But time travel before the reboot films was never branching. All the talk about 'fixing and 'altering' time wouldn't make sense otherwise. Also, Data's head in 'Time's Arrow'.
Of course it does. It's just a useful analogy for talking about the flow of cause and effect. Remember Doc Brown's blackboard demonstration in
Back to the Future Part 2? That was a series where the timeline was directly overwritten, but it was still useful for the sake of discussion to use branching timelines as a visual metaphor to convey the concept.
some have also speculated that events in Discovery may feed into the events leading up to the creation of the Kelvin timeline.
The "some" who speculate that are ignorant of basic facts. The Kelvin Timeline was explicitly created by Nero's arrival in 2233, 23 years before the start of
Discovery. DSC has a Klingon war take place in 2256-7, while
Into Darkness is set in 2259 and says that there have only been a few minor skirmishes between Starfleet and the Klingons. Also, DSC has the
Enterprise in active service in 2256-7 and acknowledges that the events of "The Cage" happened in 2254, while the Kelvin
Enterprise isn't even launched until 2258.
BTW when I said it was a fixed timeline I meant that we know what happens after this series and for the next 100 years and more, this is the problem when you have time travel in a prequel series.
But I was the one who introduced the phrase "fixed timeline" into this discussion to mean something totally different from that. Since I was the one using the term to make a point, I need you to understand what
I meant by it in the context of that explanation.
Again, I'm not talking about Trek in general. I was addressing the single, very specific question of whether a time traveler could be expected to remember alterations she made to her own past. Please try to understand my comments within that context.
Interesting to note that they succeeded in the 12 Monkeys TV series in spite of the Film ending with the statement that it could not be changed.
Well, naturally, since the needs of a TV series are different from the needs of a film. If history can't be changed, that can drive a single story, but it's harder to build a continuing series around the premise. Many time-travel series share a common premise that it's possible but difficult to change history; that way, there's some hope that the characters could achieve their goal, but it's not something they can do easily and thus it can sustain years' worth of stories.
Although there have been occasional series that used a fixed-timeline model.
Gargoyles got some clever stories out of self-consistent causal loops and its unbreakable rule that time was immutable.
Babylon 5 had a self-consistent time loop as an integral part of its saga.
Andromeda followed plausible physics, including an immutable timeline, for its first 2 seasons, but the later showrunner threw that out. Still, those are all series where time travel is only a secondary or occasional element rather than the central focus. Series that center on time travel generally make it mutable, unless their focus is more on visiting or traveling in the past than on causal paradoxes.
Doctor Who posited an immutable timeline in its first season, only to throw that out a year later and do a story ("The Time Meddler") about protecting the timeline from change.
The Time Tunnel mostly presumed an unchanging history; the only things Tony and Doug had the ability to affect were events that history didn't document, so that they didn't already know the outcome and could still make a difference (presumably they were part of those events all along but just didn't know in advance whether they'd succeeded). Although in later episodes, the writers partly forgot that rule and did stories built around the risk that history
could be changed, even though it never actually was.