Avengers: Endgame Spoilers

[Derek Metaltron]

They literally give us a PowerPoint lecture, from the guardian of the Time Stone and our green Avengers time travel guy, telling us you can close a branch. All that is needed is to put the stone back at the exact same time. (It probably doesn’t even matter where you put it, just the moment.)

I think this is the case, which means at this point I think the alternate 2012 timeline is the only one which couldn't be closed since the alternate Loki had the Tesseract, and also the alternate Sitwell and Rumlow would be assuming alternate Steve was HYDRA. Steve would be able to return the Time Stone to the Ancient One and presumably the Mind Stone in Loki's Scepter somewhere to SHIELD, but he wouldn't be able to reset things completely since doing so would have created a time paradox with the original Time Heist team.

The only other timeline one could imagine not being reset is the GOTG one since it would suddenly be absent Thanos and his armies, but I presume that Tony's Gauntlet undid all of the alternate Thanos' awareness of what had happened, so Steve could simply return the Power Stone for Star Lord to pick it up (assuming him being knocked out didn't have any issues - we also don't see Konath and his men arrive so we can't be sure if anything was changed with him and Ronan) and the Soul Stone to Volmir where he could hang out with his old pal Red Skull.

1970 SHIELD and 2013 Asgard weren't affected enough to change them, I assume. The only other question is whether Steve settled down in an alternate 1945 to the main one, since I assume doing so in the original would have had some major repercussions to history. I assumed he stayed until the alternate Peggy died and then returned to the main timeline sometime before Sam, Bucky and Bruce were expecting him back.

[JKtheMac]

Thanos and his who,e army being dead three years before Infinity Wars is not a “slight modification”. It’s a total time destroying paradox.

That’s why the seperate timelines need to continue existing. The Thanos that died when Tony snapped his gibngers was not our Thanos. He belonged to an alternate reality which continues on without him.

Effectively, Tony saved TWO universes

This is where your logic seems to be flawed. You seem to be suggesting the choices are 1: branches maintaining their existence or 2: branches being folded into each other. The movie shows us a third, branches being destroyed once the gems get placed back.

When Cap takes the Power and Soul Stones back to their respective timelines the Thanos branch, where he waits for Nebula to bring him through the ‘quantum tunnel’ will no longer exist. In the repaired timeline he isn’t dead because in that timeline he never travelled to the future. He will go onto the events of Infinity War.

[numberthirty]

Maybe Tony actually put back Thanos and his army to the time they came from (Time Stone and Space Stone) without memories of the future (mind stone) while making it look like they crumbled to dust for dramatic effect and because he is Tony Stark (reality stone)?

While this is strictly "Best Guess...", it feels like what you are saying is the "One" out of however many millions of possibilities that Dr. Strange was talking about.

By the time Tony is there and has heard Dr. Strange say "If I tell you, it won't happen.", he has enough brains to have worked out time travel along with all of the potential wrinkles.

He is a guy with the knowledge to actually use the assembled gauntlet to create a past/present/future that will not fold in on itself.

[JKtheMac]

I think this is the case, which means at this point I think the alternate 2012 timeline is the only one which couldn't be closed since the alternate Loki had the Tesseract, and also the alternate Sitwell and Rumlow would be assuming alternate Steve was HYDRA. Steve would be able to return the Time Stone to the Ancient One and presumably the Mind Stone in Loki's Scepter somewhere to SHIELD, but he wouldn't be able to reset things completely since doing so would have created a time paradox with the original Time Heist team.

The only other timeline one could imagine not being reset is the GOTG one since it would suddenly be absent Thanos and his armies, but I presume that Tony's Gauntlet undid all of the alternate Thanos' awareness of what had happened, so Steve could simply return the Power Stone for Star Lord to pick it up (assuming him being knocked out didn't have any issues - we also don't see Konath and his men arrive so we can't be sure if anything was changed with him and Ronan) and the Soul Stone to Volmir where he could hang out with his old pal Red Skull.

1970 SHIELD and 2013 Asgard weren't affected enough to change them, I assume. The only other question is whether Steve settled down in an alternate 1945 to the main one, since I assume doing so in the original would have had some major repercussions to history. I assumed he stayed until the alternate Peggy died and then returned to the main timeline sometime before Sam, Bucky and Bruce were expecting him back.

You can’t time travel with the Tesseract. So at the point we see Loki teleport away he will not have created a new branch. Now we know there will be a TV series so that may cover the journey he takes, and he may end up time-travelling, but so far we haven’t seen any evidence of him creating a new branch, just some potential time paradoxes. Reading between the lines of The Ancient One’s description of how the Time Stones create what we perceive as the flow of time, these paradoxes will probably be course corrected by events.

