via Posthuman Blues and New Scientist

The night sky could soon be lit up with gigantic three-dimensional adverts, thanks to a Japanese laser display that creates glowing images in thin air.

The display utilises an ionisation effect which occurs when a beam of laser light is focused to a point in air. The laser beam itself is invisible to the human eye but, if the intensity of the laser pulse exceeds a threshold, the air breaks down into glowing plasma that emits visible light.

(Credit: AIST)