Because I need a shorter link to which I can direct people when I try to explain why the temporal mechanics in season two of Star Trek: Picard are actually quite well done, I am making this blog post. It is an updated version of content I have previously posted on Facebook and Twitter.
Some fans I’ve seen talking about the latest developments on STAR TREK: PICARD seem confused about the temporal mechanics of the whole thing. (SPOILERS follow)
The writers of Star Trek: Picard are depicting a single timeline in which one set of quantum potentials (A) that had been dominant are suddenly deprecated (and therefore inaccessible) when something causes a new set of quantum potentials (B) to overwrite set (A), with the trigger event pegged to April 15, 2024.
Because the quantum potentials of set (A) have been overwritten, unless and until the trigger event on April 15, 2024, is corrected, there can be no accessing the events of set (A). Any time-travel backward from the altered future of set (B) will be into its own past, and any events altered in that past by time-travel actions from the darker future of the Confederation [set (B)] will contribute to an altered past [set (B)’s past].
This is why the La Sirena can journey only into the past of the set (B) altered version of the timeline; even when it journeys to a point before the divergence event, it is still in the altered timeline.
When this overwriting of the timeline’s quantum state occurs, thereby changing the future that follows to potential set (B), it also changes any past events that would have been caused or influenced by the now-lost future of set (A). Consequently, past events linked to quantum state potential set (A), if they occurred at all in any form, are now linked to the conditions of quantum state potential set (B).
Ergo, bringing about an altered future also creates an altered past.
That doesn’t mean that *some version* of past events we knew from set (A) never occurred. However, the specific details of those events might differ from those we remember. They might have been undertaken with different intentions, and involved different persons, with varying outcomes.
For instance, a set (B) alternate-future version of James T. Kirk (alt-Kirk) might have been sent by the Confederation to violently abduct whales from now alt-1986, in order to destroy the Probe in alt-2286. During that mission to the past, alt-Kirk encounters alt-Bus Punk and uses a Kirk-Fu neck-chop to neutralize him. Now, when confronted on the bus in alt-2024, alt-Bus Punk reaches for his neck not because he was pinched by Spock but struck by alt-Kirk.
The callback joke doesn’t invalidate the temporal mechanics by introducing a paradox, because it leaves open the possibility of an alternate explanation for alt-Bus Punk’s reaction. No one says on-screen that it was Spock who hurt him, or that he experienced a Vulcan nerve-pinch. Yes, it’s implied for the sake of a good easter-egg gag, but it’s also left vague enough that it does not constitute a paradox or in any way invalidate the underlying temporal mechanics of this story.
Continuing this thought experiment, if the future of Star Trek: TNG never happened, then the mission to 1893 from “Time’s Arrow,” Parts 1 & 2, if it happened at all (and it might not have) might have transpired in such a way that Guinan did not meet Picard in the past. But because of El-Aurian temporal sensitivity, she senses the temporal discordance when he introduces himself to her. She both doesn’t know him but knows she once did. A paradox, but one that fits the temporal mechanics and El-Aurian abilities as described.
It might seem confusing or contradictory to canon, but it’s not. It’s an internally consistent set of temporal mechanics, and one that comports with previous depictions of time-travel in Star Trek.
In theory, if our heroes succeed at fixing the 2024 divergence event, thereby restoring the original state of the timeline and consigning its altered state back to the dustbin of unrealized quantum possibilities, they will still need to fix their own mistakes in 2401 in order to prevent a repeat of the temporal collapse.
But that’s another problem, one for the PICARD season finale.
Curiously, the diagram for the time-travel shenanigans of PICARD Season 2 looks a bit like the diagram I had to work up for book three of the Star Trek: Coda trilogy (though the one for Oblivion’s Gate was even more complicated, as you can see).
Part of me thinks the Borg-Altered Earth timeline’s Borg Collective could eventually have become the alt-Borg who ask Picard for help in 2401 … but that’s just my own fannish imagination trying to tie them together.