We also have nothing suggesting that Steve created an alternative universe. Indeed we are told such universes would be doomed to darkness. The fact he was just sitting off screen suggests he didn’t jump from another branch, he just lived his life parallel to his other self.

I agree we need to be aware that some things may have changed, and that somehow these things got smoothed out. For example, Loki presumably makes sure he is still arrested in the end, but may change things such that his death in Infinity War is only temporary.

[Keyotheseasons]

I just can't get over this moment.

[Derek Metaltron]

You can’t time travel with the Tesseract. So at the point we see Loki teleport away he will not have created a new branch. Now we know there will be a TV series so that may cover the journey he takes, and he may end up time-travelling, but so far we haven’t seen any evidence of him creating a new branch, just some potential time paradoxes, which reading between the lines of The Ancient One’s description of how the Time Stones create what we perceive as the flow of time, will probably be course corrected by events.

It doesn't matter though because the very action of history changing via 2012 Loki escaping with the Tesseract creates a new timeline. The alternate Ancient One might be able to find and stop her Loki but they wouldn't be able to reset things exactly as they should have been unless there's some major memory resets which stops all the Avengers and SHIELD from remembering that Loki escaped for a bit.

One of the fundamental rules of time travel in all fiction is if you see it, it happened and it can't be changed. Steve can't simply prevent Loki from escaping because Tony was present when it happened. It would create a major time paradox. I mean I could be wrong about the rules but I think the original Time Heist team created an alternate 2012 which cannot be corrected... probably. We'll see if Loki plays with it or not.

[numberthirty]

It doesn't matter though because the very action of history changing via 2012 Loki escaping with the Tesseract creates a new timeline. The alternate Ancient One might be able to find and stop her Loki but they wouldn't be able to reset things exactly as they should have been unless there's some major memory resets which stops all the Avengers and SHIELD from remembering that Loki escaped for a bit.

One of the fundamental rules of time travel in all fiction is if you see it, it happened and it can't be changed. Steve can't simply prevent Loki from escaping because Tony was present when it happened. It would create a major time paradox. I mean I could be wrong about the rules but I think the original Time Heist team created an alternate 2012 which cannot be corrected... probably. We'll see if Loki plays with it or not.

There is a simple "Trump Card" here that you aren't allowing for.

A fully assembled Infinity Gauntlet doesn't give a rip about your "Fundamental Rules Of Time Travel In All Fiction..."

[Somecrazyaussie]

You can’t time travel with the Tesseract. So at the point we see Loki teleport away he will not have created a new branch. Now we know there will be a TV series so that may cover the journey he takes, and he may end up time-travelling, but so far we haven’t seen any evidence of him creating a new branch, just some potential time paradoxes. Reading between the lines of The Ancient One’s description of how the Time Stones create what we perceive as the flow of time, these paradoxes will probably be course corrected by events.

We also have nothing suggesting that Steve created an alternative universe. Indeed we are told such universes would be doomed to darkness. The fact he was just sitting off screen suggests he didn’t jump from another branch, he just lived his life parallel to his other self.

I agree we need to be aware that some things may have changed, and that somehow these things got smoothed out. For example, Loki presumably makes sure he is still arrested in the end, but may change things such that his death in Infinity War is only temporary.

Yeah, he basically used the Tesseract to get away. Where? Well, only his series can answer that.

[Derek Metaltron]

There is a simple "Trump Card" here that you aren't allowing for.

A fully assembled Infinity Gauntlet doesn't give a rip about your "Fundamental Rules Of Time Travel In All Fiction..."

...except the Infinity Gauntlet can't affect anything not in your universe, that's been a fundamental rule in the comics for years. Though given the fact the stones were all from different possible timelines I suppose that's up to some debate. But even if he could remember Tony might not have been aware of the fact they had messed up the 2012 timeline, it seems like he only erased the major deviations of the 2014 timeline.

It's a headache I know, and we might never get answers. We shall have to see whether there is an alternate Loki and if he's either in his own 2012 universe or the main timeline now.

[Somecrazyaussie]

It doesn't matter though because the very action of history changing via 2012 Loki escaping with the Tesseract creates a new timeline. The alternate Ancient One might be able to find and stop her Loki but they wouldn't be able to reset things exactly as they should have been unless there's some major memory resets which stops all the Avengers and SHIELD from remembering that Loki escaped for a bit.

