There is no particular reason that all things must be reducible to a single world map without loss.
As I understand, MWI is empirically equivalent to other interpretations of quantum mechanics. You should be able to justify any particular course of action without a metaphysical commitment to the reality of unobservable components of the universe's wave function.
"Empirically equivalent" need to be unpackaged when it comes to MWI. Quantum immortality is a kind of empirical observation it's just not a shared, intersubjective observation of the kind science turns into theories (and the observations it predicts might not let you distinguish it from other kinds of Big Universe immortality).
Today's post, Living in Many Worlds was originally published on 05 June 2008. A summary (taken from the LW wiki):
Discuss the post here (rather than in the comments to the original post).
This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Why Quantum?, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
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