On Wed, Apr 15, 2015 at 12:42:30PM -0700, meekerdb wrote: > On 4/15/2015 12:58 AM, LizR wrote: > >On 14 April 2015 at 14:05, meekerdb <[email protected] > ><mailto:[email protected]>> wrote: > > > > On 4/13/2015 4:35 PM, Bruce Kellett wrote: > > > > LizR wrote: > > > > > >I believe it's an open question as to whether these systems (angle > >of rotation of a magnet for example) are continuous or quantised. > >If quantised then there are merely a (perhaps) very large number > >of branches but no measure problem. > > I'm quite willing to say that there can only be finite precision in > any physical measurement, so the measurements are effectively > quantized even if the theory is built on real numbers. But I don't > think that solves the measurement problem. It doesn't justify > considering all the possible values equi-probable; that requires > some symmetry principle. > > Brent >
A continuum of probabilities is not a problem for COMP. UD* (the trace of the UD) is a continuum object (somewhat paradoxically :) - I know a few people have tripped up on that). What is a problem is that measure is not uniquely defined on continuums. It's not even uniquely defined on the real interval [0,1], although there is a standard one we can choose, which correponds to our measuring sticks. What I was trying to get at, though haven't fully succeeded in, is to pin down the measure to a unique possibility by considering symmetries (eg the WM teleporter case) and assigning equipropbability to those. This is how you fix the standard measure on [0,1] - if you assert that [0,0.5] and [0.5,1] have equal measure, and that [0,0.25] and [0.25,0.5] have equal measure and so on down the line, you actually fix the measure of the unit interval to being the standard measure. Cheers -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics [email protected] University of New South Wales http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- 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.
