The ‘bat signal’ of the future: Free-floating laser images could be fired into the sky to alert people to disasters

Technology offers possibility to project messages into a cloudless sky

Scientists showed off spirals, fluttering butterflies and outline of an apple

Technology works by focusing intense laser light into a spot in the air

This makes the molecules there emit light that looks like a bright LED

Bursts of light come hundreds of times a second, and as the beam moves, form what appear to be a three-dimensional image

via Free-floating images are made by firing lasers and they could be used to alert people to disasters | Daily Mail Online.