In science fiction, more than any other genre, the role of Science is to make the impossible seem plausible. This has been the case from HG Wells through Ursula Le Guin and Cixin Liu — for all of these authors, no matter how plausible the explanations seem, science ultimately serves the story.
The internal logic and rigor of Earth’s physical universe is used as merely a scaffold for the fantasy of The Left Hand of Darkness or The Three-Body Problem, to make those plots seem feasible and immediate. The real-earth-science that is practiced in universities and labs worldwide has nothing in common with those fantasies except some buzzwords and the appearance of internal coherence.
American audiences, however, tend to get the cart before the horse, and they see the fantasy as something which should have not only the same degree of internal coherence as Earth’s physics, but also the exact same coherence! In other words, it’s not enough for Harry Potter’s spellcasting to seem logical and plausible, it must also be logical under the self-same rules that real-world physics impose!
This uniquely modern audience assumption is both hopelessly naive and demonstrably false. To prove this, I’ll examine the physics of everyone’s favorite galaxy far, far away: Star Wars.
1. Sound in Space
Ben Burtt is the legendary sound designer of the Star Wars saga, and is a huge reason that the films were as successful as they were. No matter how much you like or dislike the series, you know what a Wookiee sounds like, and you may even be able to imitate the sound of an X-Wing’s lasers firing on the Death Star.
Here’s the problem: under Earth-physics, there is no sound in space at all. See, sound takes the form of a wave — as I type these words, my tapping keyboard is displacing air molecules, which ricochet off one another until they reach my ears, vibrating my ear drum, which my brain parses into sounds. Space, by contrast, is definitionally a vacuum, and therefore sound waves have no medium through which to propagate. So, under Earth-physics, the audience should not be able to hear any sound of space combat, unless the camera places us in a ship at the same time that ship is struck by a laser or asteroid (in which case the sound would propagate through the ship’s pressurized cabin).
The audience, upon recognizing this dissonance, is therefore left with three options, which I’ll return to again and again:
- There is some information the audience is not privy to that rectifies the inconsistency of sound in space according to Earth-physics. Maybe Star Wars is really a documentary in the Star Wars universe, and the in-universe editors are adding sounds in post-production. Maybe Star Wars cockpits have surround sound that makes laser noises as a way of warning the pilots. Etc. These are attempts to change the story, keeping Earth-physics constant.
- The Star Wars universe is operating in accordance with its laws of physics, but those physics look nothing like ours. Maybe Star Wars’ space is not pure vacuum, and there is a graviton-like substance that transmits sound without interacting with any other particles. In other words, this approach keeps the movie the same at the price of our Earth-physics assumptions.
- The meta-literary option is that Star Wars is a fictional space opera, and therefore the authors were more concerned about telling a good story than they were about the rigors of physics. On one hand…this is objectively, irrefutably true. (Sorry, but George Lucas doesn’t give a Hutt’s booger about academically rigorous physics.) On the other, I see a lot of people worked up over the plausibility of Star Wars, which isn’t really addressed by this option, so I’ll leave it aside for the remainder of the essay.
2. Gravity in Space
In The Last Jedi‘s opening scene, a group of heroic Resistance pilots drop bombs onto a Dreadnaught to destroy it in the skies above D’Qar. It looks great, except… according to Earth-physics, there should be very little gravity in space.
Earth-physics knowledge: Gravity is an inverse-square law, meaning that the gravitational pull of an object is inversely proportional to the square of the distance between those objects. If Item A is three times as far away from the sun as Object B, it will feel 1/9th the gravity. Recent discoveries have picked up “gravity waves” on massive antennae, leading to the theory that gravity is propagated through space by the as-yet-undiscovered “graviton” (a particle that is to gravity as photons are to light, or as electrons are to electricity).
The fact remains, though, that the bombs in The Last Jedi fall quickly and evenly toward their target — there’s no acceleration to imply they are feeling an increasingly-stronger gravitational force. Under Earth-physics, the bombs should either fall towards the more massive D’Qar or not fall at all (the same logic also applies to the arcing lasers fired by Snoke’s Supremacy later in the film).
Again, we are left with 3 options (which I’ve narrowed to 2, excluding the option that is meta-literary):
- We’re missing plot information — the bombs are specially magnetic, for example (which is actually revealed in the film’s novelization). However, I don’t find this answer compelling — why isn’t the bomber itself ferromagnetic as well? Why were the bombs not attracted to the other nearby Star Destroyers as they fell, which would evidence itself as curvilinear fall paths?
- The physics of the Star Wars universe are fundamentally different than our own. Perhaps the Star Wars “graviton” equivalent (which also transmits sound) affects different materials unequally, or perhaps it’s merely that Star Wars gravity doesn’t behave according to an inverse-square law!
3. Asteroid Fields
One of the most thrilling scenes in Empire Strikes Back is the chase through the asteroid belt, Falcon vs. TIE bombers, with asteroids flying left and right. A similar scene is present in Attack of the Clones, as the Fetts chase Obi-Wan above Geonosis and release sweet-sounding bombs in the dense thicket of rocks. Under Earth-physics, neither scene could have happened.
