Use the F=ma

“A long time ago in a galaxy far far away” is a lot like saying “once upon a time.” It signals to us that we are heading on a journey that takes place in a different place where we will need to suspend our belief in reality and accept a world of magic, sorcery, and even the belief that George Lucas can still write a Star Wars script. Yet, how much of the impossible must we accept? Is the Force real? Did Han really shoot first? Are we actually seeing the events of a different and distant galaxy? That last one just might be the most fantastical of the bunch. What is more likely is that Star Wars takes place in a different universe, one governed by  physical laws that are completely different than our own.

There is nothing more exciting than Luke Skywalker screaming down that Death Star trench, Darth Vader hot on his heels, or Lando Calrissian spinning the Millennium Falcon through death defying maneuvers as he avoid star destroyers and TIE fighters over Endor. However, as any scientist can tell you, space battles like that are not possible, at least not in our galaxy.

The Darkside of Dogfighting
Star Wars dogfighting was based on World War II dogfighting, right down to the distinctive shape of the X-wings. The aerodynamic X-wings would work very well in an atmosphere, but would be irrelevant in space, almost impractical. Even the way the starfighters move are similar to atmospheric fighter craft. They wing over, dive, roll, and rocket around on full thrusters as if they were fighting wind or gravity. They even do a barrel roll, though that’s not what you think it is.

In truth, Newton’s First Law, an object either remains at rest or continues to move at a constant velocity, unless acted upon by an external force, would mean that an X-wing or TIE fighter would not need to keep their engines thrusting them forward the entire time. It would be a waste of fuel. Unfortunately, that also means they would be moving in only one direction. To make any turns or maneuvers they would need precision maneuvering jets all over their spacecraft, or some sort of internal gyroscopic system, and even then their turns would be lazier as their momentum kept them moving forward even as they rotated their craft along a different point.

Newton’s First Law doesn’t just apply to the spacecraft. It also applies to the pilots. Thankfully, TIE fighter pilots seem to be strapped in tight, because if they weren’t their bodies would want to keep moving in the same forward direction, even as their craft began moving in an opposite one. If not for the straps, the first time a TIE fighter made even a lazy turn the pilot would run the risk of being rammed against the bulkhead, like a brain being concussed against the inside of your skull. Canonically, X-wings have an internal atmosphere, oxygen and inertial dampeners, though to what limit that is never specified in the movies. It’s why Luke and the rest of Rogue Squadron do not have to wear respirators when they are piloting, unlike their TIE fighter counterparts, who have to wear full survival suits. Similarly, if it wasn’t for the artificial gravity inside the larger starships like star destroyers or Mon Calamari cruisers, crew and equipment would be smashing against the walls like Ewoks at a Wookiee frat part. As an example, in our current spacecraft, who for some reason have failed to master the concept of “artificial gravity,” astronauts need to be strapped in for any maneuver they make, no matter how tiny.

On the plus side, Newton’s First Law also means that a fighter craft could rotate independently of its lateral or vertical movement. So an X-wing could do a full thruster burn, then turn 90 degrees and strafe an Imperial frigate without ever losing significant forward momentum, of course it also means that they would be traveling on a predictable trajectory for Imperial gunners to target, but that is actually a whole separate problem.

In atmosphere-based dogfights, the longer you stay moving in one direction, or if you are moving in a predictable manner, the more likely it is that you will wind up full of bullet holes faster than you can say “Grandma Yoda’s Famous Applesauce.” Yet, at certain times in space combat predictability of movement would be unavoidable. Gizmodo has an incredibly interesting article on the subject where they talk more in-depth about orbits and trajectories, but sufficed to say there are only a limited number of ways a starship could enter into a solar system or make orbit around a planet, and we can predict them based upon mathematical equations.

Gravity and Hokey Religions
Star Wars even acknowledges this, as traveling through hyperspace requires an intense amount of calculation and precision or any object with a large gravitational mass, such as a planet, star, or blackhole, can forcibly pull a ship out of hyperspace or prevent them from entering. To put that another way, it ain’t like dusting crops. This means that fleets entering into star systems do so along predictable routes that can be mined, guarded, or even just observed. Even worse fleets guarding a planet or solar system will be stuck in predictable and calculable orbits.

