Looks like the Department of Defense finally has its directed energy weapon. Christened the Active Denial System, the weapon uses beams of electromagnetic energy to heat water molecules just below the skin to 130 degrees in less than a second. End result: astonishing pain. "It tricks the pain sensors into thinking they're on fire," said Air Force Research Laboratory spokesman Rich Garcia. Garcia should know. He was among hundreds of volunteers on whom the device was tested. "They did a full body back shot," he explained. "It hit in the small of my back first. For the first millisecond, it just felt like the skin was warming up. Then it got warmer and warmer and you felt like it was on fire. ... As soon as you're away from that beam your skin returns to normal and there is no pain. I thought to myself, 'Why you wimp. You know it's not causing any damage. You'll be able to override it.' Each of the next three times, I was on there a little bit longer. The fourth one was the longest. It was about two seconds. It felt like my hair was on fire."