A device that essentially listens for light waves could help open up the last frontier of the electromagnetic spectrumâthe terahertz range.
So-called T-rays, which are light waves too long for human eyes to see, could help airport security guards find chemical and other weapons. They might let doctors image body tissues with less damage to healthy areas. And they could give astronomers new tools to study planets in other solar systems. Those are just a few possible applications.