Thanks for the graphic. (I've been meaning to draw out a something very similar but I am terrible at getting around to things.)


Quote Originally Posted by kujoestars View Post
In other words, by Occam’s Razor, time travel can never change what has already occurred; only create a new outcome independent of the original.
I'm not sure that Occam's Razor (loosely: simple theories are preferable to complex ones) is the right thing to be invoking, but otherwise yes, more or less.

The time traveller can affect the world around them, but those actions either become part of "how it always happened" or, if they create a situation that is incompatible with what they know as history, that forces time to diverge so the new incompatible events don't affect the original version. The traveller can still remember the events of the original timeline, but they cannot return to it because they have forced themself onto a different path through time.