With the finale of Loki Season 1, the MCU temporarily wraps its most time travel-intensive entry to date, so it’s time to add an addendum to my MCU chronodynamics post. We’ll recall that the multiversal superstructure of the MCU is essentially just a branching timeline, with various forms of time travel along that timeline.
We learn a great deal about time travel through the Time Variance Authority (TVA). Of course, the TVA is a very unreliable source of information, so we will largely be tempering that information with what we can directly observe. Let’s get to the main points first.
Big spoilers for all of Loki Season 1 ahead, folks!
The good news is Loki doesn’t fundamentally change the branching nature of the timeline, it just presents a governing agency for it. Branches can form and grow, and there is a way to map this deviation now. Any branch that exists exists either because the TVA allows it or because they don’t have the resources to fix it, and their judgment is rather arbitrary. They tell us themselves that major branches could be from starting a war or just being late to the office, and their technology allows them to react to these and adjust timelines in pretty sweeping ways. So while the main MCU timeline (which I called Timeline A) is allowed to continue, we don’t really know if any of the others (which I called Timelines B-G) are pruned or allowed to coexist.
The biggest twist is that the TVA was telling the truth about their mission and history–there was a big Multiversal War that they are pruning the timeline to prevent; they were just covering up a lot of information in a really suspicious way for no apparent reason.
Now, as for the particulars we learn from Loki:
- There is a primary timeline, referred to as the Sacred Timeline. Everything that occurs in this timeline is approved of by the TVA. At first glance, it appears to be the same as Timeline A.
- Time travel events branch the timeline. The TVA is able to measure just how far these branches deviate from the Sacred Timeline. “Variance” is the measure of how far the branch deviates. We aren’t told how variance is measured, so we’ll just have to accept that it can be measured.
- It appears possible that branches can stay relatively close to the Sacred Timeline without deviating too much. This seems to indicate that the “Sacred Timeline” is actually multiple timelines (one of which is Timeline A) that all follow very closely to each other, like the braiding of a rope.
- Of course, some branches do deviate a great deal, as one would ordinarily expect with the butterfly effect. An event that precipitates these changes is called a Nexus Event. Technically, the time travel event leading to these branches should almost always be the Nexus Event, but the TVA judges them based on what they feel was the most important event leading to the deviation.
- The TVA is able to manipulate branches and objects from those branches via “pruning”.
- Pruning an object ostensibly destroys it so it cannot interfere with the branch anymore. This lets the branch continue without much further deviation. Since energy cannot be destroyed, what actually happens is it sends the object to the Void, aka the End of Time.
- “Resetting” involves having an area-of-effect charge prune everything within a given radius. It appears that the affected volume left behind is filled in by the adjacent Sacred Timeline. It implies there is some elasticity to the timeline, as it will effectively heal itself, but it could just be multidimensional osmosis. This is effectively like the TVA giving the branch a quick kick back towards where they want it. This indicates that, e.g., the timeline that Loki was pruned from spawns a new Loki to fill in. This is somewhat weird mechanism, no?
- The TVA makes a major effort to prune before branches deviate by a certain extent–the Red Line. Apparently after that point, the branch is deemed a lost cause and is completely destroyed.
- The TVA’s true ultimate mission is to prevent a multiversal war between variants of Kang. In theory, every alteration they make is for that goal. It is possible that the Red Line is a prediction that that branch will generate a hostile Kang. Any arbitrary adjustments made by the TVA could be based on foreknowledge of what key events lead to this. So the most likely conclusion is if Timelines B-G get to remain unpruned, it is because the TVA knows they won’t lead to a hostile Kang, and if they were pruned it’s because they do. It doesn’t directly have to do with how different the timelines are (after all, the timeline where Cap remains in the past or where Thanos disappears in 2014 would be very different), but on what Kang will be born in that branch.
- The TVA appears to be headquartered in its own universe outside the Sacred Timeline. The fact that Infinity Stones are powerless there suggests it is not in any branch of the Sacred Timeline, but rather somewhere else in the multiverse. While they can observe the various timelines there, time always moves forward at the TVA.
- At least, that is, until Sylvie kills Kang. We then find out that the TVA can be overwritten as well. This was only sprung on us at the last minute, so we won’t know much of the specifics until season 2. It looks like, since it is its own separate timeline, the TVA can also branch.
- Until we learn the specifics, we can’t say how Kang managed to get there and branch it. Killing Kang shouldn’t cause any instantaneous changes to the timeline, so it seems more likely that during the chaos precipitating his assassination, one of the Kangs on the Sacred Timeline was able to launch his crusade and found his way to the beginning of the TVA.
- It is possible that the TemPads are designed to always send the user forward in time a bit when they return to the TVA, which is why time at the TVA always appears to move forward. A new Kang would naturally have found his way there independently.
- Alioth is a being born from tears in spacetime, and it is apparently able to devour space and time. We can’t really speak to the thermodynamic plausibility of a higher-dimensional being such as this, so we’ll just have to accept that it exists.
- There is an End of Time. We can surmise that billions of years in the future, the spacetime fabric of the timeline perhaps decays, leaving behind some pocket of spacetime. Alioth surrounds the Citadel at the actual end of time, and pruned objects are sent just outside it for Alioth to devour. It is possible that the flow of time is somewhat unlinked from the flow of time at the TVA here.
- Loki is able to smell the deodorant of two separate Tony Starks at once.
From the above, we can glean the following about the actual chronodynamics of the MCU:
- Timelines branch and their variance can be measured.
- These branches can essentially be freely traversed as well as destroyed.
- At the end of time, at least one timeline decays into something of a Void.
- A spacetime creature called Alioth exists and it can devour space & time.
- When an object is “pruned”, a timeline can heal itself, possibly by drawing from the nearby Sacred Timeline.
To Be Continued…
There are a few outstanding questions left at this point:
- What happens to the timelines that branch off the Sacred Timeline but are not pruned? The TVA indicates that they are essentially reabsorbed into the Sacred Timeline, however we see no direct indication of this. It seems more plausible they exist in parallel, but the TVA never mentions them.
- How is variance measured? Is it a matter of specifically trying to prevent dangerous Kangs from existing? Are timelines allowed to exist because they are projected to generate friendly Kangs?
- How does a timeline heal itself from pruning?
- What is the chronology between the chaos at the TVA, Sylvie killing Kang, Loki transporting back to the TVA, and Kang reestablishing the TVA? We can speculate, but a lot of info is as yet unknown. There is a remote possibility that while the Sacred Timeline can branch, the TVA is completely overwritten–a dynamic timeline, operating on different rules.