A camera that can see through clothes, skin and even walls without X-rays has been developed in what is being called one of the first great technological breakthroughs of the 21st century. Click to enlarge The "terahertz" camera, still in prototype form, is under rapid development by scientists in Oxfordshire. It is likely to have many applications, ranging from medical scanning to identifying concealed weapons on airline passengers. Unlike X-rays, it does not expose patients to potentially harmful radiation. Instead, it detects a form of ultra-high-frequency, or terahertz, energy waves naturally emitted by all objects. Nor does it require people...