Padilla hopes to use engineered materials to investigate what he calls «
the last unexplored region of the electromagnetic spectrum» — the T - ray, or terahertz, region — positioned between the infrared and microwave bands, at a frequency of a trillion cycles a second.
«Between 10,500 and around 5,550 years ago, it was a good place to live,» says Stefan Kröpelin, a geoarchaeologist at the University of Cologne in Germany, who has spent the
last 30 years leading excavations in the eastern Sahara, a
region that until recently has been largely
unexplored.