Pierz wrote:
On Thursday, August 13, 2015 at 5:00:05 PM UTC+10, Bruce wrote:Pierz wrote: > > And it's true, you can't determine probabilities by counting branches. > > Not by counting the number of eigenvalues, but by treating the > probability amplitude associated with each eigenvalue as a measure of > underlying worlds - well that was my understanding. So you have, in fact, achieved nothing. You have to impose a probability interpretation that is external to MWI, whether given by the number of branches or not. Postulating an infinity of branches in every case, and then using the Born rule to give a probability measure over thisinfinity, is all rather much a waste of time. Well it would be, if it didn't save you from the ugliness of "collapse". It doesn't let you derive the Born rule, but its intention is not to explain the probabilities, which are not explained in standard Copenhagen QM either. Its intention is to provide a framework within which collapse and the associated measurement problem are eradicated.
One can avoid collapse in much simpler ways. It is clear that the plenitude of worlds you suggest do not actually play any role, let alone an essential role. If they do not give the probabilities, then it is simpler to follow Everett's original idea and have one world for each dimension of the underlying Hilbert space. Then one would get probabilities from elsewhere. Occam's Razor surely comes into play here to toss out Deutsch's extravagance.
One's dislike of a physical collapse postulate cannot be used to justify just anything -- there are sensible proposals, and then there is David Deutsch.
Bruce -- 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 http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
