There's actually, unless I've made a stupid mistake, an even better algorithm that is Truing computable, if very slow:
every time the value of a bit may depend on future events, split the universe and calculate both possibilities. If a branch ever implies a paradox prune that branch and pretend it never happened.
Actually, while this indeed would require a ludicrous amount of branching for an universe where arbitrary chunks of matter can be transported back to any given plank time, all those branches would need to be computed anyway for MWI quantum mechanics. So all you're really doing is tweaking the MEASURE of each branch.
Hm... sounds right. This also has the fairly disturbing implication that, while people only ever remember consistent time loops, the distribution of mind-moments currently experiencing time loops is not weighted towards consistency, and thus most of them cease to exist as soon as the time travel event fails to happen in a way that would have formed a consistent loop.
Update: Discussion has moved on to a new thread.
The hiatus is over with today's publication of chapter 73, and the previous thread is approaching the 500-comment threshold, so let's start a new Harry Potter and the Methods of Rationality discussion thread. This is the place to discuss Eliezer Yudkowsky's Harry Potter fanfic and anything related to it.
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: one, two, three, four, five, six, seven. The fanfiction.net author page is the central location for information about updates and links to HPMOR-related goodies, and AdeleneDawner has kept an archive of Author's Notes.
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: