Earlier quoted context omitted.
Right, and it is interesting because 'quantum events' happen very often, which would seem to indicate an infinite number of universes, which means that any particular fantasy you'd like to think about is occurring in some of them. The bit I get fuzzy at: something I believe, but without proof, is that any scheme that involved any communication between universes would fundamentally violate a ton of basic physics princ…
Check out the concept of a "Everett-Wheeler telephone". If quantum mechanics had a non-linearity and... some other conditions, then you could use it to send, uh, some information between two sides of a branch point, uh, once, I think. At least, you could send a single bit from one side of the branch to the other. I think the idea is, if there are non-linearities in time evolution, then either [the thing described abo…