2009/5/14 ronaldheld <ronaldh...@gmail.com>: > > read Aixiv.org:0905.0624v1 (quant-ph) and see if you agree with it

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This part at the end, proposing an empirical method of distinguishing between MWI and single world interpretations and reminiscent of quantum suicide experiments, is interesting: "Finally, suppose, notwithstanding all the arguments above, that we arrive at an Everettian theory that, while perhaps ad hoc and unattractive, is coherent – for example, some version of the many-minds interpretation[15]. It is generally believed that, without very advanced technology which allows the re-interference of macroscopically distinct branches, such a theory will necessarily be empirically indistinguishable from Copenhagen quantum theory. The following argument against this conclusion relies on anthropic reasoning and also on the hypothesis that species may evolve a consistent preference for or against higher population expectation over higher survival probability. An- thropic reasoning is notoriously tricky to justify, and we may anyway not necessarily have evolved demonstrable consistent preferences one way or the other, so the argument may not necessarily have practical application. Nonethe- less, it does show in principle that evolutionary evidence could make many-worlds theories more or less plausible. Consider a simple model of two species A and B, both of which begin with population P and are oﬀered, each year, the option of doing something that depends on a quantum event and carries a 0.5 probability of extinction and a 0.5 probability of trebling the species population. Suppose that, if they reject the option, their population remains constant, as it does in between these decisions. Species A is risk-averse, and so always declines the option. Species B is risk-tolerant, and instinctively driven to maximise expected population, and so always accepts. Now let N be a large integer. After N years, if one-world quantum theory is correct, species A will have population P, and species B will have either population 0 (with probability (1−( 1 2 )N)) or population 3N (with probability ( 1 2 )N). In other words, species B will almost surely be extinct. If these are the only two species, and you are alive in the N-th year, almost certainly you belong to species A. If many-worlds quantum theory is correct, species A still has population P in all branches. Species B has population 0 in branches of total Born weight (1 − ( 1 2 )N), and population 3N in branches of total Born weight ( 1 2 )N. Now, if anthropic reasoning is justiﬁable here, and you are alive in the N-th year, almost certainly you belong to species B. (There are ( 3 2 )N times as many minds belonging to species B as to A after N years.) In other words, there is a sense in which long-run evolutionary success is deﬁned by diﬀerent measures in one-world and many-worlds quantum theory. If anthropic reasoning were justiﬁable, then one could in principle infer whether one-world or many-worlds quantum theory is likelier correct by seeing whether one belongs to a Born-weighted expected population maximising species or to a risk-averse species that seeks to maximise its Born-weighted survival probability. Readers may thus wish to consider whether their species has evolved a coherent strategy of either type." -- Stathis Papaioannou --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---