system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Do lightsabers work underwater or in a vacuum?
gpt
Since none of their components relies on oxygen to operate, a lightsaber would almost certainly work just fine in a vacuum, though it wouldn't seem quite the same without the trademark hum.

Most lightsabers are vulnerable to water, however; the crystal circuit can easily short out when submerged. However, an ancient modification from the early days of the Jedi order was known to circumvent this problem. Amphibious Jedi Master Kit Fisto was the first to rediscover it, finding that a bifurcating cyclical-ignition pulse (a quick-change circuit that continuously alternates drawing its power from two separate crystals) could prevent his lightsaber from shorting out underwater.

When he added this knowledge to the Jedi holocrons it became a common modification among the Jedi generals in the clone wars, who frequently had to command on very wet worlds. One such lightsaber was Anakin Skywalker's, and Luke studied its design and later replicated it in his own green saber. By the time he founded the New Jedi Order, crystal pulse bifurcation was standard on all new lightsabers constructed.