Terahertz spectrum scanning is potentially ideal for finding bombs due to the sheer range of materials it can detect, but it's not exactly practical for luggage checks when you need both a suitcase-sized machine and up to half an hour to conduct a scan. MIT researchers have a better way, though: they've developed a quantum cascade laser system that should make terahertz detection a reality. Since the laser's single, tiny frequency comb only consumes power for very brief periods, you can fit it into a part the size of a chip without a gigantic cooling unit -- perfect for airport scanners. It takes as few as 100 microseconds to identify a substance, too, so you wouldn't have to wait (longer than usual, anyway) while agents scan your bags.