Part 1 - to your first sentence: If you accept quantum mechanics as the one fundamental law, then state information is already nonlocal. Only interactions are local. So, the way you resolve the apparent ‘action at a distance’ isn’t to deny that it’s nonlocal, but to deny that it’s an action. To be clearer:
Some events transpire locally, that determine which (nonlocal) world you are in. What happened at that other location? Nothing.
Part 2 - Same as last link, question 32., with one exception: I would say that |me(L)> and such, being macrostates, do not represent single worlds but thermodynamically large bundles of worlds that share certain common features. I have sent an email suggesting this change (but considering the lack of edits over the last 18 years, I’m not confident that it will happen).
To summarize: just forget about MWI and use conventional quantum mechanics + macrostates. The entanglement is infectious, so each world ends up with an appropriate pair of measurements.
Part 1 - to your first sentence: If you accept quantum mechanics as the one fundamental law, then state information is already nonlocal. Only interactions are local. So, the way you resolve the apparent ‘action at a distance’ isn’t to deny that it’s nonlocal, but to deny that it’s an action. To be clearer:
Some events transpire locally, that determine which (nonlocal) world you are in. What happened at that other location? Nothing.
Part 2 - Same as last link, question 32., with one exception: I would say that |me(L)> and such, being macrostates, do not represent single worlds but thermodynamically large bundles of worlds that share certain common features. I have sent an email suggesting this change (but considering the lack of edits over the last 18 years, I’m not confident that it will happen).
To summarize: just forget about MWI and use conventional quantum mechanics + macrostates. The entanglement is infectious, so each world ends up with an appropriate pair of measurements.