How lightsabers went from a DIY project to culturally iconic

How hot is a lightsaber? What was the original lightsaber prop made out of?
Darth Vader weilding a lightsaber
Don't mess with Darth. Disney

Summer’s right around the corner, but the heat is already on. From unrelenting sunshine to sizzling grills, feeling hot (and cooling down) are part of the daily grind now. PopSci is here to help you ease into the most scorching season with the latest science, gear, and smart DIY ideas. Welcome to Hot Month.

Who can resist a pun-based holiday? Star Wars fans have adopted May 4 (or “May the Fourth…”) as “Star Wars Day.” The idea has taken hold enough to have even branched into purist factions who honor the day as a celebration of all things Star Wars, and stricter, more orthodox sects who choose to only acknowledge the Light Side on May the Fourth and all then dedicate a day to all things Dark Side on “Revenge of the Fifth.” No matter where you fall in this theological divide, there is one thing we can all agree on: Lightsabers are cool.  

The lightsaber is simply the greatest fantasy weapon of all time. It’s iconic, it’s instantly recognizable (even by sound is recognizable), and it’s been the source of enthusiastic frustration for hardcore fans for decades. From toys that don’t quite cut it to DIY attempts at the real deal, they have been a puzzle for engineers and cosplayers alike. Let’s look at some of the fantasy and reality behind the ultimate Jedi weapon, and how close we are to wielding them in the real world.

The first lightsabers were true DIY efforts

Way back in 1977, George Lucas was a scrappy young director with billionaire ideas and a hundredair budget (this is well before Disney opened its vaults to buy the Star Wars universe), so he had to get creative. The original lightsaber hilts were cobbled together from literal spare parts, with antique cameras providing most of the raw material. Obi-Wan Kenobi’s, Darth Vader’s, and Luke’s (well, Anakin’s) sabers were all made from flash handles—Luke’s and Obi-Wan’s from an antique Graflex, and Vader’s from an MPP Microflash. Obi-Wan’s saber was a real mutt, made up not only of the Graflex camera parts, but also bits of a jet engine, a World War I rifle grenade, and a faucet knob.  

Some of that signature lightsaber glow was a practical effect

In order to give the actors something tangible to fight with and to give the special effects department something to work while adding post-production firepower, the original prop lightsabers employed an innovative technique. The hilts had small motors in them that spun long carbon fiber blades coated in a material called Scotchlite. Because Scotchlite is reflective, it bounced light while the scenes were being filmed, and that gave the FX team a point of reference when they went through and added the color. Newer entries in the franchise did away with the reflective carbon fiber blades and achieved most of the effect through CGI.  

Disney is on the cusp of releasing the most realistic lightsaber yet

Disney teased a brand new, hyper-authentic lightsaber toy back in April. How, however, the company has offered a closer look at the device, which will debut with the upcoming Star Wars: Galactic Starcruiser hotel opening in 2022. Unlike Hasbro’s Force FX lightsabers, which are essentially just light tubes that switch on and off with appropriate sound effects, the new offering will have a simple hilt—like how they look in the movies when not in use—that unfurls a glowing blade. Intrepid fans located the patent for the toy, which utilizes a flexible LED “spool,” and even a video of a magic trick that employed a similar “unfurling” technique to illustrate how it could work.  

Lightsaber blades are so hot right now

Fans, of course, remember Jedi Qui-Gon Jinn using his lightsaber to melt through enormous metal blast doors in The Phantom Menace, so it’s obvious these thing are meant to be pretty hot.  

But how hot is hard to determine, because we don’t really know what those doors are made of, or how hard it is to slice off an Aqualish’s arm. But when Force newbie Rey sliced a rock in half in The Last Jedi, it gave astrophysics and engineering enthusiast Brandon Weigel the base he needed to figure it out. Going deep into it, he arrived at a staggering figure: A lightsaber blade burns at 20,566 Kelvin, or 36,559.13 degrees Fahrenheit.

This info does make one wonder how characters manage to hold sabers without singing their eyebrows off. Some fans have speculated that sabers (or the Kyber crystals that power them) emit a kind of force field that protects the holder from bursting into flames as soon as they switch their weapon on. Sure, why not?  

Why don’t we have real lightsabers yet?

There are basically two factors that make actual, real life lightsabers impossible. One: There currently does not exist a battery small enough to fit inside a lightsaber hilt that has even close to the power needed to generate 20,566 Kelvin worth of heat. Secondly, we haven’t developed the technology to make a laser beam that stops at a certain height. Lightsaber “blades” ignite to a sword-perfect size, but the lasers we have at our disposal in the real world just keep going indefinitely (and are beams of light, so they wouldn’t really “slice” though anything. They could heat something up until it explodes, though!)  

Plasma could be the key to a real lightsaber

Plasma could be the key to making something sort of like a real lightsaber. Plasma is the superheated state of matter found in our sun and in a lightning strike. It could make for a good lightsaber blade if you could create a handle that wouldn’t melt instantly once you turned it on, and a magnetic field able to keep the plasma in a nice sword shape and length. But, once you had those, changing the color would be a snap. It all comes down to what kind of gas you add to the plasma (similar to how a neon light works)—you could add neon for a red Sith saber, krypton for a green Jedi one, and even mercury for a Mace Windu-esque purple blade. Of course, a mercury light would also give off ultraviolet rays, which would probably blind you.  

Does the color of a lightsaber indicate whether a character is “good” or “bad?”

Actually, yes. According to the expanded Star Wars universe—material beyond just the movies, like cartoons and comics and novelizations—a kyber crystal will “call” a Jedi to come claim it, and change color once it attunes with its owner. Blue is usually associated with bravery and green with harmony. Sith sabers are red because the crystals don’t call to the Dark Side types, so they have to take the crystals by force. Doing so makes the crystals “bleed” and turn red.  

Does that mean Luke Skywalker becomes more “harmonious” and “brave” once he crafts his own lightsaber?

Not exactly. Luke was supposed to have a blue lightsaber in Return of the Jedi (he’s even shown with one on the posters) but it was changed at the last minute to green. The reason was practical, not philosophical: During the outdoor desert battle that starts the movie, Lucas felt the original blade got lost against the bright blue sky.  

Lightsabers were almost called “lazerswords”

Seriously. In the first draft of Lucas’ script, they’re called “lazerswords.” It’s one of many changes that probably saved the project (Han Solo was also going to be an alien lizard).