If there is no experimental difference between MWI and Copenhagen, the "proper" belief is the one that serves your purposes other than seeking universal truths.
I'm realizing we're probably both confused by the word "belief."
Newtonian physics has been proven wrong, but it's still a perfectly reasonable system to use for, say, landing a man on the moon. I thus have the belief "Newtonian physics is inaccurate under certain extreme conditions" and "Newtonian physics is an accurate-enough model for a specific domain of problems, which includes basically every practical problem I am likely to run in to in my daily life".
Given that both MWI and Copenhagen are accurate models of the data, I ...
This is the public group instrumental rationality diary for the week of August 6th. It's a place to record and chat about it if you have done, or are actively doing, things like:
Or anything else interesting which you want to share, so that other people can think about it, and perhaps be inspired to take action themselves. Try to include enough details so that everyone can use each other's experiences to learn about what tends to work out, and what doesn't tend to work out.
Thanks to everyone who contributes!
Last week's diary; archive of prior diaries.
(Sorry for being late this week -- I'm on vacation and got distracted :-)