Do not read any further if you haven’t seen Source Code and do not take this post as reason to go see Source Code because the end is a little confusing. I just want to get my thoughts out about what I think happened at the end of the movie which I think deals with the possibility of an alternate universe.
Okay so basically Colter’s consciousness is turned into source code and plugged into the source code of the last eight minutes of Sean. He goes through a few strings or alternate realities as Sean and saves the day. The second last string where he communicates with the “real world” he tells Goodwin who the bad guy is and authorities arrest him and the dirty bomb that was going to blow up Chicago doesn’t. However in the “real world” all the passengers on the train die.
Still in the “real world” Colter convinces Goodwin to send him into the loop again and to pull the plug on his life support in the real world when his 8 minutes are up. Now in the “alternate world” Colter saves the train, gets Russell Peters to make everyone laugh, gets the girl and sends an email to Goodwin detailing the power of the Source Code. At the same time, in the “real world” Goodwin has pulled the plug on Coulter and he has died. Now in the “alternate universe” Colter got the ending he wanted between 7:48 am and 7:56 am on the day the terrorist attack was to take place. So when Goodwin comes to work at 8:30 am she receives Colter’s email because they are in an alternate universe. At that point many may falsely think we are back in the “real world” and Colter has communicated from the “alternate universe” to the real world.
So why is it an alternate universe?
(1) The guy who created it, specifically said it’s not a simulation. If it’s not a simulation than it has to be really happening somewhere, meaning the scientist has figured out a way to plug this reality into multiple realities in 8 minutes intervals.
(2) When Colter is “lost” between realities, the scientist says “wait till he finds another string”. Each time, Colter died he was in a different string and when he died or his 8 minutes was up, he was brought back to a certain string, we’d call the “real world”.
(3) In the last alternate reality, Colter calls his dad and talks to him. If this we’re just Colter reliving Sean’s memories, there is no way Sean would have an understanding of Colter’s relationship with his dad in order to even have a conversation with his father. He also wouldn’t be able to track the terrorist’s van down and get his licence plate or open his wallet since Sean never did that in the “real world”. But Colter could in the “alternate world” because it is just as real as the “real world”.
(4) In Colter’s email to Goodwin where he says the source code is more powerful than the scientist thought it is because he was able to stay in an “alternate reality” for longer than 8 minutes, likely because he died in the “real world” when his life support was turned off and assumed the body of Sean. Colter confirms this with the email to Goodwin stating, “If you’re reading this e-mail, then Source Code works even better than you and Dr. Rutledge imagined. You thought you were creating 8 minutes of a past event, but you’re not. You’ve created a whole new world. Goodwin, if I’m right, somewhere at the Source Code facility, you have a Capt. Colter Stevens waiting to send on a mission. Promise me you’ll help him. And when you do, do me a favor: tell him everything is gonna be okay.”
Now while this alternate reality theory I have presented does make sense to me, what may seem a little shaky is if Colter has assumed the body of Sean in the alternate reality than whose consciousness is in the half dead Colter in the Source Code facility? The most obvious explanation I can come up with is that is the half dead Colter has the consciousness of the Colter that existed before the “real world’ consciousness of Colter came into this alternate reality. Therefore, Colter has two separate consciousness living in the same reality, which maybe a problem for quantum physicists, but not for a science fiction movie.