The Pentagon has a laser that can identify people from a distance—by their heartbeat by David Hambling via @techrieview

It detects a person’s unique cardiac signature with an infrared laser. While it works at 200 meters (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.”

Wow - this is amazing.