The light saber is the iconic object of the Star Wars Universe. We could argue that Star Wars wouldn’t be what it is without it. It is a fantastic piece of true science fiction that helps both ground the Jedi/Sith characters in historical lore, yet give them a way to push the boundaries of what a typical sword can do.
I’ve had many arguments with my friends about how the Light Saber isn’t possible. Dr. Michio Kaku, a well known physicist, seems to disagree, somewhat. In the following video, he discusses more about current cutting edge technology that would enable a light-saber like device.
This description is awesome, but also a bit of a compromise. This modified plasma torch would be some kind of weapon (or tool), but wouldn’t be the portable, versatile, solid object that we know. The element that makes this object solid, hot, and capable of cutting open holes in star ships isn’t really covered. There are very specific things shown in the films that a light saber can do and the device posed by Dr. Kaku doesn’t quite measure up.
But it’s still cool.