Also, note that chapters 88 and 89 are titled "Time pressure", and the exact date and time is specified repeatedly throughout the text. In addition, there’s something funny in chapter 90: Right before Harry has the hypothermia idea, there's a discontinuity:
[The Headmaster] had vanished from where he was standing over the Weasley twins and come into existence beside Harry; George Weasley had discontinously teleported from where he was sitting to be kneeling next to his brother's side, and Fred was now lying straight with his eyes open and wincing as he breathed.
Right after Harry explains the Frigideiro, there’s this:
Fred and George started sobbing.
Which suggests a time loss (likely someone messing with Harry’s memory, the discontinuity sounds a bit like what Mr. Hat did). The sobbs might be because the twins knew what happened during that time, and realized that too long passed for the spell to do anything.
Harry also looks at the Time Turner when he gets it unlocked, and seems to notice or confirm something.
There’s a lot going on here we’re not told.
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 90. The previous thread has passed 750 comments.
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, 16, 17,18,19.
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: