I wrote a version of this up at reddit too, but it seems to me trying to hack the laws of physics is wasted effort when we know very little about how magic works in concrete terms. We don't know what Harry can really do, how fast he can do it, or whether Voldemort would notice.
What we do know are: how Harry thinks how Eliezer thinks * what Voldemort wants
So we should be looking at things Harry could say that would advance his goal of surviving rather than trying to come up with a combination of spells, with the understanding that winning ideas are probably going to cluster around narrative interventions that EY thinks are interesting or important. A few that spring to mind:
Memetic hazard: are there things Harry could say or bring to Voledmort's attention that would pose an existential risk to him if he harms Harry
Let the AI out of the box: is there something Harry can offer Voldemort such that Voldemort goes against his stated agenda
Precommitment / timeless decision theory: are there ways Harry can manipulate the unbreakable vow to force certain conditions in the future
Learning to lose: what if Harry surrenders and agrees to join Voldemort, with a commitment Voldemort finds convincing
Unintended consequences: Harry makes a convincing case that there is no way to outthink an inevitability other than to fulfill it in terms that are advantageous to you.
I really think didactic lessons about rationality are going to be better, and more appealing to EY's sensibilities, than trying to fanwank some way to use magic to kill 38 people in a single play. We just don't have the rulebook for that.
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 113.
There is 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.)
IMPORTANT -- From the end of chapter 113: