The death ray is the logical equivalent of a six-shooter for a hard-drinkin', hard-fightin' space cowboy. In early science fiction pulps, any adventurer worth his space boots carried an old-fashioned holster containing a high-fashion ray gun—and the more stylish the fins, the better. The hardware is now available for us to emulate our cosmic heroes.
Ray-gun-like weapons are quickly becoming commonplace. Preliminary weapons are nonlethal and have been used by happy-go-lucky military troops and police officers eager to teach new dance moves to protesters and rioters. Several classes of directed energy weapons, called nonkinetic weapons by military types, have met field trials and are coming into widespread use.
The Active Denial System, developed by the Pentagon, can aim and emit superhigh-frequency microwaves. When the millimeter-size wave pulses hit human skin, they heat the body's water to the point of pain. The burning sensation has been compared to touching a hundred-watt lightbulb but without the singed hair—the system is only playing with your nerve endings, not causing permanent damage. Currently, the weapon won't fit in your holster—soldiers have to mount them on top of Humvees.
Alternately, why not use a prototype "lightning gun" to harness the Zeus-like power of electricity? A host of new defense contractors have sprouted to help governments battle terrorists, and they supply a variety of hair-raising weapons. Companies like Ionatron and Xtreme Alternative Defense Systems have developed competing zap guns. Both weapons use pulsed lasers to create a conductive path in the air away from the gun's barrel and then use a simple Tesla coil to generate a painful bolt of electricity. Both rifles are the size of a briefcase, weigh 25 pounds, and can shoot electricity wildly at 12 feet or consistently at 4 feet. Occasionally, the flashing purple discharge kicks back and lashes the bejesus out of the poor guy holding the gun.
We have so far ignored the most compelling directed energy weapon of all—the laser blaster. Jedi Knights can apparently use light sabers to easily deflect laser bolts, but electrically driven solid-state laser weapons (preferred over their less-wieldy chemical-based cousins) are designed primarily to zap approaching missiles. Field-tested military prototypes are pushing 25 kilowatts of power, and research is under way on versions that can turn missiles into swiss cheese with 100 kilowatts of laser power (a million times more powerful than an everyday laser pointer).
Meanwhile, the General Atomics company has developed a prototype weapon, called the High Energy Liquid Laser Area Defense System (HELLADS). Precise details are classified, but the system purportedly combines two types of laser, liquid and solid-state, for a single über-powerful weapon. Unlike other liquid lasers, the HELLADS can fire a continuous beam without a large cooling system, and unlike solid-state lasers, the HELLADS produces a high-energy density that does not require pulsing the laser on and off. The whole system weighs 1,600 pounds and can fit into the space of a large refrigerator. The project goal is to eventually spit a 150-kilowatt beam clean through enemy missiles.
The big question, of course, is what is keeping a handheld laser blaster out of your pocket? The most noticeable obstacle is heat dissipation. Operational lasers are inefficient, converting only about 15 percent of electric power into laser, with the rest wasted in the form of extreme heat. More efficient diodes (the part that converts electricity to light) would lower heat output and shrink lasers so that they could hang jauntily on your hip. For now, though, you will have to be happy with mounting military lasers to your tactical ground vehicle (that's your Buick).
This article is excerpted from Where's My Jetpack? A Guide to the Amazing Science Fiction Future That Never Arrived, to be published in April 2007. Copyright 2007 by Daniel H. Wilson, Ph.D. Printed by arrangement with Bloomsbury USA.