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 chapters 91 & 92 . The previous thread has passed 500 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, 17,18,19,20.
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Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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 agree that if you solve time travel you can also solve death, but the other implication does not hold. A possible way for Harry to "resurrect" Hermione is to scan her brain, run it through an error-correcting algorithm (to reduce/remove errors introduced from decay and it being transfigured) and then "print out" a brain that is arbitrarily similar to Hermione's brain at the moment of her death. This will of course depend on the amount of computing power available to Harry, but since he is already "destined" to tear apart the stars, that will probably not be a problem. It'll also require some "minor" scientific breakthroughs.
Now, I am not at all saying that this is Harry's plan to resurrect her (In fact I suspect his plan to be very different from this), I am merely providing an example for how you can "restore" someone who is dead without being capable of time travel.
By definition, however, an information-theoretic death means that such an error-correction scheme would be impossible; such a machine would require knowledge that, by the Uncertainty Principle, cannot be attained.
Thus, if you did have that capability regardless, it could then be used to rewind an arbitrary section of the universe to an arbitrary time, which is equivalent to time travel.