But this seems to suggest that if someone survives lots of QI experiments, they should update massively in favour of QI, but nobody else should update at all
It seems like an observer should likewise update in favor of QI in this case. If I know that you have survived many QI experiments, don't I have just as much justification for updating in favor of QI as you do?
No, because from your perspective, me surviving is just as unlikely under QI as under not-QI. If I die on the result of a quantum coinflip, then the universe diverges into two branches. I can only observe the one where I survive, but that doesn't mean it doesn't exist. You're equally likely to observe either of them.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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