This story was originally broadcast on March 2, 2008. It was updated on May 30, 2008.
What if we told you the Pentagon has a ray gun? And what if we told you it can stop a person in his tracks without killing or even injuring him? Well, it's true. You can't see it, you can't hear it, but as CBS News correspondent David Martin experienced first hand, you can feel it.
Pentagon officials call it a major breakthrough which could change the rules of war and save huge numbers of lives in Iraq. But it's still not there. That because in the middle of a war, the military just can't bring itself to trust a weapon that doesn't kill.
It's a gun that doesn't look anything like a gun: it's that flat dish antenna which shoots out a 100,000-watt beam at the speed of light, hitting any thing in its path with an intense blast of heat.
An operator uses a joystick to zero in on a target. Visible only with an infrared camera, the gun, when fired emits a flash of white hot energy - an electromagnetic beam made up of very high frequency radio waves.
Col. Kirk Hymes, head of the Joint Non-Lethal Weapons Directorate, is in charge of the ray gun which is being tested at Moody Air Force Base in southern Georgia.
The targets at the base are people, military volunteers creating a scenario soldiers might encounter in Iraq, like angry protestors advancing on American troops, who have to choose between backing down or opening fire. Off in the distance, half a mile away, the operator of the ray gun has the crowd in his sights.
Unlike the soldiers on the ground, he has no qualms about firing away because his weapon won't injure anyone.
He squeezes off a blast and the first shot hits like an invisible punch. The protestors regroup and he fires again, and again. Finally they've had enough. The ray gun drives them away with no harm done.
Officially called the "Active Denial System," it does penetrate the body, but just barely.
What happens when the beam hits a person?
"It's absorbed in the top layer, 1/64th of an inch, which is about three sheets of paper that you'd find in your printer," Col. Hymes explains.
"And it's hitting what inside that 1/64th of an inch?" Martin asks.
"Well, right within that 1/64th of an inch is where the nerve endings are," Hymes says.
You have to feel the ray gun to believe it, and there's only one way to do that. Martin, who voluntarily became a target, described the sensation of being hit by the ray gun like scalding water.
What makes this a weapon like no other is it inflicts enough pain to make you instantly stop whatever it is you're doing. But the second you get out of the beam the pain vanishes. And as long as it's been used properly, there's no harm to your body.