Agree that absolute coordinates are unnecessary. But de-indexicalizing can destroy information about your location in the world, depending on how you do it.
The way I would de-indexicalize Sleeping Beauty is to say there are 3 possible centered worlds when Beauty wakes up: heads/Monday, tails/Monday, and tails/Tuesday. There isn’t any need to say only one interview counts.
A possible reason for including this indexical information: Beauty is a real person, she might be curious what day it is, and what day it is might affect her plans for that day (e.g. maybe she is allowed to write letters that are read after the experiment is over, and which day it is affects which letter she wants to write). She should be able to update on local information (e.g. overhearing people talk about which day it is) to learn which day it is.
By de-indexicalise I meant to remove indexicals. The centered possible worlds approach uses indexicals, so it would be unusual to call that de-indexicalisation. It’s the other approach instead—choosing a version of probability theory that supports indexicals. So you can either remove the indexicals or use a theory that supports them.
Agree that absolute coordinates are unnecessary. But de-indexicalizing can destroy information about your location in the world, depending on how you do it.
The way I would de-indexicalize Sleeping Beauty is to say there are 3 possible centered worlds when Beauty wakes up: heads/Monday, tails/Monday, and tails/Tuesday. There isn’t any need to say only one interview counts.
A possible reason for including this indexical information: Beauty is a real person, she might be curious what day it is, and what day it is might affect her plans for that day (e.g. maybe she is allowed to write letters that are read after the experiment is over, and which day it is affects which letter she wants to write). She should be able to update on local information (e.g. overhearing people talk about which day it is) to learn which day it is.
By de-indexicalise I meant to remove indexicals. The centered possible worlds approach uses indexicals, so it would be unusual to call that de-indexicalisation. It’s the other approach instead—choosing a version of probability theory that supports indexicals. So you can either remove the indexicals or use a theory that supports them.