Light Painting
Imagine reaching into the sky and plunging a dip pen into the phosphorescent arcs of fireworks streams, then painting across the sky. In lieu of the pen, use the camera lens to stretch these colors into swirls and sweeps, gushes and drizzles. This technique is called painting with light and occurs when a light source is in motion while taking a long exposure photograph.
(photographs taken of fireworks over Governors Club in Chapel Hill)