Logline
La’An travels back in time to twenty-first-century Earth to prevent an attack which will alter humanity’s future history—and bring her face to face with her own contentious legacy.
Written by David Reed
Directed by Amanda Row
Note: This is a second attempt, as technical difficulties were preventing people from seeing the original discussion post. Apologies to the people who were able to comment in the original.
Our household has been coming at it from our understanding of physics, and have been since at least the 90s. It means that we’ve been watching through that lens for a very long time.
Without it, the episodes in Voyager where Harry Kim or Janeway came back to correct the timeline are meaningless. We would just assume that the unchanged timeline went forward offscreen.
This resilient river of time version offers a continuity where actions matter, and corrections to the timeline mean something more than just a shift in point of view.
As you note, multiple universes can exist but it takes something very large to do it. In Star Trek, we’re not in the infinite and ever expanding continuum of branching universes where every possible permutation of events exists. (And that version of the multiverse doesn’t stand up for hard scientists.)
So far we know that the Mirror Universe has different physics of light - something that’s so enormous that it’s hard to credit that it’s developed in any kind of parallel. It suggests some fixed events in the past development of the two universes that are extraordinarily resilient against branching.
The Romulan supernova is a major event but of a much lower order of magnitude than say the establishment of the physics of light. It seems like that would be a kind of lower bound for a branching trigger.
All to say that I agree that a Daystrom Institute deep dive would be worthwhile. In fact, it may be possible to go through onscreen canon and itemize the various events and inconsistencies that support this construct.
The Narada incursion had the benefit of three things - a black hole, a very intense ion storm, and the magical red matter. We can minimally accept that as a unique confluence of events that led to a branched rather than overwritten timeline, at least.
To support the resilient river of time model, when I was studying history in grad school I came up with this axiom: history isn’t inevitable, but it has momentum.
To put another way, any given historical event is the natural outcome of historical events before it, and therefore when changing history you’re not just trying to change the one thing, but dealing with the weight of everything before pushing the timeline in that direction. That’s why it’s so hard to change history, that - in Sera’s terms - it seems like Time itself is fighting you. Call it historical momentum, call it historical inertia, what you will. And so the more “momentous” the event, the harder it is to just change it - things will “want” to go back to the way it was.