Francisco de Goya paintings

Francisco de Goya paintings
Filippino Lippi paintings
guns, knives, coins, or even plastic explosives — will return stronger signals. Advanced software and computers can process these signals and convert them to images in which the hard objects are clearly outlined.The company claims that the three-second exposure to the machine's X-rays aren't any more harmful than the natural exposure to radiation that most travelers experience in 20 seconds of flight on a conventional airplane.No Harm HereOther companies are working on similar imaging technologies that don't use harmful X-rays. Trex Enterprises, a company in San Diego, is testing a so-called passive millimeter wave camera with the National Institute of Justice, the research arm of the Justice Department. Much like an infrared camera, the Trex device can detect hidden objects by measuring differences in invisible heat energy emitted by a person's body and the concealed object.