"It's a lot nicer if you don't have to walk up to a bomb to find out what it is," quips Larry Senesac of Oak Ridge National Laboratory in Tennessee. I would have to agree: roadside bombs are clearly no fun for anyone. That's why Senesac and his fellow researchers have developed a laser system that can detect bombs from a distance of up to 100 meters. And that's not all — they say their special laser gun could also guard against food poisoning.
By sending out pulses of infrared light, the Oak Ridge laser system can pick up clues about the composition of the materials surrounding it. When the light pulses hit objects, they refract off of those objects, and some of the light is directed back at the laser system itself. Quartz crystals in the laser system transform these light pulses into a full picture of the chemical composition of the objects you want to check out. If the object's activation profile contains chemical signatures of known explosives, you've identified your bomb.
Using this technique, the researchers' laser gun might eventually be used to detect the chemical signatures that exist in spoiled food. One day, you might have a small laser in your cell phone, which you can whip out at the grocery store to get the best possible produce. As laser technology improves, so will this system; researchers are hoping that sensitivity will go through the roof as cost and size shrink accordingly. Three cheers for not exploding, and for always finding the greenest banana of the lot!
Ray Gun Detects Bombs at Distance [Discovery Channel]
Image of ray gun by ImageZoo