An elegant weapon for a more civilised age?
Or so says Obi-Wan as Luke opens a lightsaber for the first time and wields it with somewhat haphazard skill. You know the scene. You’re kind of relieved that Luke’s holding the sabre the right way up as he schvrmmmmmms the blade through the darkness of Obi Wan’s hut on Tattoine. You imagine yourself holding the sabre, feeling its weight in your hand, lunging forward with grace, poise and that sound. Not as clumsy or as random as a blaster, Obi Wan observes, and that’s the beautiful thing.
Disappointingly, however, the laws of physics mean you can’t actually use light this way – light simply travels on until it hits an object, so a controlled blade of this kind can’t exist unless you could confine plasma as a hot gas by means of a complicated magnetic field. Even if you could, says Professor Carsten Welsch, Head of Physics at the University of Liverpool and Head of Communication for the Cockcroft Institute, you also wouldn’t be able to see the blade of the sabre unless you looked directly into it -– ‘in which case it would probably be the last thing you’ll ever see.’