From the website:
A dust cloud of silicon micro-spheres that was illuminated by laser light scattering from the cloud is suspended in a plasma. The dust cloud is approximately 0.5” high and floats in a conical shape between the dust tray and an electrode as long as the plasma is maintained. Fundamental dust cloud properties and dynamics have applications from plasma processing to space plasmas.
This work by Elle Starkman and Andrew Post-Zwicker of the Priceton Plasma Physics Lab won the 2005 Princeton Art of Science competition - can't wait till the 2006 winners are chosen!
Link: 2005 Gallery of Art of Science Competition