It seems that it is meaningless to talk about an absolute measure on the ensembles for the multiverse.
However, we can make real progress by simply appealing to principles of symmetry. For example, when an atom emits a photon it seems reasonable to assume there is 50/50 chance of measuring "up" versus "down". How could it be anything but 50/50? This is a statement about real, absolute probabilities of outcomes without any need to derive the result from some underlying measure on the infinite ensembles of the multiverse. It is interesting and perhaps no coincidence that the best way to understand physics is to focus attention on the underlying principles of symmetry, invariance and equivalence. - David --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.797 / Virus Database: 541 - Release Date: 11/15/2004