One of the fundamental rules of time travel in all fiction is if you see it, it happened and it can't be changed. Steve can't simply prevent Loki from escaping because Tony was present when it happened. It would create a major time paradox. I mean I could be wrong about the rules but I think the original Time Heist team created an alternate 2012 which cannot be corrected... probably. We'll see if Loki plays with it or not.

I don't think the fundamental rules apply here. Not in this case anyway. Which is why it has given me a severe headache. But thanks to JKtheMac, I have finally got my head around it. I think its why they bring up Back To The Future so much. They are taking pains to contrast its rules (which is one of the most famous cases of time travel in fiction) with those presented in Endgame and basically say, "Well, that's not how it works!"

[JKtheMac]

It doesn't matter though because the very action of history changing via 2012 Loki escaping with the Tesseract creates a new timeline. The alternate Ancient One might be able to find and stop her Loki but they wouldn't be able to reset things exactly as they should have been unless there's some major memory resets which stops all the Avengers and SHIELD from remembering that Loki escaped for a bit.

One of the fundamental rules of time travel in all fiction is if you see it, it happened and it can't be changed. Steve can't simply prevent Loki from escaping because Tony was present when it happened. It would create a major time paradox. I mean I could be wrong about the rules but I think the original Time Heist team created an alternate 2012 which cannot be corrected... probably. We'll see if Loki plays with it or not.

I am not convinced. The movie never categorically says you are wrong, but the way it tells us the rules suggests that Banner was wrong. That time doesn’t branch just because some details change. That paradoxes are avoided by the action of the stones working in concert. That Steve can live a life in the same universe as his frozen self without branching time. It’s what the movie seems to be telling us.

[Vworp Vworp]

I guess Black Widow’s solo movie is going to be a prequel.

Not necessarily. It's not like comic book Tasha hasn't died a few times.

Fingers crossed. It'll be easier to accept Tasha's fate in this movie if it's ultimately fixed. Otherwise though, and a few days after the initial overwhelming buzz of seeing Endgame, Tasha's underwhelming death is already starting to mute my overall enjoyment of the movie.

[Derek Metaltron]

I don't think the fundamental rules apply here. Not in this case anyway. Which is why it has given me a severe headache. But thanks to JKtheMac, I have finally got my head around it. I think its why they bring up Back To The Future so much. They are taking pains to contrast its rules (which is one of the most famous cases of time travel in fiction) with those presented in Endgame and basically say, "Well, that's not how it works!"

Agreed, though the problem is they don't really do enough to explain why it's different to BTTF rules, likely because they don't want audiences to focus on it too much like we do.

Fundamentally though and going by what the Ancient One said, I assume it this way: If you get everything back to the way it was properly with minimum fuss, history corrects itself fine.

Example: in the Asgard 2013 timeline Thor and Rocket take the Reality Stone out of Jane and Thor's hammer and Steve brings it all back (not sure how easy with Jane that would be have been but hey ho). Freya presumably figures out she's going to die but accepts it. Ergo history doesn't change.

If however you can't get things back to the way things were, this instead creates an alternate timeline where history branches off. This happened I think in 2012 because there was no way of really restoring the Space Stone/Tesseract to where it had been after Loki took it and escaped. Ergo there's now an alternate 2012 in play.

That's how I understand the rules of time travel and alternate universes in the MCU. It's likely there are naturally occurring alternate universes as there are in the comics (which will be explored in the What If series) but the 2012 timeline is an artificially created one via time travel.

[cc008]

Bucky is White Wolf in the MCU, so Sam was the only logical choice.

Once again it has NOTHING to do with who became Cap.

I just wanted more Steve and Bucky interaction because I felt like their relationship is stronger than Steve's and Sam's. And was portrayed that way throughout the films.

[JKtheMac]

There is a simple "Trump Card" here that you aren't allowing for.

A fully assembled Infinity Gauntlet doesn't give a rip about your "Fundamental Rules Of Time Travel In All Fiction..."

This is also true. The way this movie suggests that time works is as a mysterious and mystical thing. It isn’t fully in the realm of science. It is governed by these six strange stones with weird and not fully explored powers. I believe Thanos’ plan to use the stones to create a brand new universe where everyone is happy to have half the population would have been perfectly OK as far as the mystical rules are concerned. I don’t believe for one second that the stones are destroyable. But they probably recombine somewhere else.

Outside of movies there are plenty of time-travel stories that use self correcting time. It’s not that uncommon in TV either, because it helps maintain continuity. This movie creates a relatively secular way of suggesting how this might work, even if it is a little mystical. It allows for the world of Doctor Strange to sit beside the scientific world.