Earth-physics knowledge: Since there’s very little matter in “empty space”, an object’s velocity is largely determined by the conservation of momentum. An object’s momentum depends on its mass and the strength of any impacts upon it (think billiard balls). Therefore, our own real-world asteroid belt is like watching a time-lapse of billiard balls — if two asteroids ever collide, they bounce off one another, and the object with a greater momentum transfers its momentum to the other. This means that the two asteroids tend to travel away from each other, instead of cohering as a dense field of hurtling obstacles. Due to the law of momentum, our galaxy’s asteroid belt is necessarily as sparse as oases in the Sahara, and the asteroids that do exist are often pebble-sized, having long-since been annihilated by repeated impacts.
In other words, if the famous chase scenes had taken place in our galaxy’s asteroid belt, it would have looked like… a normal chase, no asteroids in sight.
Our options:
- We’re missing plot information — perhaps no one told us that this asteroid belt was recently formed! Maybe it’s Alderaan (too soon?). It will disintegrate like Earth-physics asteroids given a few million years.
- The physics of Star Wars are fundamentally different from our own. These asteroids are highly self-attractive, with the force of attraction greater than the impulse of momentum, so these asteroids tend to cohere into ever-bigger masses rather than fly apart.
4. Time is Broken
Have you ever noticed that, in Empire, Luke trains for what seems like months with Master Yoda, and meanwhile Han and Leia take a straightforward A-to-B path to Bespin? Similarly, in The Last Jedi, Rey trains for days with Luke, while the Resistance flees the First Order for just a few hours. Even in Attack of the Clones, Anakin and Padme have a nice multi-planet vacation while Obi-Wan does a couple days’ sleuthing. The times don’t add up, at all! And yet, in each case, the characters rendezvous after their adventures as if there were no disjunction. Why this difference in the subjective time spent by our interplanetary protagonists?
Earth-physics background: The theory of relativity was proposed by Einstein in the early 1900s, and physics has never been the same. The idea is that, if objects are traveling near the speed of light, they will experience time more slowly than a stationary referent. A (fairly accurate) example of this is Interstellar, where the spacefaring father ages only a few years while his young Earth-bound daughter grows fully into old age. The results of relativity are completely negligible unless one travels at ~90% the speed of light, a speed many physicists believe is impossible to reach for Earthlings.
At first, this might not seem like a contradiction — after all, Han and Leia were traveling, and Luke was staying still on Dagobah, so wouldn’t that agree with earth-relativity? Well…no. Careful observers will note that Han and Leia never jumped to lightspeed! Luke was the only one who jumped, and Luke was the one who experienced a longer time, which is backwards of what earth-relativity leads us to expect!
(Not to mention, it might be earth-physically impossible to even reach lightspeed for objects more massive than photons, so there’s that. Han’s brag of reaching “0.5 past lightspeed” should be impossible in Star Wars.)
Again, our two options:
- We’re missing plot information. Maybe Han and Leia went to a romantic hotel after Hoth but before Bespin. Maybe the in-universe documentary crew cut the order of events poorly. Maybe Han is just a compulsive liar about making 0.5 past lightspeed.
- Star Wars physics is utterly unlike Earth-physics, where lightspeed is possible and relativity runs backwards.
Conclusion
Star Wars, as we have received it, is simply incompatible with cutting-edge Earth physics. From a literary perspective, these “plot holes” taken together mean that either Star Wars is a flawed and incomplete narrative, or its physics are fundamentally, irreducibly different than those we are used to on Earth. (And that’s before getting into the physical ramifications of the Force!)
Perhaps unsurprisingly, I prefer the view that our physical assumptions are at fault, rather than the internal logic of Star Wars. I’d rather re-calibrate my expectations than develop nine movies’ worth of psuedo-scientific headcanon.
The same goes for any other fantasy, whether it’s Harry Potter or Lord of the Rings — by liberating myself from the expectation of a 1:1 match for Earth-physical accuracy, I’m able to fully immerse myself in the internal logic of the story, a story which takes the science for granted in service of compelling character and plot.
However, it’s worth noting that my nerdy inner scientist still has one last real piece of science to chew on:
Earth-physical cliffhanger: The famous Big Bang theory holds that the universe is exponentially expanding (experimentally, this is due to the wavelengths of cosmic radiation; theoretically, it’s due to this sweet nearly-omnipotent number called “The Cosmological Constant”). Under this theory, our universe is like an inflating balloon — but some physicists believe it’s possible for little baby balloons to initiate off the first one! These “pocket universes” may have unique physical properties (for example, one where Star Wars’ physics are normal, one where Harry is indeed a wizard, and one full of thrones and incest). The physicists who adhere to it also use this theory to explain why Earth’s universe has the precise conditions that lead to life — they posit an infinite number of pocket universes exist, such that it’s inevitable that we’d exist in one with life-supporting rules. But, much like explaining sound in Star Wars, that may be reading too much into the text!
Until next time!