"But bringing up the quantum Hamiltonian? FTL signalling? Su3su2u1's analysis is correct."
Is it? Noether's theorem implies the Hamiltonian is conserved. The Hamiltonian is the quantum operator that give you the energy of a system. If energy conservation is violated, either the basic equations of quantum mechanics don't hold, or (magical) physics is not time invariant. I'm not saying Harry is being technically precise but he's not completely wrong, either.
No, he's certainly not completely wrong, but he's bringing up irrelevant complications and missing the main point. Quantum vs classical has nothing to do with it, for example.
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 122, which is the final chapter of the story.
Happy once-in-a-century Pi Day! (3/14/15 == 3.1415)
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.)