> On 28 Jul 2018, at 20:36, Lawrence Crowell <[email protected]> > wrote: > > On Saturday, July 28, 2018 at 12:44:54 PM UTC-5, Bruno Marchal wrote: > > > The whole weirdness of QM is that we can measure effects which in that > formalism entails the actuality of counterfactuals. > > Counterfactuals in QM do not have the same ontology as classical objects. > Prior to a measurement or decoherent process that shifts a superposition or > entanglement phase from a system to a reservoir of states we might say the > superposition of a quantum wave is a case of prior existing counterfactuals > in a ψ-ontic interpretation, such as MWI.
We agree. > In MWI the counterfactual continues to exist after the process as well. That was my point. OK. > In the deBroglie-Bohm interpretation the counterfactual does not exist. Here I disagree. They continue to exist in the potential so that it guides the particles correctly. It is empty of particles but still mimic a world with particles from the point of view of possible observers (lacking particles). The branches without particles must still mimic their internal observers correctly to guide correctly the particles. I agree with Deutsch when he says that the deBroglie-Bohm theory is a many-worlds theory, with one branches “more real” (having particles), and the other branches mimicked by the guiding potential. With mechanism, we cannot know if we are in the worlds with the particles or without, unless we postulate, as Bohm did, some non mechanist theory of mind. > There is in that idea on active channel for the motion of the ontic > particle.In ψ-epistemic interpretations it is odd to talk about > counterfactuals existing or for that matter anything factual prior to the > measurement of decoherence. As I have indicated QM is most likely neither > purely ψ-ontic or ψ-epistemic, so to talk about anything "existing" is a bit > strange. Physical existence is a relative notion depending on the observer. But we have the same in arithmetic with the comp. theory of mind. Bruno > > LC > > > Computationalism is more than OK with this, as it predicted that for almost > all universal machine (that is all except a finite number of exception), the > reality below its substitution level is an infinite sum of universal machine, > and above its substitution level it is a finite sum of universal machine (to > handle with). > Actually, physical decoherence saves mechanism, and QM, from solipsism. > > Grayson, you seem to dislike the many-worlds or many-dreams, but eventually, > with mechanism, all we need to assume is the many-numbers, or the > many-combinators (as I will illustrate). > > The physical reality is not a mathematical structure among others: it is the > border of the observable from a universal machine viewpoint. A very peculiar > structure implied by mechanism and a notion of correct self-reference. > > Bruno > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > Visit this group at https://groups.google.com/group/everything-list > <https://groups.google.com/group/everything-list>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
