Avengers Endgame is out now and it involves time travel. The time travel in Avengers Endgame is quite different then most of the Hollywood movies. Before you proceed forward to read the article, we must tell you that it contains huge spoilers. So if you haven’t watched the movie yet, please come back after watching the Endgame.
Time travel has only happened in the movies so far, not in reality. And when it comes to the movies we have seen three basic theories or assumptions about time travel.
First one is where changing anything in past will change the future. It is the most flawed and baseless theory used by most of the Hollywood movies. To explain why this theory is absurd, consider the famous “Grandfather Paradox” in which a hypothetical person travels back in time and hypothetically kills his own grandfather, which would definitely kill this person himself because his grandfather is dead. But if that person is dead, then he won’t be able to go back in time and kill his grandfather in the first place too. That’s why Professor Hulk tells us that time travel doesn’t work like in the movies. It’s great to see Marvel is finally bringing some different and close to real science to Hollywood.
Second one is where future is immutable, no matter what happens in past, it does not change the future. It means your past actions has already shaped the future. And even if you go back in time, it was meant to happen to reshape the future you already have. So basically it is sort of a fixed time loop where whoever travels back in time know exactly what they must do in the past because it’s already happened in the future.
And finally the third theory is about parallel universes or timelines. It means when you go back in time and make some changes, you create a divergent timeline. This new branching timeline is a result of the changes you made to the original timeline. Your changes are taking place in a new timeline, and original timeline is moving on as it is with no changes. In simpler words changing something in past will create a whole new universe and a new timeline from that point. This theory may be false but still is the most logical science fiction time travel theory with minimum loopholes.
Now the time travel in Avengers Endgame is closely based on third theory. Which means changing the past won’t just magically change the future, instead it will create a divergent timeline. As Professor Hulk said “If you travel to the past, that past becomes your future and your former present becomes the past which can’t now be changed by your new future.” It is based on the popular quantum physics time travel “Multiverse Theory” and Ironman in fact mentions the name of the guy who came up with it, that is “David Deutsch”. Avengers Endgame narrowed this theory further down and made it a bit more simpler, in MCU a timeline or as the ancient one calls it “reality” is formed with the help of Infinity Stones. In other words, a branch reality can split off of the main reality if an Infinity Stone is removed from it and not replaced. That is the reason why Bruce Banner told the ancient one that “we can return each one to its own timeline the moment it was taken so, chronologically, in that reality, it never left”. As long as all Infinity Stones exist in the same time (regardless of their location or being spread across the entire universe), they create that specific single reality.
So how many realities were formed when stones were removed?
May be 6, each for one infinity stone or 7 (if we consider space stone removal twice because one was removed by Loki), but we will consider the ones that matters in Avengers Endgame and aggregate the similar ones. In order to understand this, let’s consider the following image.
Now we know how many timelines there are. The New York timeline is formed at the time of the first Avengers movie from where Time stone and Mind stone are removed in 2012. A new Loki timeline is formed from New York timeline since he took the space stone and disappeared (we can safely say that this whole new timeline will be explored by Loki in his upcoming Disney+ show). The military base timeline is created again from the New York timeline, when Rogers and Stark both went back to the time of Peggy and Howard to retrieve the Space stone again. In the same way, Asgard timeline is formed when Thor and Rocket removes the Reality stone from Asgard. And finally the Morag timeline is formed when Hawkeye and Black Widow retrieve the Soul stone, and War Machine gets the Power Stone.
So if Thanos is turned to dust at the end of Endgame, the snap never happened in Infinity War as older version of Thanos is dead now?
During final battle the Thanos version of 2014 is dead, but not the one who actually did the snap to main timeline. The Thanos of the main timeline was killed at the beginning of the movie. This 2014 version of Thanos is from another Morag timeline, where he actually didn’t collected the stones yet. So killing this version of Thanos means that now Morag timeline is also saved from his evil actions. Remember Thanos travelled from newly created Morag timeline to main timeline in order to get all the infinity stones at once.
So how Gamora is alive now and why Nebula didn’t die when she killed her past version?
Well it’s pretty clear now that Gamora is from Morag timeline, the Gamora of original main timeline is still dead (she isn’t returned back even after undoing the snap as she was traded for the Soul stone). And Nebula of main timeline killed the Nebula of Morag timeline, so technically she didn’t killed her past version. She killed an evil past version of another timeline.
So at the end when Captain America returned all the stones, are those newly created timelines erased as well?
No, they still exist. Captain returned the stones to the newly created timelines, not in past of the original timeline, since Professor hulk explained that you can’t change the past. When Avengers took the stones, they created new timelines and at the end they just returned the stones to their newly formed timelines in order to keep the timeline intact and to protect those timelines from the dangers to come (as Ancient one said they need time stone in new reality as well to protect themselves from dark forces). Avengers didn’t need to return the stones because it never threatens their own timeline, but they did that because they also wanted other newly created timelines to be safe. That’s the promise Bruce made to the Ancient One.
So how did at the end Captain America did not created another timeline when he decided to stay with Peggy?
Well there are two theories here. First one is more believable that Captain never created the new timeline. He was always the husband of Peggy Carter. His older version went back to the Peggy while his younger version still comes out of the ice and joins the Avengers and fights for earth. He just managed to stay away from his younger version and Peggy kept it a secret. That’s why Peggy never mentions the name of her husband when Steve visits her in the Winter Soldier movie.
Another theory is, Steve might have created a new timeline but he just came back when becomes very old to to main timeline at the end of the movie using the device Stark gave him just to hand over the mantle of Captain America to Falcon. But that’s highly unlikely since Steve never removed any infinity stone which could cause another timeline to be created according to Ancient one.
What actually time stone does? Does it create a new timeline everytime when someone uses it?
One can think that in MCU the time stone is also somewhat manipulating time, so it means that everytime when someone uses a time stone, it also creates a new timeline. Wrong, time stone is very different, it allows you to slide through time, not jump through time or change it. When Doctor Strange looked up to 14 million outcomes in Infinity War, he was just sliding through different scenarios and seeing which one is the best. He did not changed anything, instead he made sure that one particular is followed by letting Tony Stark live.
Well that’s our take on how time travel happened in Avengers Endgame. And it is different from most of the movies but yes we can it is more closer to science. Let us in comments what you think of it.