Engineers Made A 'Lightsaber' That Retracts And Can Slice Through Steel

Updated September 8, 2021

Science fiction has a solid history of coming up with ideas for ways to make lives easier and better that have since been brought to life by inventors and engineers.

It wasn't all that long ago that video calls were thoroughly in the realm of science fiction, for example; now, FaceTime and Zoom are a way of life. Tablet computers were featured in 2001: A Space Odyssey and Star Trek: The Next Generation long before Apple iPads became common.

But communication devices and computers are a far cry from some of the more fantastical ideas science fiction has put forth. For example, the lightsabers in Star Wars. Those laser swords are undeniably cool, but they're also terribly unrealistic.

But then, that's what's been said about so many things until someone went and actually built it.

Building a real lightsaber that can do all the things a movie lightsaber can do ought to be impossible.

Lasers that extend and retract and stop mid-air, have enough mass to clash against other laser swords, and can slice through just about anything — all while powered by a tiny crystal in the handle — just don't fit into physics.

But mere physical impossibilities aren't going to stop some dedicated engineers from trying.

Enter Hacksmith Industries, a group of engineers and makers who have made a name for themselves by re-creating lots of movie magic in real life and putting their builds on YouTube.

They were determined to create a working lightsaber and they've tried a few approaches in the past, including a super-heated titanium rod that could indeed slice through lots of things and people could fight with them, but other than that, didn't really check a lot of lightsaber boxes.

And so they set out on something of a do-over, with some new ideas for how to make something more like the movie lightsaber.

What they came up with still doesn't technically meet the definition — as they fessed up, it's more of what the Star Wars lore would call a "protosaber" because it needs an outside power source rather than one of those fancy little crystals to make it work.

But boy, does it ever work.

The key to this build is laminar flow.

It's the same phenomenon that makes a stream of water look solid. In this case however, it's a stream of liquid propane gas — the same stuff that powers barbecues — for which Hacksmith team adapted a special nozzle used in glass blowing.

The result is a stream of gas that's super-heated to about 4,000 degrees F (about 2,200 C) and looks very much like a lightsaber.

To give it even more Star Wars authenticity, they came up with a way to make their lightsaber change colors.

Introducing different chemicals to the gas flow changes the hue of the "blade," much like adding chemicals to a campfire.

In this case, boric acid gives it a Yoda-appropriate green, while calcium chloride changes it to a more Vader-y red.

This thing might just be the closest we'll ever get to a real lightsaber in our lifetimes.

Okay, so you can't really have a lightsaber duel with this thing. But it does really retract as you turn down the flow of gas. And can it cut? Oh yes, the Hacksmith lightsaber can cut.

It takes a bit longer than, say, Qui-Gon Jinn taking down a Trade Federation's door, but it does get the job done.

Let's face it, a lightsaber might be a cool thing to have but it's the practical applications are few without an evil empire to overthrow.

I mean, I get it. I want a real, working lightsaber, as much as my limbs probably don't want me to have it.

But it's just not going to be a priority for the world's great technical minds, so not many engineers out there are even working on lightsaber technology. Hacksmith's lead engineer, James Hobson, said he could "count on one hand the number of people working on lightsaber tech."

Check out the full build in the attached video!

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