The Pentagon has a laser that can identify people from a distance — by their heartbeat — MIT Technology Review — “A new device, developed for the Pentagon after US Special Forces requested it, can identify people without seeing their face: instead it detects their unique cardiac signature with an infrared laser. While it works at 200 metres (219 yards), longer distances could be possible with a better laser. ‘I don’t want to say you could do it from space,’ says Steward Remaly, of the Pentagon’s Combating Terrorism Technical Support Office, ‘but longer ranges should be possible.’”