One eagle-eyed Reddit user may have casually cracked an important code in the Marvel Cinematic Universe. u/Redditman-101 recently posted about something he noticed in an important Avengers: Endgame moment that everyone else seems to have missed. If he’s right, the ramifications in the overarching MCU could be enormous.
The moment occurs when Bruce Banner, Steve Rogers, Natasha Romanoff, and Scott Lang are doing time travel tests at the Avengers Compound. Banner tells Lang that he’s going to send him back in time one week, let him walk around for an hour, and then bring him back; however, when Lang returns, he’s a teenage boy. As Banner fiddles with the controls, Lang hops in and out of time, returning as an old man, a baby, and finally his regular adult self. As Tony Stark points out moments later, they tried to make Scott pass through time only to have time pass through Scott, a result of what Stark calls the EPR Paradox.
The scene’s humor makes u/Redditman-101’s discovery an easy moment to miss, especially since Stark arrives at the Compound armed with new fully-functioning time-space GPS gadgets. As the user points out in his post, Lang retains all of his memories from the test, even when he returned to the present as a baby. His consciousness remained intact even though his body and age changed, which means that Banner and company might have unintentionally found the answer to human immortality.
Because the moment is so quick, and because Stark’s arrival with the new time-travel devices inspires the Avengers to round up the rest of the team and proceed with the time heist, this discovery gets pushed aside for the rest of the film (and so far, all the ones since). It may not have even reached the point of consciousness for anyone on the team except perhaps Banner, who could theoretically be saving this discovery for a useful future point in time.
As u/Redditman-101 says in his post, “There is a species of jellyfish in the Pacific Ocean that is able to revert back into a pupae once they grow too old. This species of jellyfish is effectively immortal. And Bruce, Steve, Natasha just did this to a human being while messing with time itself.”
This effectively means that if a character in the future MCU wants to live forever, all he or she has to do is hop inside the time travel suit and have Banner (or an equally adept ally on controls) turn back their physical clock.
As one user alludes in the comments, a potential problem with this theory lies in the complication of having an adult heart in a younger person’s body⏤unless this particular kind of time travel essentially resets the full physical body (including vital organs) without affecting consciousness. If this is how this version of “time travel” really works, then depending on the character who tries to attempt it, it could have either devastating or highly useful consequences.
Whether future Avengers or their enemies will make such an attempt at immortality remains to be seen, though it seems unlikely since the MCU would then run the risk of overtaxing the time travel convention. Then again, we never quite know what to expect in the MCU, and like so many other Easter eggs that have been planted in the films for us to find, this could prove to be a crucial one down the line.