Scientific American has a great feature on Star Wars, coinciding with the imminent release in US theatres of the animated Clone Wars film. There is also an interview with Jeanne Cavelos, author of The Science of Star Wars, canvassing xenobiology, cloning, robotics, human survival on a range of exoplanets with varying conditions, intergalactic travel, and laser weaponry:
What about laser weapons? Are we any closer to having those, and are they realistic?Who wouldn’t want to have a blaster? They are so cool. Right now we have low-powered lasers than can blind people, or higher power ones that burn skin or clothing—kind of like a long-distance flamethrower. The most powerful lasers we have that I know of have about 2.2 megawatts of power, which can destroy enemy missiles from thousands of miles away. These are rather similar to what we see in Star Wars.
But for these lasers we need enough equipment to fill up a truck or even a building. We can’t exactly fit this laser technology into a holster just yet. The best lasers are still only 30 percent efficient and the rest of their energy is lost as heat. You also have to cool the laser down to keep it working properly, plus you need to put a lot of power in to get a lot of power out.
There are wireless TASERs now about the size of a flashlight. They send out an ultraviolet laser beam that breaks up air molecules between them and the target. This releases ions, and then electricity can be sent through the air to knock someone out, or even give them a heart attack if you’re not careful. It’s kind of similar to when Princess Leia was stunned by the storm troopers near the beginning of the first movie [Episode IV: A New Hope]. There are also prototypes of stun grenades that superheat moisture in the air, which makes an explosive flash and bang that can stun people.
Cavelos also sheds light on The Force and the logistics of light sabers. You can read excerpts from The Science of Star Wars here.