On that day, Burtt was recording something, and crossed the room with his microphone still turned on. When he passed by a television set that was on but with its volume all the way down, the microphone let out a whine. “An unusual hum,” Burtt said. “It picked up a transmission from the television set and a signal was induced into its sound-reproducing mechanism. That was a great buzz, actually. So I took that buzz and recorded it and combined it with the projector motor sound and that 50-50 combination of those two sounds became the basic lightsaber tone.”
From there, all Burtt needed was a sense of motion, the thrumming and slashing of battle. He achieved that by taking a microphone and waving it through the air next to the speaker as the foundational lightsaber sound was playing. “What happens when you do that, by recording with a moving microphone, is you get a Doppler shift, you get a pitch shift in the sound, and therefore you can produce a very authentic facsimilie of a moving sound."
The onscreen look of the lightsaber was, of course, at least as important as the noise it made. The original lightsaber handles were made from pieces of old flashgun battery packs, from the kind of camera where you had to hold up the flash separately. In the first films, a technique called rotoscoping made the lightsabers glow; today they’re digitized.
Mesmerizing sound and a three-foot blade of colorful light make the lightsaber distinct and otherworldly; but how the weapon is wielded is what makes it classic. Epic battles are fought in the tradition of world-class swordsmen. For an object so influential in the realm of fictional technology, it is the lightsaber’s real-world elegance that makes it memorable.
Unlike a blast gun—also featured in the Star Wars universe—the lightsaber is a defensive weapon, one that’s meant to be used as a last resort. It requires skill, a sense of tradition, and that most elusive of power source: The Force. (Obviously, lightsabers aren’t exclusively used in self-defense. Villains wield them aggressively, hacking through the air with lightsabers that appear more like battle axes than artful swords in their hands.) Preparing for a lightsaber duel is like learning intricate dance steps, according to Ewan McGregor, who played a young Obi-Wan Kenobi, the Jedi master, in the more recent films. “Every stroke is choreographed,” he told the audience at a New York Times-hosted event in 2012.
Lightsabers are fantastical, but they may be technologically possible. They’re lasers, after all. (Though “lightsaber” is far more romantic a name than “lazer sword,” which Star Wars creator George Lucas used in early scripts.) Outside of the Star Wars universe, lightsabers would be powered by plasma instead of The Force.
“You would have a sword that ejects a long tube, and the tube has holes in it, which emits plasma,” the theoretical physicist Michio Kaku told the Times in 2008. “They could be heated to enormous temperatures, and in some sense, they would be able to fry any object they came close to.”