Lightsabers: Why We Don’t Have Them (Yet)

It is the most elegant weapon for a more civilized age. A blade of pure light that cuts through blast doors, hums with magnetic dissonance, and retracts into a handheld hilt. But why, 50 years after A New Hope, can I not buy one at Walmart? We have lasers. We have plasma cutters. We have magnetic fields.

The problem isn’t the blade. The problem is the Battery.

The Energy Problem

To cut through a steel blast door in seconds (like Qui-Gon Jinn), you need roughly 1 Gigawatt of power. For reference:

• A lightning bolt is about 1 Gigawatt.
• A nuclear power plant produces about 1 Gigawatt.

A lightsaber hilt is the size of a flashlight.

• Energy Density: There is no known battery chemistry in the universe (except maybe the fictional Kyber crystals) that can store that much energy in such a small space without detonating like a bomb. If you short-circuited a real lightsaber battery, you wouldn’t get a spark; you’d get a crater.

Robots and the Battery Limit

In robotics, we fight this same battle every day (though with less risk of nuclear explosion). We want our robots to be faster, stronger, and run longer. But we are limited to a 12V NiMH or Li-Ion battery. This battery is our “Kyber Crystal,” and it is frustratingly limited.

1. Voltage Sag (Brownouts)

If you draw too much power at once—for example, accelerating all 4 motors and spinning a flywheel simultaneously—the battery can’t keep up. The voltage drops (Sags).

• Result: The 12V supply drops to 9V. The robot’s brain (Control Hub) needs 7V to stay awake. If it dips too low, the robot reboots. Ideally, your robot just fainted in the middle of a match. This is exactly what happens when a lightsaber flickers—except for us, it means losing the game.

2. Capacity Budgeting

We only have 3000mAh (Milliamp-Hours) of energy. We have to budget it like money in a bank account.

• “We can afford to run the high-speed intake.”
• “We CANNOT afford to stall the motors against the wall.”

Containing the Plasma

The other issue with Lightsabers is physics. Light doesn’t just “stop” after 3 feet. A real laser beam goes on forever until it hits something. To make a lightsaber, you are actually containing Plasma (superheated ionized gas) in a magnetic loop.

• The plasma leaves the handle.
• A magnetic field curves it back down into the handle.
• This creates a closed loop.

This requires powerful electromagnets—which, again, drain your battery instantly.

Conclusion

We are getting better batteries (Solid State, Graphene), but we are still far from Jedi levels. Until then, robotics teaches us efficiency. Since we can’t have infinite power, we optimize. We make lighter chassis. We use efficient code. We grease our gearboxes. We can’t brute force physics with a Lightsaber, so we have to outsmart it with Engineering.