The costs to switch beliefs are sometimes high. In particular, changing scientific theories is very costly in terms of retraining, revising textbooks and curricula, trying to figure out which past results are still meaningful and which are now incoherent, etc. I am prepared to tolerate a certain amount of theoretical cruft for the sake of having old research papers remain readily readable.
MWI vs collapse theories is an interesting case in point. There doesn't seem to be a simple and clean way to derive the Born Rule in MWI. From a practical point of view, it's much better to just stipulate the Born rule -- to say that we can ignore any part of the wave function that didn't match with our measurement -- than it is to assume this exponentially* growing entangled state that we will never perceive. It might be that MWI is simpler in some sense, but talking about "collapse" is a much clearer way to explain what we are really doing mathematically.
*I am using the word in its precise sense.
Today's post, Collapse Postulates was originally published on 09 May 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 Quantum Non-Realism, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
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