From Chapter 61:
(weighing, Minerva knew, the possibility that he might want to go back more than two hours from this instant; for you couldn't send information further back in time than six hours, not through any chain of Time-Turners)
If information cannot travel back more than six hours, and a "soul" (stored on a Horcrux) is information (as Quirrell describes it), then it is a reasonable guess that the soul cannot travel over a spatial separation of more than 6 light-hours. Further than that, and it seems the soul parts must fall out of synch, though exactly what happens then is anyone's guess. Does Quirrell die? Are there two separate Quirrells, one stranded permanently on Pioneer, and the other on Earth? Can the one on Earth be killed, even if the one on Pioneer is never destroyed?
Could this constraint apply in other ways? Suppose magic is the result of something that responds to the wishes of witches, as suggested at one point. If that something is Earth-based, perhaps a wizard on an outbound spacecraft would stop being able to do magic when he reaches 6 light-hours out. An interesting experiment.
Harry might be able to realistically do an experiment similar to this as a first year if there is a magic spell that lets you communicate with an object. He could use a spell to accelerate that object to a very high speed and then check in on it as it approaches the 6 light-hour point.
The next discussion thread is here.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 85. The previous thread has long passed 500 comments. Comment in the 15th thread until you read chapter 85.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15.
As a reminder, it’s often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: