Time, The Fourth Dimension, Visually Explained
How Star Wars: The Last Jedi was able to show what so far no physics lab could
It’s late December. A new tune has snuck into the holy annals of December classics alongside “Jingle Bells”, and “White Christmas”, and it’s John Williams’ “The Force Theme”. Watching the latest entry into the Star Wars universe come year’s end has become both one of the most inspiring and also one of the most profitable holiday traditions in recent memory. Though the latest addition to the Star Wars canon, The Last Jedi, only received a modest welcome from the general audience, I loved the film.
In particular, one scene stood out for me. The montage where Rey fights against the allure of the Dark Side and searches for her lineage was not just a feat in imagination, but in engineering and cinematography as well. It truly plumbed the perverse imaginations of all filmmakers involved. From my academic perspective, watching Rey snap her fingers backwards and forwards through time was a perfect visual example of what physics professors have been trying to teach for years. Most people know or have heard that time is the fourth dimension, but honestly, it is quite an abstract concept. But it was finally a Star Wars movie of all places that demonstrated the concept clear as day.
So in grade school perhaps you were introduced to the number line. Maybe it was even pinned along the top of your classroom door. As you leveled up, in middle school you were introduced to the Cartesian plane, the world of two dimensions, where something called a slope exists, and lines can now extend in all directions. And then conceivably in high school you learned about three dimensional planes, which describe the outside world you can see and interact with everyday. If you did enough drugs or were nerdy enough, you may have then heard or read about Einstein and the work he did related to time, and how time can be intuited as the fourth dimension.
Unfortunately, time as a dimension is not something that can be as easily demonstrated on a number line or plane like the other dimensions previously mentioned. Cue Star Wars: The Last Jedi. If you’re like me, unless you see something with your own two eyes, it might as well just be cotton candy. And though scientists have been able to rigorously prove the existence of time being the fourth dimension for a while, (and in fact using it as a foundation for many modern physics concepts) the only people who can understand it are the people who have the superpower of staying awake during physics lectures. But I promise the juice is worth the squeeze. Here’s the scene again to refresh your memory.
Imagine the plot below.
The red line represents the line y=1. In a two dimensional space, this line represents all the values of X where Y is 1, from (0,1), (1,1), (2,1), to (100, 1), (101, 1), etc. Can you see how Rey’s mirror scene in TLJ represents what a line in the time plane might look like? The subject, that’s Rey, or what exists in three dimensions (x, y, z) is being held constant just like our y-value in our example above, and what is being plotted in the scene is t, time. Each frame of Rey in that scene represents (1s, Rey), (2s, Rey,), (3s, Rey), (-1s, Rey), (-2s, Rey), etc.
The hard part about visually explaining time is that a person can only experience one instance of time, t, at a time, but with the power of a camera and the science of video editing, it is now possible to see the same “frame” backwards and forwards through time. There’s sadly almost no magic or mystery to it. The future is no longer hidden, and the past no longer forgotten; it is simply one point after another point. From this perspective, it’s easy to see why, collectively, almost all religions have a notion of an afterlife, and origin stories. Both religion and science alike are human attempts to explain what we cannot understand. Time is not an abstract concept, in fact, it is simply a dimension and therefore can be explained with a line.
Which means there’s likely one last question you’re probably already thinking of: is our life deterministic? Has our “time-line” already been carved in stone from the moment we were born, without any chance for us to alter it? The bad news answer is sadly, yes. Our time-line is immutable and as rigorous as the line graphed above. However, the good news answer is that we must remember that there must be higher dimensions beyond time. In fact, there are likely infinitely higher dimensions. Of which the next dimension up must be conceptually parallel universes.
Imagine the line y=1 again from above. If we just think about it in two dimensions, then yes, there is simply one line. But if we go up to three dimensions, y=1 is no longer a line, but a plane. And therefore there are now infinite lines where y=1. And likewise for time. Essentially, from the moment we are born, yes, the line of time you are set in is constant. And if you move up and down that line, you will see the same events over and over. However if you move into the orthogonal fifth dimension, what you should see is an infinite number of parallel universes stemming from every discrete point on that once lonely line. So yes, in this timeline you are sitting here reading this article on a computer, or maybe on a phone somewhere, and after finishing reading you will get a coffee. But there are literally infinite things you could do after reading this article. Why get that coffee? Perhaps the braver you will respond to that text from your crush, or the more tired you will go straight to bed. It’s not all just possible, in fact it has already happened. Every one of those infinity possible events resides in one those infinitely parallel universes. So until the next Star Wars movie comes along and shows us which particular time-line we are all on, the past will continue to be the past and the future will forever be mystery.
