The use of a lightsaber in battle would require skill, superhuman speed, and the ability to react quickly. But this is assuming the weapon would actually be useful against modern weaponry. Despite producing varying levels of kinetic energy, no human could move fast enough to block 30 shots from a machine gun or pulse rifle, with or without a lightsaber.
So just how useful would a lightsaber really be in battle? Well, there are internet memes aplenty that give an indication of the faith people have in lightsabers. But is this “civilized” weapon science fiction or science fantasy? We dive in.
Lightsabers in the wrong hands
Practical use of a lightsaber would require the skill-set as proposed in the movie, such as the ability to predict the future on an instant and microsecond basis, and then the superhuman ability to physically move in reaction to those foreseen events.
Here’s a reconstruction of what you might find…
The brown portion is probably not too far away from the truth unless you also stipulate the existence of The Force, and the owner being proficient in its use.
Science fantasy
It’s lucky then that Star Wars never aspired to be science fiction, and decided on science fantasy instead. This freed it from normal physics and consequential events that require an intricate explanation and set Lucas’ imagination free to explore. As a result, he told a great story reminiscent of the movie serials of his youth where heroes rescued princesses.
Ask yourself, however; could you dodge, deflect, or even return an incoming pulsed energy charge? In reality, would a lightsaber blade act as a mirror for a laser beam or would a bolt simply pass through the light beam?
Those blasters weren’t merely light, either; they contained particles that gave a kick (cf. Tibanna Gas, which imbued it not only with various colors, but corresponding levels of power).
Red was the weakest form of gas charging for blasters (and cheapest, thereby being what the Imperial Army chose). Green and blue were incrementally more powerful, with yellow and purple being “exotics” of indeterminate value in the Star Wars canon. Color aside, they provided kinetic energy.
Physics
That means there was a kinetic effect from blaster bolts as demonstrated by them physically knocking people back and down. Consider holding an aluminum baseball bat tightly and someone shoots the far end with a bullet while it is in your hands. Even presuming it didn’t disintegrate, the wave of kinetic energy would travel its length and into your hands, probably injuring them, and then cause you to drop the bat.
With conventional, real-world physics, if a lightsaber met a blaster bolt, at the very least the blade should be deflected away. It shouldn’t behave like a mirror and a five-milliwatt cat-toy laser beam. Luckily, it was Science Fantasy, so it could work any way that good old George wished, without explanation.
In the real world, however…
This is not a weapon you would like to equip your army with, even with the best training. Two people in close proximity would inevitably injure each other, let alone the damage a lightsaber-equipped platoon could do to each other.
Such an outfit would do the enemy’s work for them, accidentally slicing and dicing themselves almost as soon as deployed. A smaller version might be used as a bayonet, and be less dangerous to fellow soldiers, but it is extra technology that could fail, so why not use a real bayonet? The function would be exactly the same except it might make it easier to quietly open a locked door during Dark Ops.
Indeed, deploying a lightsaber in the field would cause every enemy to target you instantly as you brandished your “I’M OVER HERE” attention-getting light-stick; a glowing sword is not a discrete weapon.
How could it be used?
Kept secured and off, one could employ it for quiet entry as mentioned, slicing through any lock, safe, container, or door in just moments. It could lop off the head of an individual walking by, from a discreet alcove in a sewer or castle. It could make a good stealthy assassination weapon if it was considerably shorter and more compact.
Except for the first use in the Mos Eisley Cantina, the weapon was known for cauterizing the wounds it made and preventing blood loss. Killing someone in a crowd would be clean, fast, and allow a complete escape before anyone noticed something was amiss.
The problem is that all of these things can currently be accomplished by existing means. We don’t require evolving a new technology to contain a light/photonic/plasma type beam into a portable format, designed to behave like an antedated or outmoded sword. As soon as guns were invented, swords became largely irrelevant for armies.
Bullets
One type of story-telling is not intrinsically better than another. Science Fantasy and Science Fiction can live in peace, and the short form SF was specifically created to be inclusive, not just of those two aspects, but Speculative Fiction as well. It certainly simplified the lives of librarians and booksellers to be able to group all those books together.
In another franchise, albeit different because it is based more on the science fiction concept where there are rules and internal self-consistency, Jean Luc Picard made a kinetic discovery on the Enterprise’s holodeck during a Borg invasion. Borg personal shields could not adapt to kinetic lead bullets from a machine gun. Did this cause the Federation to switch to kinetic weapons to fight the Borg?
Nope…that would have made it too easy to fight them and wrecked the storytelling.
Similarly, however, lead pellets spewed at a lightsaber user at 600 rounds per minute would certainly overwhelm them. Consider how a lightsaber was essentially useless against Darth Vader tossing large sections of industrial conduit at Luke during their first duel.
As a romantic tool/weapon, it made the story friendlier, suggesting that you might be able to participate to save princesses, and stop an evil empire. But it also made it less than easy so you could worry about the outcome.
Or, as Obi-Wan Kenobi pointed out:
“This is the weapon of a Jedi Knight. Not as clumsy or random as a blaster; an elegant weapon, for a more civilized age”.
But a lightsaber most certainly did not belong in the hands of someone without “Force” skills and training. To a person on the street, it would have been worse than useless—it would have been personally dangerous.
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