T-Rays: The Future of Airport Security, the End of Suicide Bombers?

Experiment helps scientists detect chemicals long-distance.

ByABC News
July 19, 2010, 2:19 PM

July 21, 2010 — -- It's the price we pay for living in a post-9/11 world -- waiting on endless lines at airport security, worried about missing a flight, and wondering if all those metal detectors and pat-downs will make us any safer anyhow.

Scientists at Rensselaer Polytechnic Institute in Troy, N.Y., have now made an advance that could substantially change that scenario. Instead of X-rays, try T-rays.

T-rays? Sounds like a dinosaur or something from a high-school cafeteria, but it's really slang for terahertz -- part of the electromagnetic spectrum, like visible light, infrared or ultraviolet -- that could be tremendously useful in remote sensing involved in everything from homeland security to defense to medicine.

The scientists at RPI have now used terahertz sensing to determine the chemical makeup of samples in the lab from up to 67 feet away -- the size of the lab in which they were working -- and say their technology may be effective at considerably greater distances.

Imagine, scientists say, being able to:

"A lot of chemical compounds have chemical signatures in the terahertz range," said Jingle Liu, one of the members of the Rensselaer team, who published their results in the journal Nature Photonics. "We tested hundreds of compounds."

For years, T-rays were the stuff of spy thrillers -- witness this 1996 excerpt from Tom Clancy's "Games of State:"

"He pressed a square, red button on the back of the power pack. 'What you get are terahertz oscillations that wriggle around between the infrared and radio wave area of the spectrum. What that gives you is the ability to tell what's inside or behind something thin -- paper, wood, plastic, almost anything.'"