Another month, another rationality quotes thread. The rules are:
- Please post all quotes separately, so that they can be upvoted or downvoted separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
- Do not quote yourself.
- Do not quote from Less Wrong itself, HPMoR, Eliezer Yudkowsky, or Robin Hanson. If you'd like to revive an old quote from one of those sources, please do so here.
- No more than 5 quotes per person per monthly thread, please.
- Provide sufficient information (URL, title, date, page number, etc.) to enable a reader to find the place where you read the quote, or its original source if available. Do not quote with only a name.
The piece that is new is showing that only equal amplitude observers can be thought of as "equivalent" for their definition of equivalent. Previously, one "obvious" thing to try to do was to weight different "worlds" equally, and this answers that objection.
But also important, its actually pretty clear. A lot of quantum foundations papers are rather poor, its nice to see a contribution thats well reasoned.
Edit to add: Just because I think its interesting and clear doesn't mean its correct. In particular, by neglecting the small off diagonal terms in the density matrix they are doing exactly what Everett did in his original derivation, which is only valid in the limit of infinite interactions.