On a tangentially related note, the tabletop roleplaying game Continuum has, IMO, the most interesting description of time travel and a time travellers community.
The premise is simple. What is the most logical thing for the first time traveller to do? He would travel to the future to get his hands on the most advanced time machine possible. In the end, the best is the human mind. They time (and space) travel with a simple thought.
It has a single "timeline", i.e. changing something in the past doesn't "split the timeline" but creates a paradox, that translates to "frag" on all people related to the changed action. This makes people want to correct these paradoxes.
Example, I go back in time and kill Hitler. It frags a LOT of people. The good guys want to correct the frag. They could go back in my timeline and prevent me from doing it, fragging me. If they don't want to frag me, they could switch Hitler with a Robot or something. I don't get fragged because still I shot something I though was Hitler, yet Hitler remains alive.
Wouldn't we as well need a counterpart to "frag" such as "pop" for all the people saved/born due to the change? Then if the "good guys" corrected the original "frags" those "popped" people would be re-"fragged" which would cause a split group of "good guys" to attempt to "correct" the previously "corrected" history?
The universe is kind of a mutable thing full of "sentient force" (it's time travellers). When a paradox is formed, it's defense mechanism kicks in to eliminate the paradox. That defense mechanism is the good guys (the continuum).
Frag is associated with what you KNOW. Information is usefull but very dangerous.
Imagine this, I go to Auschwitz and see all that horror. I decide to kill Hitler and succeed. I just fragged myself, because I know I killed Hitler (therefore, the Holocaust never happened) yet I saw/know what happened if he were alive. Frag is like being "out of sync" with the universe. If I don't feel frag, it means the good guys intervened, and nullified my action. Of course, as punishment they would probably frag me in another way.
Why do they prevent the killing of Hitler? Because they and their frieds may have/will have seen the consequences of Hitler's actions so it's in their interest to prevent the paradox.
Practically, it doesn't matter what really happened, just that it happened as remembered by the coninuum, and that the consequences remain the same. Another example, by some means, JFK's father is sterile. He can't concieve JFK This is a problem as JFK is known to exist. The continuum may stealthily inseminate JFK's mother for him to be born. In the grand scheme, it may be even impossible to know if JFK's was always sterile or if some outside force made him sterile. The universe must BE as it is remembered.
Higher level continuum members start realizing that, in fact, free will does not exist. You just have to do what you have to do, and have fu doing it. (This is also the main focus of disagreement with the bad guys.)
I like the book's example of simple frag with the beer.
So the setup is that you and your time travelling buddy are watching the big Sportsball match on TV in both of your relative presents.
You want a beer so you go to the fridge and there isn't any. So you jump Downstream a couple of minutes, grab a brew and jumps up. Uh oh, don't drink and Span because you just fragged your friend as you are both drinking the same beer.
Your friend is naturally peeved and tells you to fix it. So, what you do is:
* Buy a pack of the same brand of beer and put it in the fridge
* Put a note on one of the bottles telling yourself and your friend not to touch it
* Span (Jump) Upstream a few hours so it's cold then jump back to just after you took the beer from the fridge yourself and put the new beer (the one that was cooling in the present -> future) in so your friend can grab it when he wants a beer.
* You also have to not run into yourself so you jump back up to after the point where you left for the future so as punisment you miss the big sportspile. However all is well because you friend just fills you in regularly and you both enjoy your tasty beverages.
The premise is simple. What is the most logical thing for the first time traveller to do? He would travel to the future to get his hands on the most advanced time machine possible. In the end, the best is the human mind. They time (and space) travel with a simple thought.
It has a single "timeline", i.e. changing something in the past doesn't "split the timeline" but creates a paradox, that translates to "frag" on all people related to the changed action. This makes people want to correct these paradoxes.
Example, I go back in time and kill Hitler. It frags a LOT of people. The good guys want to correct the frag. They could go back in my timeline and prevent me from doing it, fragging me. If they don't want to frag me, they could switch Hitler with a Robot or something. I don't get fragged because still I shot something I though was Hitler, yet Hitler remains alive.