Are you seen painting. Ofc yes, who would have not seen. But I am asking about Painting on Air/Space? Yes!! I am not joking. The following photo is an example. This was taken in our room with full darkness and my thimmi is writing a loving heart in air and I captured this with my cam.. The concept is called as Light painting.
Aperture: F/3.8, Shutter: 8 sec, Focal length: 18 mm
One more example with same exposure values:
Get more technical information: http://digital-photography-school.com/blog/slow-shutter-shoot-out-3-slow-shutter-speed-techniques/