One of the most celebrated and heavily criticized trilogies in film is the Back to the Future Trilogy. I think this trilogy was probably the first time I thought that the second two films were totally not necessary. It was, after all, supposed to be one film that had an open ending. But after the smash success of the 1985 film, it was only natural that Hollywood would make a cash grab and make two more films. That’s how things worked (and still do). That said, I actually did enjoy parts 2 and 3. They weren’t terrible films, but they are certainly nowhere as good as the first.
Common criticisms of 2 and 3 include:
- Part 2 didn’t spend enough time in the future, and took us to an era we’d already been (the exact setting of the first movie).
- The 2015 we see in the film is too advanced.
- Marty’s sudden aversion to being called a chicken, to the point that he completely loses it whenever he is called one. This was nowhere to be seen in the first film, and it feels so unnatural when they introduce it in the second for a payoff in the third.
- They couldn’t get all members of the original cast. Marty’s girlfriend Jennifer is played by Elisabeth Shue instead of Claudia Wells, and Crispin Glover, erm, I mean George McFly is played by Jeffrey Weissman.
- Common time travel plot holes and paradoxes. (It makes no sense that Biff could return to the 2015 he left).
- Jennifer Parker didn’t do anything in 2 and 3 other than sleep. This was a wasted opportunity.
But are these really problems? Well, story wise, the only ones that are problems that detract from the overall quality of the films are 1,3 and 6. The other problems don’t really disrupt the story, they just bother nitpickers and fridge logicians. Let’s address the first criticism before discussing the logic of time travel.
The criticism that the second movie didn’t spend enough time in the future and took us right back to the setting of the first film is not invalid. It’s been a whole 5 years and we’ve been anticipating going to 2015 ever since the end of the first film! But…
But nothing! We’re going back to 1955 again. Didn’t we already go there? Why are we going back? We just saw this!
I’ll remind you again that the second film came out a whole 5 years after the first. That’s a considerably long time between a film and a sequel. While it was certainly possible to rent or buy the first film on VHS, the scenes of the first film were likely not as fresh as they would be to the bingewatcher of today. In 1990, the average filmgoer didn’t see the third act of the first film right before seeing the second film.. When I saw part 2 in the theatre in 1990, the first thing I did when I got home was to watch the first film again and see if I could spot Marty from Back to the Future 2 anywhere. Of course I couldn’t, because the filmmakers hadn’t written the plot of Back to the Future 2 when they shot the first film. But the point is, I was very intrigued by this, and I thought it was kind of awesome. Now, to some, it might have been more fun to have gone to the 1960s or 1970s, and while I think that would have also been neat, having Marty 2 solve his own problems while simultaneously trying not to disrupt Marty 1 makes a really awesome story (and jumpstarts deep thought about the logic of time travel in young impressionable viewers.) Therefore, I don’t think this is much of a problem.
Let’s talk about time travel theories already!
Fair enough. Before we go on, I have to mention where I get most of my understanding of time travel from. I believe in a linear expression of time where everything remains normal from the beginning of time (point A) to the point in history where the first ever journey into the past occurs (point B). Then from the point the time traveler travels back to (point C) and onward replaces the corresponding area in the first timeline completely.

These are the three possible outcomes of time travel. Courtesy mjyoung.net
While I did independently think of some of these time travel theories, no one author has summed up my exact thoughts (and taught me more) on the logic of time travel as M. Joseph Young. There are countless time travel stories where the logic simply makes no sense (examples: Time Cop, Looper, Star Trek: First Contact, Superman etc…). When I found MJ Young’s blog, I felt as if finally I had found someone who felt the same way I did on time travel, and he has succinctly and completely laid out the theories in ways that I never could. So special thanks to MJ Young. It is from him that I learned of logical terms like the N-jump, the infinity loop (or causality loop), and the Sawtooth Snap… and trying to avoid making an infinity loop should be the objective of any traveler who accidentally finds himself in the past. The importance of this exceeds that of “righting the wrongs of history.”
That said, let us return to Back to the Future. I will attempt to address all of the criticisms with time travel explanations when possible.
Since we’ve just discussed the logic of time travel, it is still possible to make a good time travel movie even with faulty logic. For example, in part 1, it makes no sense that Marty’s photograph of him and his siblings can begin to fade from existence once he interrupts his parent’s first meeting. Instead what would have happened is that he he would create an infinity loop wherein he erases his existence, making it impossible to interrupt their first meeting, meaning he would have been born, meaning that he could interrupt their first meeting… When we talk about the common plot holes in time travel stories (as we have above), there are some that we have to suspend our disbelief for (as I mentioned). Had Marty undone the fabric of the universe in this way, the movie would have been cut abruptly short when his dad fell out of the tree and he pushed him out of the way of Grandpa’s car. That doesn’t make a fun movie. The disappearing photograph also makes no sense. Fading Marty doesn’t either. But these neat ideas in the first film that are cute even if illogical.
