I wonder if that is ever considered. Change one thing and you change everything even if it is correcting a wrong to a right.
Didn't Steven King write a book where JFK's assassination was prevented but nuclear war came about through a series of unintended consequences?
Most generic time travel stories just tell the main characters not to make any major history changes, for example don't kill hitler, dont prevent the Kennedy assassination etc.
But all events in the ENTIRE WORLD are based on EXACTLY TIMED COINCIDENCES. The fabric of time is the most delicate thing in the entire universe. All people in the world are the genetic result of a certain sperm connecting with a certain egg. It would take VERY LITTLE alteration of historical events to cause slight changes in who meets and has sex with who, or even if its the same people as the original timeline them having sex the same time of day in the same position etc.
So traveling back in time would create a huge number of DIFFERENT PEOPLE in the world. Even what you eat for lunch that day could affect which sperm reaches the egg resulting in a different person being born.
It would be impossible to not majorly change history, ANY interactions at all would mess up all of the exactly timed coincidences that make up the world.
This is coming from the perspective of a full-time Whovian, so...
The alternate theory to the butterfly effect is that there are certain "fixed points in time" which anchor the main flow of history. Anomalies by and large resolve themselves so there are only minor changes.
For example, right now Lucy's mother is well but her sister doesn't exist, which seems like a major change. But maybe in this timeline Lucy's mother eventually gets sick anyway. And in the original timeline, Lucy's sister dies in 2017. So by the end of next year, things would have been about the same.
Note: I literally completed Lucy's "Maybe we don't get to make it up as we go, maybe some things are..." with "fixed points in time. :p
-----------------------------
I miss Giles.
check out http://www.imdb.com/title/tt2879552/
shareI think of time travel as fiction. People always talk about butterfly effect. How do you know would happen if changed history? Time travel doesn't exists it's fiction there for it doesn't have to be 100 percent logical. Which mean there can be different adaptations about time travel. Each adaptation should create there own rules on how perverse or change a time line. Create original theme and just go with it. As, it's historical accurate when they go into the past.
shareOne talks about changing history, butterfly effects etc,etc.
If one travels back in time make sure nothing alters history.
Well, surely the fact there is a time traveller present changes history, someone who wasn't there before interacting with others, even if it's minor.
Not that time travel will ever be possible!
The Butterfly DID take effect in the first episode. When Lucy got back to the present her Mom was not sick and her sister Amy did not exist.
Schrodinger's cat walks into a bar and doesn't.
Didn't Steven King write a book where JFK's assassination was prevented but nuclear war came about through a series of unintended consequences?