The boffins at the US Department of Defence are always working on some sort of new weapon. One of its current projects is something to do with “talking lasers,” beams of light that can send audible messages–spoken words, for example–across short distances.
This non-lethal weapon works by creating a ball of plasma that is hit by a laser to make it oscillate. That creates sound waves.
What kinds of messages might these lasers transmit? How about “Stop or we’ll shoot you dead.”
Read more here.