Get on with it! Come on! We get it! We have to suspend disbelief, but if I want to nitpick, then you can’t simply explain away things by saying it’s to make the movie better. We know that. We want a real explanation…
Is 2015 as portrayed in Back to the Future 2 too advanced? Well, considering that 2015 is now in the rearview mirror and as of this writing we don’t have flying cars, hoverboards, self-lacing shoes, self-drying jackets, dehydrated, rehydratable food and other amazing technology that we see in the film, this sounds like a resounding yes. But we have to consider that from a moviemaking perspective, going to the far off year of 2015 and having it be not that much more advanced than 1985 would have been anticlimactic. We’ve been waiting to see 2015 for five whole years. It would have been a huge letdown to see the actual 2015, though we might have thought the funky smartphone devices were neat.
But there could be an in-universe explanation for the much more advanced technology. We have to consider that this is a time travel film, and it is very possible that the 8 time travelers we see are not the only 8 beings to have ever traveled to the past and influenced the present and future. (Yes there are eight. Einstein, Marty, Doc Brown, Jennifer Parker, Biff Tannen, Clara Clayton, Jules Brown, Vern Brown). Given that in the 2015 presented in the second film it appears that Japan’s bubble economy has continued well into the 2010s and shows no sign of stopping, it is highly likely that a Japanese corporation has also independently discovered or reverse-engineered time travel, possibly traveling forward, plucking pieces of tech from the future and bringing them to the past or present. This would thereby accelerate the rate at which technology develops, meaning that it might be more accurate to say that the 2015 we see in Back to the Future 2 is in fact not advanced enough.
I’ve always felt that once a time machine is built, unless the traveler(s) are extremely secretive, it is as if infinite time machines are built and technological singularity or a broken universe are the only plausible outcomes. But let’s say that this other traveler we haven’t seen is also careful and secretive.. and wants only to avoid the lost decade of the 1990s in Japan. Fine. She may simply have altered the timeline so that technology evolves faster than in our own reality.
Nobody really complains about the level of tech in 2015 though, we knew it was a “quasi futuristic” setting. I want to know why Marty inexplicably can’t stand being called a Chicken.
Alright…Let’s move on to more important charges against the second and third films. Marty suddenly can’t stand being called a chicken in Back to the Future 2 and 3. They invented this tragic character flaw in order to show growth in his character at the end of the third film, but this wasn’t introduced in the first film, so it feels hokey and kind of rushed. I felt like it made no sense the first time I saw it, but again, since this is a time travel movie, there COULD be an in-universe explanation for this.
The Marty we are watching in Back to the Future 2 and 3 is NOT the same Marty from Back to the Future 1. If your recall the ending to the first film, Marty’s parents are more successful because of his actions in 1955. This would mean that Marty would have been raised by these more successful parents rather than the ones we see in the beginning of the film, the office lackey Dad and the alcoholic Mom. Perhaps Marty 2 (we’ll call him Marty 2, but he may in fact be Marty 5 or 6 or 37 depending on how many sawteeth there were) was raised by the George McFly who remembers punching out the bully, and was taught to stand up for himself. THIS is what causes him to throw down whenever anyone calls him names. Perhaps there’s another reason, but the point is that this Marty’s life experiences are vastly different than the Marty who first travelled to the past and experienced the original AB timeline.
Okay, well if this is a different Marty who looks the same, why are we supposed to think that Elisabeth Shue is the same Jennifer who looks different?
To address the next nitpick, while it is unfortunate that Claudia Wells and Crispin Glover could not agree to terms to return to the franchise, it isn’t that detrimental to the story that they are played by different actors. In fact, I don’t think I realized that they were both replaced until years later. (Remember, I was a kid at the time.) But we could make an in-universe explanation for both characters’ altered appearances. Let us first consider Jennifer. She’s played by Claudia Wells in the first film, but in the second she’s played by Elisabeth Shue.
