watching down on us
The idea behind a stable time loop is that by committing the act of traveling back in time you aren't truly changing history, you are merely finishing up a loop that has already been started by your near-future self.
The Prisoner of Azkaban does a wonderful job of illustrating this, and the film makes it even clearer with additional loops (Hermione throwing rocks, her wolf call, etc). Before time traveling, Harry saw what he believed was his Dad, but he in fact saw his future self.
The history that takes place before your time travel has to be the "changed" history, but your time travellers also need a motivation to time travel in the first place so that they can make history the way it has always been, accidentally or otherwise.
Going back to Prisoner of Azkaban, Harry and Hermione time-traveled to save Buckbeak and Sirius because they believed they were dead, when in reality, they've already been saved by their future selves. If Harry and Hermione knew Buckbeak and Sirius were safe but didn't know that they were the ones who saved (or will save) them, then they would not have a motivation to go back in time and do it themselves, causing a break in the loop.
edited 20th Sep '11 9:10:27 PM by annebeeche
Banned entirely for telling FE that he was being rude and not contributing to the discussion. I shall watch down from the goon heavens.
Ok the issue is that time travel was used to defeat one Big Bad.
Then afterwards too much time travel brings forth a conflict (one that involves ancient giants way bigger than the present day setting giants) from the very distant past.
So in order to make stable time loops I must write the backstory in a way that allows for the possibility of time travel, correct?
edited 20th Sep '11 8:43:42 PM by Worlder