writes: British scientists working at ThruVision have created a camera capable of detecting weapons, illigal substances, and other threats from a distance of 25 meters. Just like all its sister devices, it uses electromagnetic waves, however the wavelength given for the unique Terahertz rays that they use are rather vague (between 1 millimeter and 100 micrometers). Unlike the wavelengths used by other devices, T-rays have another advantage along with their range and relative harmlessness to health:
T-rays travel through many non-conducting materials including cloths, wood, plastic, fog, and walls. Depending on the material, the signature of the wave is different, so that explosives can be distinguished from a block of clay, and cocaine can be distinguished from a bag of flour.