Time travel has always been one of the pillars of the science fiction genre. Over the years, it’s only become more and more popular. Between Doctor Who, Outlander, Timeless, The Edge of Tomorrow, and more, pop culture has been full of varying styles. The world is now full of people slipping, falling, and adventuring through time. The most recent addition to the group is Avengers: Endgame, the superhero film to jump into tons of other films.
To keep people coming, time travel has quite a few common themes and rules across the genre. They may all be very different, but these similarities tie them together to create a sort of unspoken lore behind time travel that deviates depending on the material. However, they generally follow similar threads.
Endgame, though, has its own deviated version of time travel. Using a couple of the biggest, most common time travel principles, let’s see how it measures up.
Two Versions Of The Same Person Cannot Meet
This is one that almost every popular sci-fi time travel story adheres to. If the two versions of one person meet, either it will risk completely destroying the timeline (Back to The Future) or time itself will collapse (Doctor Who).
One of the few exceptions to this are in the Abrams Star Trek films, where “Spock Prime” meets Quinto’s Spock. However, this is explained with Trek’s multiple universes canon, saying that when Nero and Spock went back in time, they created a completely new and different timeline/universe. Therefore, old Spock meeting new Spock doesn’t affect his own past. Star Trek also breaks the rule with Janeway and Janeway in Voyager’s finale, but let’s not get too into those logistics because they don’t really make sense. Overall, it all just sounds complicated, doesn’t it? Welcome to time travel.
There are times the split universe concept is mentioned in Avengers to try to combat the amount of people who meet other versions of themselves. But that gives the disconcerting possibility that fans are just getting to see the universe where things go okay. Is this trying to say that there are millions of other universes out there now, fractured by their time jumping, that are desolated and broken because of it?
Regardless of split universe theory, right off the bat, this rule is one that Endgame doesn’t adhere to at all. Cap meets an old version of himself and they fight. Nebula meets an old version of herself, switches places in time, and then new Nebula destroys the older version of herself. They completely shirk this concept, so one would assume they’re just not following it at all. Time paradoxes aren’t a thing here, right? However, later, Cap goes back in time to replace the Infinity Stones and fix their time paradox problems. How would he fix these ones? No clue. Guess these don’t count.
Butterfly Effect/Fragility of The Time Continuum
The Butterfly Effect is the concept that a man could step on a butterfly in the past and completely change the future. Also, he could not, but the point is that everything could change. A time traveler may never know the impact even a tiny action they did could have on a timeline.
While some movies use it poorly (See: The Butterfly Effect), the effect of, say, missing a chance meeting that was supposed to change the rest of your life does completely rewrite a person’s history. They assume time is very fragile and could be rewritten by pure mistake.
Modern examples of this are the events of Harry Potter sequel The Cursed Child, “The Long Game” in Doctor Who (an otherwise anti-Butterfly show), and Until Dawn, a horror video game based on the effects of choice.
Avengers doesn’t seem to believe in the Butterfly effect, as nothing they’ve done in the past has affected the future. However, they don’t seem to have the Doctor Who philosophy that their time travel was always meant to be and time can’t be changed (most of the time). Their timeline isn’t rigid like that. Otherwise, Cap and others would have remembered their other selves visits. Also, they wouldn’t have been able to “change” history at all. They would have just done exactly what was supposed to happen. Ergo, their time travel rules seem to be in some indescribable middle ground.
A fair amount of time heavy stories have some sort of defense force or protective creatures that try to preserve the timeline. Anyone who watched Umbrella Academy saw this in their Temporal Commission that ensured the timeline stayed save with assassinations. Star Trek also has a similar group, The Department of Temporal Investigations, that exists outside of time to regulate people messing with it. And, of course, Doctor Who has those scary time harpies that erase people who try to change things.
Clearly, The Avengers don’t have that. At least, there are no signs of such an agency or group in Endgame. Though they completely played around with time and dragged a whole fleet of people from the past forward, no one has reared their head in disagreement.
However, to give the movie credit, that could be the plot of a different, future film.
Though there are even more, small rules that various time travel events use, these big three rules aren’t followed at all.
The easy gist is that the time travel in Avengers doesn’t really make sense. Time isn’t fragile nor rigid. They can meet older selves, or even kill them, no problem. However, there is no excuse of this being a split timeline like Abrams’ Star Trek. And if it is, it isn’t a manageable two-verse system but a multi-verse hell like DC. And any comic book fan knows how much awfulness can come out of multi-verse hell. Instead, we just have to assume killing Nebula in the past somehow doesn’t kill Nebula now. Does that make sense? Not really, but I suppose it does give her a fulfilling character arc of literally killing the person she used to be. And let’s not even get into the confusing nature of Peggy Carter, Steve Rogers, and time travel.
If there is a time travel police in this universe, the Avengers of the future will have A LOT of explaining to do.