Images: What 'Star Wars' tech is real?

What makes space opera work is a romantic adventure and a merry chase through the stars. What makes Star Wars work as a swashbuckling space opera are lightsabers. (Where would the franchise be without that climactic scene between Darth Vader and Obi-Wan Kenobi?)

Alas, based on our current understanding of physics, lightsabers remain fictional. For one thing, light beams don't simply decide to halt in their tracks after 2 or 3 feet.

Still, that hasn't stopped speculation about how similar devices could work. One wag has written a lengthy article saying a lightsaber could use glass filaments that extend when gigawatts of laser energy (stored in an as-yet unknown type of battery in the grip) are pumped through as it's turned on.

EXN.ca has interviewed Marc Nantel, the head of the Laser Micromachining Facility at Photonics Research Ontario, a government institute. Nantel says it's possible to create two converging beams of laser light that end at a single point. The only problem: It could harm its wielder if reflected off of a concave surface such a spoon. "Don't use the weapon in a kitchen," Nantel warns.