This has been driving me nuts. For most of Star Trek’s history, the Prime timeline holds together no matter what happens to it. Kirk jumps around, Picard gets stuck in time loops, Janeway rewrites entire centuries, and the universe just snaps back like it never happened. Time feels elastic but stable.
Then Nero falls through a black hole, and everything falls apart. The Kelvin event doesn’t just make a new branch going forward. The ripple hits both directions. It rewrites history that should already be set. Starfleet looks different. Vulcan feels different. Even the technology and design philosophy seem changed long before Nero was ever born. That sounds less like a branch and more like time itself got rewritten.
Once that happens, the Temporal Prime Directive starts to fall apart. It only works if time moves in one direction. You can “fix” something when there’s a clear before and after. But if the ripple goes both ways, there is no original timeline to go back to. The moment the Kelvin universe forms, the concept of Prime reality stops being a single point.
And that’s before you even touch the Mirror Universe, which is not a branch at all. It has been running beside the Prime since the beginning. So now we have at least three full continuums: Prime, Mirror, and Kelvin. But that’s not the end of it. The Star Trek Online timeline exists as an extension of Prime, playing out events after Nemesis and even connecting to the Temporal Cold War. The licensed novels follow yet another line, continuing after Destiny and Coda, where the multiverse literally starts to collapse under the weight of too many versions.
So what is the Federation even supposed to do with the Temporal Prime Directive at this point? Which universe counts as the real one? Do you merge them? Do you pick one and call it Prime? Or do you admit that every version is its own living reality with its own moral weight?
Maybe the point isn’t fixing anything anymore. Maybe the Temporal Prime Directive is just damage control. Once time starts rewriting itself both ways and spawning whole new continuums like STO or the book universe, there’s no putting it back together. The best you can do is keep the pieces from smashing into each other and hope reality doesn’t collapse under the strain.
Wait'll you get a load of season 5 of Lower Decks.
I wish that McMahon hadn’t done that in Lower Decks and had left TNG Parallels as a one-off.
The thing is that the infinitely expanding manifold of temporal multiverses is a thought experiment in physics that doesn’t really have widespread support in physics. It also is inconsistent with how temporal mechanics are applied throughout the rest of the history of the franchise.
What SNW provides in Tomorrow and Tomorrow and Tomorrow is articulated even more clearly in Prodigy is closer to modern physics theory and is also the only way to make sense of creative choices that Gene Roddenberry dictates for the TNG Pilot ‘Encounter at Farpoint.’
When Roddenberry dictated that TNG would set World War III in the mid 21st century he also dictated that TNG and TOS are in the same timeline. That’s only possible if the franchise goes with the robust River of Time version of the physics that SNW and Prodigy articulated.
That is, there can be major forks or branchings at critical events but the smaller perturbations do not in themselves create new timelines. A Mirror Universe or Kelvin universe can be created but they are limited in number and not infinitely dividing at each and every minor decision point.
Instead, as long as key major events happen and they happen in the same order, then a timeline is preserved. Otherwise, our heros’ actions in saving the continuity WOULD NOT MATTER in any number of episodes and movies because the timeline where they fail would also exist.
So, as long as Cochrane’s ship gets to demonstrate the warp drive at the right moment such that First Contact occurs, then the Prime Timeline is preserved. There are not two parallel ones with and without the Enterprise crew onboard with him or one where the Borg were successful in stopping human contact with Vulcans.
Likewise, there isn’t a TOS version of the timeline where World War III took place at the end of the 20th century after the 1990s Eugenics War. Instead, that event has shifted back and forth in time as the Romulans have attempted to impede human development with temporal incursions and Federation temporal agents have worked to counter them.