It may be that Jennifer 2 (or 5 or 6 or 37) has a different genetic makeup than Jennifer 1. When we are talking about time travel, it is entirely possible that changing circumstances in the past could change the very genepool in the present or future. If a person’s parents don’t procreate with each other at the exact time in the exact same way that they did in a previous timeline, it is highly likely that their child would be of a different genetic makeup, resulting from their being conceived via a different sperm and different egg. (See the film About Time for more on this). So Elisabeth Shue Jennifer is not the exact same person as Claudia Wells Jennifer. They may not even have the same parents. It’s certainly possible that with all this jumping backward in time that Marty and Doc interrupted the first meeting of Jennifer’s parents. In the best case scenario Claudia Wells Jennifer and Elisabeth Shue Jennifer would be genetic sisters. But since we know that in these stories, the earliest date that travelers have gone to is 1885, it is also possible that these two Jennifers would be distant cousins (as far as DNA is concerned.) How related they are isn’t important though. The point is, they are different people, and their differing appearances can be explained due to time travel.
But Marty didn’t interfere with Jennifer’s parents at all after his first trip to 1955! Claudia Wells is in the ending of the first movie!
Correct. We DO know that Marty’s original trip to 1955 and back did not alter her genetic makeup (or at least not to a great extent) because Claudia Wells is present in the end of Back to the Future 1. This only indicates that the change occurred in a subsequent run-through of the timeline caused by a subsequent trip to the past. Perhaps this was the result of Marty’s second trip to 1955, or maybe Doc’s trip to 1885, or the trip of some other traveler we don’t know about. What we do know is that in the beginning of part 2, we’re not watching the first run-through of the timeline since Marty’s been back from 1955, whereas in part 1 we are (or we are at least watching an earlier run-through, depending on which timeline the DNA change occurred.) This only further corroborates the idea that we could be watching a different Marty in the second film than we were in the first. If time travel can make Claudia Wells turn into Elisabeth Shue, surely it can make Marty’s personality different.
When discussing George McFly, we can apply similar principles to explain why he was played by a different actor. It’s not really that important to do this, though. Besides, the actor had prosthetics applied so that he could look like Glover, and this ended up changing laws about one’s likeness being used in film, so it was very much intended to be Crispin Glover. But if you don’t like that idea, then apply the same explanation and we’ll say that Marty’s interactions with Sheamus McFly in 1885 changed George’s appearance somehow.
Okay then smartypants, explain how it is possible for Biff to go to 1955 to give his younger self the almanac, but still return to the 2015 we are watching. Why weren’t the changes to the timeline instantaneous?
We’re getting really deep into the nitpicks here, but yes. this is something that has always bothered me about this film. If Biff stole the time machine in 2015 with the intention of going to 1955 and giving his younger self the sports almanac, then it makes absolutely no sense that he could return to the same 2015 we are watching (even though the story demands this so that Marty, Doc and Jennifer can get back into the DeLorean). If Biff’s actions caused (what Doc Brown calls) 1985 A to occur, then he’d have to return to 2015 A. We can only conclude that Biff was unsuccessful in his first run, and changed nothing, if not very little.
Well, but the movie shows that 1985 A happened, so he couldn’t have been unsuccessful.
Yes, it happened, but since Biff was able to deliver the DeLorean back to the 2015 we’re seeing in the film, Biff himself was not successful, but Marty and Doc caused him to be successful somehow during their immediate trip back to 1985 (which happens to be 1985A).
What? Doc and Marty can influence 1955 by going to 1985?
Here’s where it gets complicated. No, they can’t influence 1955 by going to 1985. They would have had to first take a trip to 1955, then forward to 1985.
That didn’t happen in the movie!
Well, we don’t see that happening, but it is certainly possible that they didn’t readjust the time circuits from Biff’s trip and accidentally returned to 1955, inadvertently caused young Biff to get the almanac, then moved forward to 1985A. We also have to assume this didn’t happen on screen.
Huh?
Alright, I’ll try to lay it out for you. If we have to start with an A-B segment (even though it may be the Y-Z segment considering what happened in the first film) for the purposes of this reconstruction, the A-B segment starts at the beginning of the 2nd movie. (Though logically moving them forward from 1985 means that at least in the first time they go to 2015, their older selves and children shouldn’t be there, unless it’s a subsequent run through of the timeline, but again, for the purposes of this exercise, we’re calling A-B the version of events that we see in the 2nd film.) Keep in mind this is only one possible way to accomplish what we see in the film, and there could be others.
- A-B) Doc returns from 2015 to 1985 to bring Marty and Jennifer forward so they can deal with a problem with their kids. While in 2015, Biff steals the time machine so that he can return to 1955 and give his younger self the almanac.
- C-D) Biff fails for some reason. Either he has a change of heart or he hands the almanac over to young Biff, who loses the it for whatever reason. We don’t see this occur, but Biff returns to 2015 without having changed very much in the past.
- E-F) Doc, Marty and Jennifer return to the past, making the mistake of traveling first to 1955. They may be there for only a few seconds, but as a result of their actions, Biff’s plan from C-D is now successful. (Perhaps Old Biff in 1955 sees the other DeLorean and this causes him to not have a change in heart. Perhaps young Biff sees the DeLorean and now believes what the Old Man had to say. Whatever the reason, Biff becomes rich because of the almanac and it’s Marty and Doc’s fault). Marty and Doc now travel forward to 1985, and it’s 1985A. They realize that the past has been changed and assume that they have to go back to 1955 and get the Almanac.
But wait, if they caused 1985A, then how would there even be a time machine at all? Emmitt Brown is put in a mental hospital in 1985A. Also what happens to 1985A’s Marty, who was said to be in boarding school in Europe? Wouldn’t that erase the entire first movie since a time machine would never have been built in the first place?
In short, yes. The movie is beyond broken if we use the theory we’ve been operating on up to this point. But one way to look at time travel is that it is possible to have experienced something in a previous timeline and have memory of it in a different one. (Or for objects to originate in a previous one and still exist in a subsequent one). If this is an N jump, for example, something you’ve created in AB can still exist in CD even if it wasn’t created in CD. (Though that also means that if it wasn’t created in CD then it couldn’t exist in EF, but the AB version of it could… maybe). We’ll have to agree that this is at least how these films operate. Marty in BTTF 1 is surprised when he comes back from 1955 because his brother and sister and parents are all different and he has a new truck that he didn’t have before. He clearly has memories from AB. So… to answer your question, if in 1985 Doc invents a time machine, then in 1985 A it’s still possible that he has his 1985 time machine. Rather than N Jumping, just lay the segments back to back, (example.. someone born in 1955 who in 1985 travels back to 1955 and “takes the long way” back to 1985 would be 60 years old and have memories of both timelines, having experienced both.)
Okay, but. Time either works one way (your theory) or another (the film’s theory). It can’t be both.
Yes, and that’s where you have to suspend your disbelief for the sake of the film watching experience. Let’s just say that in this instance it works, and the film is able to continue to its conclusion. This would set up Back to the Future 3, which thankfully is much less problematic in terms of how it makes changes to history, because in that film there’s only one jump backwards and one jump forwards (kind of like the first film.)
I still like this trilogy a lot, but have to admit the 2nd one is the weakest of the three. But it’s also the one with the most forward and backward time jumps going on. Perhaps it’s best to keep things simple when we make time travel stories.
And what about Jennifer? Why didn’t they keep her awake? Why didn’t they give her anything important to do? How does it make sense that leaving her on her porch in 1985A, she’ll be on her porch in 1985 at the end of the third film.
I’ll address the third criticism first. Yes, it makes very little sense that leaving her on the porch in 1985A would result in her being on the porch in 1985 at the end of part 3, no matter which theory of time travel we are using. If we use the theory I’ve been operating on, then the entire 1985 timeline would be erased, and it wouldn’t make any difference if you left her on the porch, in a ditch, or on the moon. She wouldn’t be there in 1985 at all, unless you prevented her from making the trip to 2015 in the first place. If we are going by the theory the film uses for 1985A, it only makes sense that she’s immune to changes in the timeline because she was a passenger in the time machine. Now that 1985A is being erased, she logically would be erased with it. The only way this works is that when 1985A is erased, the Marty and Doc who return from 2015 know they have to leave Jennifer on the porch because their predecessors did, but also know they need to prevent 1985A from happening even though it didn’t happen. So let’s just flip a table. It was a mistake to take Jennifer to the future if they weren’t going to do anything with her.
That’s bad writing!
Well, I won’t go so far as to say it is bad writing. You’ve got a smash hit movie and a superstar in Michael J. Fox. We also don’t have the same actor in the role. Elisabeth Shue is nothing to sneeze at, and I probably would have chosen to have her do more than go to sleep and then go to sleep some more. But would having her be more a part of the story have taken away some of the screen time from Doc and Marty? Yeah maybe. But it could have been fun to see Marty and Jennifer working together to solve Marty Jr’s problem, perhaps having a spousal argument about how to proceed even though they aren’t married yet. Maybe it would have been neat to put Jennifer in 1955 also. But for whatever reason, the writers wanted Marty and Doc alone. Part 2 is the weakest of the trilogy, and part 2 has the most Jennifer, so maybe it wasn’t the worst choice ever to take them out of it.
There have been plenty of rumors about Back to the Future 4 happening, and while we probably won’t actually be seeing this film made, EVER, I would postulate that the best way to proceed with that, given Michael J. Fox’ condition, would be to center it around Doc and Jennifer. If one could acquire the services of either Claudia Wells or Elisabeth Shue, go for it. Make up for putting Jennifer to sleep and show us how she’s gonna fix the timeline for once.