>> human or animal substitution level very plausibly at the Heisenberg >>> uncertainty level, this for surviving even a long run, without detecting >>> any >>> difference. >>> >>> In that case, the Gleason solution will be the solution for comp. For >>> this >>> the X and Z logics (alreeady extracted) must conforms to some desiderata, >>> already expressed by von Neumann, for a quantum logic, and which is that >>> mainly it defines the searched measure. >>> >>> I m not sure I can understand string theory or any fundamental QM without >>> Everett. >>> >>> I agree that the idea that we are multiplied by infinities at each >>> instant >>> is not attractive, but science is not wishful thinking, and besides, I >>> don't >>> take any theory too much seriously (we don't know). I also know that >>> different theories can happen to be equivalent. >>> >>> Of course, to be sure, comp has also many attractive features, mainly its >>> conceptual simplicity and naturalness. It really explains almost why >>> there >>> is something instead of nothing, as it assumes only 0 and the successor >>> and >>> the very simple laws, and explain from that how that very explanation >>> emerges in some collection of stable numbers' dream. >>> >>> Bruno >>> >>> >>> >>> >>> >>> >>>> Richard >>>> >>>> On Fri, Oct 26, 2012 at 9:35 AM, Bruno Marchal <[email protected]> >>>> wrote: >>>>> >>>>> >>>>> Richard, >>>>> >>>>> On 25 Oct 2012, at 18:42, Richard Ruquist wrote: >>>>> >>>>>> Bruno, >>>>>> >>>>>> Doesn't the Gleason Theorem negate MWI by assigning probabilities? >>>>>> Richard >>>>> >>>>> >>>>> >>>>> >>>>> On the contrary. Gleason theorem solves the "measure problem" intrinsic >>>>> in >>>>> the Everett MWI, it makes the probabilities into comp (or weakening) >>>>> first >>>>> person indeterminacies. >>>>> >>>>> Unfortunately, comp necessitates a version of Gleason theorem for all >>>>> comp >>>>> states, not just the quantum one, as the quantum law must be derived >>>>> from >>>>> the 1p indeterminacies, occurring in arithmetic. >>>>> >>>>> The advantage is that comp provides the theory of both quanta and >>>>> qualia >>>>> (and a whole theology actually). >>>>> Unfortunately, it is not yet clear if those quanta behave in a >>>>> sufficiently >>>>> quantum mechanical way, like making possible quantum computers, >>>>> hydrogen, >>>>> strings may be, etc. >>>>> >>>>> Bruno >>>>> >>>>> >>>>> >>>>> >>>>>> >>>>>> On Thu, Oct 25, 2012 at 9:38 AM, Bruno Marchal <[email protected]> >>>>>> wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 24 Oct 2012, at 19:53, meekerdb wrote: >>>>>>> >>>>>>> On 10/24/2012 4:31 AM, Bruno Marchal wrote: >>>>>>> >>>>>>> >>>>>>> On 23 Oct 2012, at 14:50, Roger Clough wrote: >>>>>>> >>>>>>> Hi meekerdb >>>>>>> >>>>>>> There are a number of theories to explain the collapse of the quantum >>>>>>> wave >>>>>>> function >>>>>>> (see below). >>>>>>> >>>>>>> 1) In subjective theories, the collapse is attributed >>>>>>> to consciousness (presumably of the intent or decision to make >>>>>>> a measurement). >>>>>>> >>>>>>> >>>>>>> This leads to ... solipsism. See the work of Abner Shimony. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> 2) In objective or decoherence theories, some physical >>>>>>> event (such as using a probe to make a measurement) >>>>>>> in itself causes decoherence of the wave function. To me, >>>>>>> this is the simplest and most sensible answer (Occam's Razor). >>>>>>> >>>>>>> >>>>>>> This is inconsistent with quantum mechanics. It forces some devices >>>>>>> into >>>>>>> NOT >>>>>>> obeying QM. >>>>>>> >>>>>>> >>>>>>> No, it's only inconsistent with a reified interpretation of the wf. >>>>>>> It's >>>>>>> perfectly consistent with an instrumentalist interpretation. >>>>>>> Decoherence >>>>>>> is >>>>>>> a prediction of QM in any interpretation. It's the einselection >>>>>>> that's >>>>>>> a >>>>>>> problem. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> But instrumentalism is just an abandon of searching knowledge. There >>>>>>> is >>>>>>> no >>>>>>> more what, only how. >>>>>>> An instrumentalist will just not try to answer the question of >>>>>>> betting >>>>>>> if >>>>>>> there is 0, 1, 2, ... omega, ... universes. >>>>>>> >>>>>>> And the einselection is not a problem at all, in QM + comp. It is >>>>>>> implied. >>>>>>> And, imo, the QM corresponding measure problem is solved by Gleason >>>>>>> theorem >>>>>>> (basically). >>>>>>> >>>>>>> And then, keeping that same 'everything' spirit, the whole QM is >>>>>>> explained >>>>>>> by comp. We have just to find the equivalent of "Gleason theorem" for >>>>>>> the >>>>>>> "material hypostases". >>>>>>> >>>>>>> Bruno >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> 3) There is also the many-worlds interpretation, in which collapse >>>>>>> of the wave is avoided by creating an entire universe. >>>>>>> This sounds like overkill to me. >>>>>>> >>>>>>> >>>>>>> This is just the result of applying QM to the couple "observer + >>>>>>> observed". >>>>>>> It is the literal reading of QM. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> So I vote for decoherence of the wave by a probe. >>>>>>> >>>>>>> >>>>>>> You have to abandon QM, then, and not just QM, but comp too (which >>>>>>> can >>>>>>> only >>>>>>> please you, I guess). >>>>>>> >>>>>>> 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 >>>>>>> [email protected]. >>>>>>> To unsubscribe from this group, send email to >>>>>>> [email protected]. >>>>>>> For more options, visit this group at >>>>>>> http://groups.google.com/group/everything-list?hl=en. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups >>>>>> "Everything List" group. >>>>>> To post to this group, send email to [email protected]. >>>>>> To unsubscribe from this group, send email to >>>>>> [email protected]. >>>>>> 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 [email protected]. >>>>> To unsubscribe from this group, send email to >>>>> [email protected]. >>>>> For more options, visit this group at >>>>> http://groups.google.com/group/everything-list?hl=en. >>>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups >>>> "Everything List" group. >>>> To post to this group, send email to [email protected]. >>>> To unsubscribe from this group, send email to >>>> [email protected]. >>>> 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 [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]. >>> For more options, visit this group at >>> http://groups.google.com/group/everything-list?hl=en. >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Everything List" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> 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 [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/everything-list?hl=en. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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