This question wasn't identified anywhere else on the site, so I thought I would ask it. Lightsabers are (seemingly) closely related to plasma, which would be the closest tangible thing to a lightsaber in the modern world. Given the fact that a lightsaber would be a constricted plasma arc, it could reach temperatures of up to 25000°C. Wouldn't a lightsaber end up melting a person?

No? Okay. What about lightsaber fight scenes? Plasma cutters reach up to 800 Amperes, and that's a smaller sort of plasma arc. You need specific eyewear for these plasma cutters because it can cause eye damage relatively quickly. These are three entire feet of constricted plasma. Wouldn't these lightsaber fighting scenes make Jedi go blind relatively quickly?

2 Answers 2


First, a Lightsaber's power source is Kyber Crystals.

A kyber crystal, simply known as a kyber, also called a lightsaber crystal, the living crystal and known in ancient times as a kaiburr crystal, were rare, Force-attuned crystals that grew in nature and were found on scattered planets across the galaxy. They were used by the Jedi and the Sith in the construction of their lightsabers. As part of Jedi training, younglings were sent to the Crystal Cave of the ice planet of Ilum to mine crystals in order to construct their own lightsabers.

- Wookieepedia -

There is a YouTube experiment done by HackSmith Industries channel, and they have created a prototype Lightsaber using Plasma. The second video shows them experimenting how it will destroy other objects. There, the wielder actually wears a pair of goggles when operating the Lightsaber. Also, the Lightsaber is shown to have a burn effect, rather than just cutting through a surface like a stormtrooper's armor. Therefore, it appears to cause a blind effect on the wielder. In real world, it would be safe for its wielder to wear protective gear when operating a Lightsaber. But it would not melt a person, even if they are wearing Jedi attire.

That being said, we have to remember they are fictional weapons and they use to get a pass on the laws of Physics sometimes.

  • 1
    Okay, definite upvote + question answer. Yes, I know it is fictional, but I had to think of ti at some point. So the blind is a near-definite, but the burn is a no. Thank you!
    – WG481
    May 8, 2021 at 18:40

In the legends canon, lightsabers were so efficient that they would only really expend energy when cutting something. Such efficiency was achieved using materials such as force-imbued crystals and superconductors, hence why jedi-made lightsabers were always better quality and more efficient than non-jedi-made lightsabers (i.e. lightfoils).

What such an efficiency means, basically, is that the plasma and its containment field form a closed loop with the hilt, and virtually all the energy that goes out of the hilt comes back in unless the loop is broken. This is also in line with the current Disney Canon, where the containment field is so efficient that lightsabers emit virtually no light by themselves (at least much less than what burning plasma would normally yield), as can be seen in the Anakin vs Dooku battle.

In other words, unless you are actively cutting something, there's close to zero heat coming out of the blade, and the light is definitely not strong enough to blind anyone.

  • And yet Kanan and Ezra use their lightsabers for illumination in the krykna caves on Atollon (Rebels S2E12). May 9, 2021 at 8:41
  • @Geoffatkins - You mean ep21? And yes, they do. To little to no effect. The lighting doesn't change at all in the scenes where their lightsabers are off. Basically, the huge beams of natural light coming down from holes in the roof of the caves is what provides 95% of the lighting in those caves, not the lightsaber. Besides, I didn't say lightsabers provided no light at all, I said they visibly provided less light than expected from a plasma beam because the plasma is so efficiently contained.
    – Dungarth
    May 10, 2021 at 17:16
  • Yes, 21. Sorry, typo. May 10, 2021 at 17:18

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