Well, every story that has people traveling or communicating faster than light basically has not-well-defined time travel in it. Which includes most scifi ever written, I'd guess.
That's not really what I meant. There are well-defined frameworks of physical law that permit faster-than-light travel. Newtonian physics is an example. So even though FTL travel requires some suspension of disbelief, you're not usually at sea about what the rules are that govern the phenomenon. It's not like magic.
The problem with the way time travel is often depicted is that it is like magic. There's no clear set of rules constraining which properties of the time slice can change when the traveler returns to it, and which must remain the same. Surely the...
EDIT: New discussion thread here.
This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. With two chapters recently the previous thread has very quickly reached 500 comments. The latest chapter as of 17th March 2012 is Ch. 79.
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: one, two, three, four, five, six, seven, eight, nine, ten.
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: