Updated: Oct 30
Whether you are a science fiction fan or not, it’s safe to say that you’re familiar with the idea of time travel. Familiar is a tricky term though. Nearly every major sci-fi franchise (and even some rom-coms) has touched on the phenomenon, so you would think that fans would know what to expect with each new time travel movie. The fact of the matter is however, that with each iteration of time travel usage in pop-culture, comes a different method of explaining the ins and outs of its complexity. Some of these uses are super creative and explained incredibly well. But time is volatile and un-relentlessly convoluted. Basically, as Tony Stark put it in Avengers: Endgame, “You mess with time, it tends to mess back”; meaning that no matter which way you stack it, there’s no perfect way to explain time travel. That being said, let’s explore some of the most popular movies and TV shows to adventure through the fourth dimension, and their pros and cons.
Back to the Future: Conventional Singular
In 1985, director Robert Zemeckis and writer Bob Gale introduced us to the first of three time travel adventures with the iconic duo Marty McFly (Michael J. Fox) and Doc Brown (Christopher Lloyd). While time travel was no new concept at the time, it’s fair to say that Back to the Future’s massive appeal popularized and cemented the conventional status quo for understanding time travel. Not to speak on behalf of everybody, but the majority of people who grew up having watched Doc and Marty change the past and future normally default to the rules used in Back to the Future to rationalize or compare new uses of time travel. So it’s only fitting that we discuss this famous trilogy first.
Let’s focus on the first (and arguably the best) movie of this trilogy. Although the mainstream conception of time travel is often traced back to Back to the Future, it simplified aspects of time in a roundabout way. Specifically, the film modifies how the Butterfly Effect theory is perceived. This is a fairly well known concept of chaos theory that suggests the tiniest change in time and space could have vast repercussions on future events. Whereas in Back to the Future, future events are only changed by past events that have a direct causal link. For example, in the first film Marty accidentally interferes with his parents being born. He then seeks out a younger (but equally as grey) Doc Brown to get his parents back together. However, in the process of doing so, he also teaches his dad to stand up for himself and grab the bull by the horns. Normally, such drastic changes would lead to a future that is WILDLY different when considering the Butterfly Effect. For all we know, Marty could have endangered his existence even further than he did originally. Instead, Marty’s life remains largely the same by the end of the film: he still grew up to want to be a rockstar, still lives in the same house, is still dating Jennifer, and still became best friends with Doc Brown. All that has changed is the nature of his parents’ relationship and his father’s success, which shows that the Butterfly Effect doesn’t completely hold water in this instance.
The second thing to note about Back to Future’s use of time travel is that everything takes place on a singular timeline. No branched timelines. No alternate realities. Allow me to explain. When Doc and Marty change things in the past, they can tell immediately if their efforts have succeeded by looking at things such as pictures and newspapers from the future. If the picture/headline transforms then they know the future has been altered. In many other uses of time travel, this would not be possible, because changes in the past would consequently create a different future where those objects did not come to exist.
This leads us to believe that Back to the Future also does not use the “Grandfather Paradox”: Travel back in time to kill your grandfather, and then you are never born, hence you are unable to kill your grandfather. In Marty’s case, if he travels back in time and changes the way his parents fall in love, this would change the way he was raised, thus changing the way he grew up, thus he wouldn’t have travelled back in time. That being said, everything takes place on one timeline because when Marty returns to the future at the end of the first film, he is still able to watch the version of himself from the beginning of the movie travel back to the past. Scenes like these, where Marty needed to hide from his second self or Doc came face to face with his younger self became some of the most enjoyable parts of the trilogy.
Now it should be noted that although the first Back to the Future introduced mainstream time travel in this peculiar new way, it really sticks to its guns the entire time. It’s consistent, emotional, and well written which is a rare find. So what are the unbiased pros and cons of this iconic time travel adventure?
Mainstream enough for the majority to grasp onto quickly (especially in a comedic sci-fi setting akin to Back to the Future)
Reduces the confusion and contradictions of convoluted paradoxes and branched realities
Higher emotional stakes, due to focusing on the attachment to a single timeline being restored
Able to use visual aids such as newspapers and pictures to confirm the change of the singular timeline
Ability to have multiple versions of the same character on screen allows for suspenseful and creative plot sequences
Theoretically incorrect for the following reasons (making it easy to invalidate certain plot points):
Doesn’t fully acknowledge the results of the ‘Butterfly Effect’
Doesn’t fully acknowledge the Grandfather Paradox
Doesn’t recognize branched timelines
Using a singular timeline requires careful choice of language to avoid contradictions
As the story becomes more complex (especially in sequels), it can become restricting
Harry Potter/Game of Thrones: Linear
Fast forward a few decades into the fantasy worlds of Harry Potter and Game of Thrones and we find a new time travel ideology known as “linear” time travel. This type of time travel is quite unique compared to the others in this article; and considering the amount of complexity surrounding the topic, it’s relatively easy to grasp. If you are unfamiliar, it is essentially very similar to a self fulfilling prophecy. In the simplest of terms, linear time travel means that anything that happens on a timeline was always meant to happen. If you travel back in time, you may think you are changing the past but you are only fulfilling what was always going to happen anyway. Let’s revisit how it was used in The Prisoner of Azkaban.
At the top of the third act of the film, Harry and Hermione wish to save Buckbeack the Hippogriff from execution and rescue Harry’s godfather Sirius Black from his sentence to the Dementor’s kiss. By using a magic device called the time turner, they travel a few hours into the past to follow their other selves to influence the future in a different way. What they soon realize is that previous events (a vase breaking, a wolf howling, and an apparition of someone identical to Harry’s deceased father) were in fact just their other selves trying to change the past. In the end, they realize that originally it only appeared as if Buckbeak and Sirius were doomed. This illusioned state of failure motivated them to change things when in actuality, by travelling back in time they were only fulfilling what had already happened.
Years later Game of Thrones put their own spin on linear time travel that served as one of the most emotional moments of possibly the entire series. Fans of the critically acclaimed show are certainly all familiar with the infamous Episode 5 of Season 6 called “The Door”. It’s hard to forget how the stinger episode ending explained the origins of gentle giant Hodor’s strange speech impediment all while showing us his heartbreaking yet noble death. For those of you who have not watched the show, Hodor served as the lovable muscle for a paralyzed Bran Stark as he searched for answers regarding his powers as the all knowing Three Eyed Raven. He often brought a smile to viewers' faces with his innocent behavior and limited vocabulary of only being able to say his own name. Bran’s powers were previously ill defined as he could seemingly induce his mind into visions of any point in history, as well as possess people for short periods of time. However, in this episode he combines these two powers much to his own regret. While Bran’s mind is caught in a vision of the past when Hodor was a child, Bran’s body is in danger of the enemy’s army. By using his warging (possession) powers on young Hodor he is able to control present Hodor making him carry them to safety. While it was previously very vague regarding the extent to which Bran could/could not affect previous events in his visions, young Hodor suffers a seizure and hears the cries of Meera Reed telling him to “HOLD THE DOOR” to prevent the army of the dead from breaking through to Bran’s body. Young Hodor writhes on the floor repeating these echoed words until they are mangled into his new iconic yet horribly tragic speech impediment “Hodor”. Thus, Bran stands mortified at the sight of the dark potential his powers have with linear time travel.
Despite being relatively easy to understand on the surface level, the main thing that makes all linear time travel so confusing is the existence of a base timeline paradox. Regardless if certain events were always destined to happen, there must be a base timeline in which those events did not happen. Thus causing the characters to want to travel back in time and ultimately fulfill the inevitable. Take for instance the previous Harry Potter example. Although we find clues that Harry and Hermione were influencing events the entire time, they themselves don’t realize this until they actually travel back in time. How could Hermione have broken the vase and distracted the werewolf if they had not yet travelled back in time? This is likely causing your mind to spin in every which direction trying to figure out how the linear loop was started. This is sadly a very unfortunate flaw in what is otherwise a great method of time travel.
Good balance of complexity and easiness to grasp conceptually without too much thought on the viewers end
Very entertaining to watch as the self-fulfillment unfolds
Well suited for the use of big reveals, plot twists, and “A-HA” moments
Hard to use as the basis for an entire movie since nothing can truly be changed
The stakes normally aren’t as high unless you introduce it in a roundabout way (Game of Thrones)
Becomes confusing when you consider the base timeline paradox
Groundhog Day/Happy Death Day/Palm Springs: Time Loop
Do I even have to explain this one? Nearly any movie fan has seen movies with a time loop element before, whether it be Groundhog Day, Happy Death Day, Source Code, Doctor Strange etc. to the point where they’ve practically become their own entire genre of films. The core concept stays the same amongst most/all of them: a main character is stuck in a repeating period of time seemingly forever until they learn a lesson or go through some drastic life change. What differs the most among these movies is the reasoning how characters enter and exit the loop. This can often vary or not be explained at all (I’m looking at you Happy Death Day), however, some films take a really creative approach with it. Most recently and most notably the Hulu original Palm Springs sees the main characters proactively study quantum physics to figure out a way out. All in all, although it’s not a traditional form of time travel compared to the other examples in this article, time loops certainly deserve to be discussed.
Most simple method to construct on screen
No confusing reality paradoxes
Versatility lends itself great to many themes: comedy, sci-fi, action, drama
Harder to be creative and differentiate from other films in the genre
Easy to be lazy when explaining the mechanics of the loop
Avengers Endgame/Click: MacGuffin
What the hell is a MacGuffin?... is what 90% of you are probably asking yourselves right now. In layman's terms, a MacGuffin is an object in a movie/film that serves entirely as a trigger for the plot. In Lord of the Rings the macguffin would be the ring, in Indiana Jones it would be the ark of the covenant or the holy grail, in The Cat in the Hat it would be the giant red box where Thing 1 and Thing 2 come from etc etc you get the gist. To make a long story short, some films use the abilities or properties of a MacGuffin to explain how the rules of time travel work. Two great examples of this are the beautiful ending to the Infinity Saga that is Avengers Endgame and the surprisingly heartbreaking tear-fest that is Adam Sandler’s Click.
Let’s start with Avengers Endgame. In this case the Macguffin is, of course, the Infinity Stones. When a group of Avengers travel back in time to the events of the first Avengers film, Bruce Banner attempts to take the time stone from the Ancient One to which she responds:
"I'm sorry, I can't help you, Bruce. If I give up the Time Stone to help your reality, I'm dooming my own…The Infinity Stones create what you experience as the flow of time. Remove one stone and that flow splits”
So in the example of the Marvel Cinematic Universe, removing an infinity stone (MacGuffin) from the period of time it belongs, results in creating alternate realities. Normally, a parallel timeline wouldn’t be a huge deal. However, in this case a branched timeline cannot exist without all 6 six Infinity Stones otherwise it will end up corrupted. While this can seem confusing, it’s important to remember that every MacGuffin is different.
In 2006 Adam Sandler gave us the answer to a question that everybody has at some point in their life: What would it be like if I had a TV remote that controlled my life? The reality: Not as fun as it seems. In the case of Click, time travel or rather time manipulation is explained through the MacGuffin of the universal remote. Functioning exactly like a television remote, Sandler’s character Michael Newman can pause, rewind, fast forward etc. throughout his entire life. While he cannot change the past, he can inadvertently change future events by fast forwarding. By choosing to fast forward, his body remains in a monotonous autopilot state during the time he skipped over. Consequently he is unable to fix what he skipped over, causing his life to go down the deepest of depressing gutters. It also, makes no mention of parallel/alternate timelines or paradoxes. To make a long story short, it’ll make you cry. Regardless, it may not be the best film out there but it is a perfect example of a good use of a time travel MacGuffin.
Gives the writer/director lots of freedom and creativity because mechanics largely depend on the MacGuffin itself
Allows for the ability to instate or ignore any rules of time travel according to how the MacGuffin operates
Creates many opportunities to build tension and suspense considering the plot rests on the fate of a certain object
Depending on the MacGuffin it’s easy to write the story into plot holes or tight corners
Requires a lot of explaining to not come off confusing
Avengers Endgame: Theoretically Correct
I know I know, I already talked about Endgame already. Yes it’s true that it’s an incredible masterpiece that I would make any excuse to talk about more. But… it also explains time travel in two different ways so it needs to be addressed.
Although the infinity stones hold together the flow of time as the Ancient One explains it, the timeline of Avengers Endgame still functions on other ordinary rules. Near the beginning of the film, The Hulk is quick to make jokes about popular time travel movies after Rhodey suggests going back in time to kill baby Thanos so that he will never grow up to cause destruction. To this Hulk replies:
“Think about it, if you travel to the past, that past becomes your future, and your former present becomes the past, which can’t now be changed by your former future.”
To which Ant-Man replies:
“So Back to the Future is just a bunch of bullshit???”
It’s easy to see how this can come off as confusing, but the main thing to note in this explanation is that changing the past does not change the future. By acknowledging theories like the Grandfather Paradox and The Butterfly Effect, Avengers Endgame basically states that changing the past merely spawns alternate timelines where the future will play out differently. However, the timeline that the Avengers are from will remain the same. For example, when the evil version of Loki escapes with the Tesseract during the second act of the film, such a big change in the timeline activates the Butterfly Effect/Grandfather Paradox creating a new timeline. The Avengers main timeline remains unchanged in the future, but now there exists a branched timeline where Loki escaped and may have never redeemed/sacrificed himself. So technically, Back to the Future isn’t quote unquote “correct” but one thing’s for sure, it is much more consistent than Endgame. Things were pretty smooth throughout the film until they decided to throw a wrench in the mix with the old man Captain America scene at the end. This brings us back to the point of this article: no explanation of time travel is perfect.
Theoretically correct for fully acknowledging Butterfly Effect, Grandfather Paradox, and branched timelines
Forces you into more creative solutions since the past cannot be changed to affect the original timeline
Opens the door to a myriad of opportunities with alternate events and alternate characters
Overall more confusing to the mainstream than other methods/ideologies
Can become very chaotic if too many parallel timelines come into play
Hard to keep track of exactly how many alternate timelines were created
Consistency becomes much more difficult with various timelines and alternate characters (especially if you want to include twists and surprises)
About Time/Deadpool 2: Redo Button
This final time travel ideology doesn’t show up often and only differs slightly from the previous methods we’ve analyzed. As we’ve seen previously in films like Back to the Future or Avengers Endgame, travelling back and forth through time leaves open the possibility of running into another version of yourself. Whether that be younger you or older you, it’s something that is widely accepted to be a part of time travel film. The “Redo Button” method as I have arbitrarily named it, ignores this phenomenon.
In Deadpool 2, Deadpool sacrifices himself by deactivating his healing powers and diving in front of a bullet for young mutant Russell. Instead of using the last of his fuel to travel back to the future where he belongs, Cable decides to travel right before the battle in order to place a skeeball token in Deadpool’s pocket to save him. By travelling to the past Cable does not run into his younger self. Instead he relives that period of time as if it never happened before (with no mention of branched timelines or paradoxes). The other X-Men movies such as Days of Future Past also use a version of this form of time travel, albeit with a different way of sending your body back in time. Overall, pretty simple if you ask me.
Similarly in the romantic comedy About Time, Tim learns from his father that the men in his family have the ability to travel through time. He can close his eyes and return to any period in time that he’s already experienced. The difference here from other films is that there is not a second version of himself in the past. You can almost think of it as him hitting a redo button. This again doesn’t create any branched timelines or paradoxes. All it does is picks him up and drops him into a moment of his choosing. Although it may seem like the stakes are low for this form of time travel, this film constantly brings Tim face to face with the emotional burden of his power. He has the power to essentially change the past to make anyone happy. However, he can’t please everyone. Thus, he is forced to choose the right way to use his powers which sometimes causes him to erase periods of time that brought him or others happiness.
Provides less obstacles when trying to use time travel to advance the plot quickly
Can be used to strike emotional beats really well by erasing periods of time
Easy for the stakes to be perceived as low
Can be seen as a cheap gag if implemented lazily
Not too much versatility in its uses
As we’ve seen in all of these examples, time travel is just as confusing and conflicting as it is interesting and enjoyable. It’s tough to say if we’ll ever be able to explain the phenomenon in a way that makes complete sense to be honest; but some would argue that’s part of the fun. It’s likely that we’ll see time travel movies and television shows continue on for the rest of time; and with each one we are sure to experience a uniquely enjoyable spin on the fourth dimension and the mysteries that come along with it.
Written by Jake Zall
Edited by Nick Mandala