Everett MWI is none other than ordinary QM with projectors onto outcomes that are treated as the world of the observer. Since the projector is a diagonal set of units in the unit operator over the Hilbert space the idea is that the states observed "projected out" are only so in the frame or world of the observer. These other states however persist, and these other worlds are just the results of projector operators on the total state. In one sense this is really no different than Copenhagen interpretation use of projector operators. The only difference is the total unitarity of the quantum world is stated to exist because the projector is a fabrication of our observer frame. In CI and other collapse interpretations the projector is treated as not just a frame dependency but as a hard objective outcome. Ultimately the problem is that since the projector operator is idempotent and has no inverse it is not a proper quantum mechanical operator. It is neither unitary or Hermitian. So quantum mechanics is completely silent on the meaning of the projector. The meaning of the projector operator is entirely fabricated by us. LC -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.