Here’s another idea…
Maybe the characters can both change time and create alternative realities!
So we know that photos and newspapers can change and Marty can begin to disappear. So this could be seen as proof that their timeline was changing.
But what if as well as changing the timeline they are in, they are also creating alternative timelines and realities? Maybe you can change the future of set events of a timeline if you are in it, but the problem comes for you when travelling in time itself.
We know that Marty and Doc didn’t experience 2015 becoming a future of the Powerful Biff timeline whilst they were in it. Doc only gave the theory that if they tried to return to 2015 it would be the future of the Powerful Biff timeline. This is theory which wasn’t tested.
We can question how old Biff was able to travel from 1955 back to 2015 to leave the time machine for Doc and Marty without himself arriving in the Powerful Biff timeline. We know the ripples in time can change slowly or fast and this may have been that he slipped through a glitch in the fabric of the space time continuum.
But maybe the thing that takes you into an alternative reality is the time machine itself. The DeLorean as far as we know it is just a time machine, but maybe the Doc created a device that could cross the Rosen Einstein Bridge without realising it. This would explain so much…but this is purely theory and there is no evidence to confirm this other than that Doc acknowledges alternate realities.
But What About The Jennifer Marty Left On the Porch In The Powerful Biff Timeline?
OK so now this is where things could start to fall apart for this whole theory!
When Marty and Doc arrive in the Powerful Biff timeline Marty leaves Jennifer on the porch bench outside her house. He comments that he didn’t remember there being bars on the windows of her house. Marty and Doc then end up going back in time to 1955 to try to prevent the Powerful Biff timeline from happening. Fom there both Doc and Marty go back in time to 1885, before finally Marty comes back to what we can view at the Good 1985 at the end of Back to the Future Part 3.
Upon arriving in the Good 1985 Marty finds Jennifer on the porch bench outside her house where he had left her in the Powerful Biff timeline, but now it is her original house and there are no bars there.
Surely if she is still there it can be argued that time is in fact changing around her and they are not in an alternative reality. Right?
Maybe not.
Just because Marty finds Jennifer on this bench it doesn’t mean she is the same Jennifer that was left there by this Marty in the Powerful Biff timeline. This could be another alternative Jennifer who had a very similar experience to the one we saw in the Part 2.
Isn’t this a stretch?
Yes!
Why?
Jennifer sleeping on a bench isn’t enough evidence that she is the same one that Marty left in the Powerful Biff timeline, and that this is therefore the same Good 1985 timeline that Marty, Doc and Jennifer had left at the end of Part 1.
But what is more compelling evidence is that she was able to describe the things that we (the audience) saw happen to her in Part 2. She also had the fax which said that Marty had been fired from his job as we witnessed happen in Part 2. Further to this we see that the message of ‘You’re Fired’ disappeared as she opened it which suggested that time was still changing.
Why would it change when she opens it?
Good question!
These changes such as the fax, or the photo of Marty’s siblings, newspaper of George being murdered etc should in theory all change instantaneously and blip out of existence if they never existed in their previous form. We see this happen to the newspaper cuttings of Doc being comitted and George’s murder. As soon as time was changed, the objects changed. However it can be noted thath these changes actually only happened when a character viewed them. This could play into the idea of whether a tree falling in an empty forest makes any sound. These changes only occur in time when observed by someone.
It could be argued that maybe these changes are mostly for the audience to see the changes. This is probably true, but in the case of Marty’s siblings and the photo of the gravestone in Part 3, the changes are slow as mentioned earlier. This tells us that within the franchise the rules of time changes work on a ripple effect and aren’t always instant.
But hang on, coming back to Jennifer a moment…
If the Jennifer found on the porch in the Good 1985 was the same Jennifer left on the porch in the Powerful Biff 1985 wouldn’t that mean that time has just morphed around her?
Yes it would and this would be a big indicator that time can change and alternative realities can be erased. This would play into the idea that time has a roughly intended destiny and was able to be healed or repaired or fixed back to what was the Good 1985 timeline.
Perhaps to go down the route of Quantum Leap, it could be a thought that maybe the Good 1985 timeline was always supposed to happen and the events of Back to the Future Part 1 was Marty putting right what once went wrong.
Is there an alternative to this?
Of course.
The alternative explanation is that one version of Marty dropped a version of Jennifer off in the Powerful Biff timeline having arrived in the past from 2015, and another Marty dopped another version of Jennifer off in the Good timeline. This is a stretch, but not when you consider that the idea of a multiverse is that every eventuality can be played out. It would just be lucky that Marty ended up in another reality which was like the Good timeline, but also had a version of Jennifer who was nearly identical to the one he left in the Powerful Biff timeline.
The fact is that the Jennifer that we see at the end of Part 3 doesn’t have any knowledge of the Powerful Biff 1985 timeline as she slept throughout it. This means she cannot confirm or deny that she was ever in the Powerful Biff timeline.