Any battles taking place near a planet or moon-sized space station would, ironically, need to follow at least one adage of atmospheric dogfighting rules. The higher you are from the center of the gravitational mass, the more advantage you have. Fighting from a higher orbital path down to a lower orbital path would give you a significant leg-up, literally. Essentially, much like Obi-Wan, you would have the high ground, and the force of gravity to help in any attack you make against a lower orbital path, which is important.

Newton’s Second Law, the vector sum of the external forces F on an object is equal to the mass m of that object multiplied by the acceleration vector a of the object: F = ma. In other words, if you fire a proton torpedo at a Nebulon B-frigate, but it misses and continues toward the planet below, the missile’s trust plus the force of gravity acting on it, means that your small meter long projectile could impact the planet below with the force of several nuclear blasts. And we mean that literally, as proton torpedoes most likely utilize radiation.

In space, explosives are useless. Fires burn out before they even begin. Radiation is more effective as it can travel through a vacuum. Yet, the most effective weapon is actually Newton’s equation of force. If you get an object going fast enough, even if it is small, it can do an excessive amount of damage upon impact, and in the void of space where there is no air friction or terminal velocity limit (just the lightspeed limit,) a magnetized railgun fired at the right velocity could do a heck of a lot of damage against a ship’s hull. For anyone who has seen Gravity, as poor as some of its science was, they did a good job of highlighting the dangers of even small space debris moving at incredible speeds.

A More Elegant Weapon
Unfortunately, rail guns or even projectile missiles have a possible drawback in Newton’s Third Law, when one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body, or every action has an equal and opposite reaction. So when you fire a railgun, or a missile or even a laser in space, there will be an equal amount of force that presses back on your ship, changing your heading or slowing your trajectory. However, with lasers that opposite force would be significantly insignificant.

Of course, lasers have other drawbacks. Mainly, lasers are invisible, so there will be no spectacular light show, like you see in Star Wars, and no cool laser sounds, since space is a vacuum. Also, lasers only stay focused for so long. If you fire a laser at a distant target by the time it gets there your concentrated beam of death could look like nothing more than a flashlight to your intended target. That is because light spreads out over distances and even more so if it has to penetrate an atmosphere. Still for close range battles, it is a pretty good weapon, but close range in space combat is a relative term.

The Lightside of Space Warfare
Star Wars depicts battles in small areas with tightly packed swarms of ships duking it out, capital ships firing broadside turbolaser blasts into one another. It is very exciting, but the truth is that with such a tight space and no room to maneuver it is more likely that all the ships would wind up crashing into one another if they were actually that close. Real space battles will need to be fought at extreme ranges, with no visual contact whatsoever. Even worse, when you are aiming your giant cannons you would not be able to aim directly at your target. You would need to aim in front of it, using math to predict its course and trajectory, because the target you would be seeing on your screens would only be a shadow of where the ship had been previously, even if it was only light-seconds away.

For example, the light of the Sun, which is about 92,960,000 miles (149,600,000 km) away,  takes eight minutes to reach Earth. That means the sun we see in our sky everyday, is no longer where we see it. Its light is eight minutes old and the actual sun has moved eight minutes along its given path. And the distance from the sun to the Earth, one AU, is not an extreme distance in space. Even the light from Venus takes 134 seconds on average to reach Earth, and Venus is only about 162 million miles (261 million km) away. In a life and death space battle those seconds could mean the difference between a fatal blow and a near miss.

These distances would also wreak havoc with communications, even if we knew how to send them at the speed of light. Orders would have to be given in advance and then individual captains and commanders would have to be trusted to know their part in the attack plan. Admiral Piett could not call Vader in the middle of a battle to get additional instructions, even if he did not fear being choked to death for his failures.

In the end, space battles would more realistically resemble nineteenth century naval battles. You would know your enemy was coming, you would sit off from each other, each hoping to calculate the right avenue of attack. Fighter craft would less resemble mustang warplanes and probably closer resemble spheres or cubes. A starfighter would probably have jets on every side of it, so that it could turn one way or another, with the pilot rotating inside the craft. This means that the pilot could orient himself however he or she wanted independent of the ship’s exterior and fire lasers that were mounted on all sides of the spacecraft. In the end, it would probably be easier to have droids control fighter craft, instead of just riding on the top of them and screaming when they got hit by an errant laser shot.

Still, it is fun to suspend our knowledge of science and physics, much as we do when we say “once upon a time,” but maybe with Star Wars it would be more accurate to say, “a long time ago in non newtonian-universe far far away.”

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