Perhaps the reason he didn't is because you would have sent that information back in time, and so he couldn't.
But every time someone uses a time turner, they send that information into the past. If it didn't block them then, why would it block them now?
Another possibility is that information loses "coherence" the further back it travels.
There are ways of fixing that. For example, you could send people back in groups of three. Then you have them go back unless they're stopped by at least two people.
Or maybe it is possible, but insanely dangerous.
That's possible. The longer the time stream, the more likely that the closed time loop you end up with involves a hurricane or worse. I believe there was a book where the world ended because someone didn't think about that. You could prevent it by allowing a "maybe", so long as you make it likely enough that something you didn't think of doesn't become more likely.
Perhaps the reason he didn't is because you would have sent that information back in time, and so he couldn't.
But every time someone uses a time turner, they send that information into the past. If it didn't block them then, why would it block them now?
Because you would have sent that information back in time. It didn't block them "then" because they weren't going to send the information further back. The effect could be more subtle - instead of preventing you from succeeding, it could prevent you from trying (don't mess with time) or ...
The next discussion thread is here.
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 85. The previous thread has long passed 500 comments. Comment in the 15th thread until you read chapter 85.
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.
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: