The new thread, discussion 13, is here.
This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. With three chapters recently the previous thread has very quickly reached 1000 comments. The latest chapter as of 25th March 2012 is Ch 80.
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: one, two, three, four, five, six, seven, eight, nine, ten, eleven.
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:
You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).
If there is evidence for X in MOR and/or canon then it's fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that "Eliezer said X is true" unless you use rot13.
I know Voldemort is Tom Riddle. The scene as written (as Harry remembers it) seems to me to mean that the "strange word" was something baby Harry actually heard. Of course it might have been spoken "directly into his mind" via Legilemency or via Voldemort's consciousness or horcrux being installed in Harry's mind.
Either way, why would Harry think of it as a "strange word"? Why not just have him think that he heard the word "riddle"? It makes more sense that he heard a word he cannot recognize, namely "horcrux", and so labels it strange.
See also: first few sentences of Chapter 1. If that is the same scene, it's far more likely the word Horcrux was screamed by Voldemort (casting the Horcrux spell) than the world Riddle.
Chapters 43 and 45 don't seem to me to imply that baby-Harry actually heard the "strange word", only that for whatever reason Harry found himself thinking it. It was strange because he had (so far as he knew) no particular reason to be thinking that word.
I don't have any very convincing theory for why he had that word in his brain at that point, though. Evidently he interprets it as a message from his subconscious that he should think of Dementors as a riddle, or something like that, but probably something more is meant to be going on.