Liquid Things, a research group at the University of Applied Arts, Vienna, invited us to speak at a conference on fluid dynamics in the arts. Our talk was followed by a two-week residency during which we developed a new artwork, Photonic Wind, with the generous support of Tobias Nöbauer at the quantum optics department of the Atom Institute.
For over a decade, we had been dreaming of creating an artwork exploring optical levitation. Coincidentally, among the earliest experiments with photophoresis (light-induced migration of matter) were conducted in Vienna by iconoclast physicist, Felix Ehrenhaft, during the 1910s - 40s. Unfortunately, due to an argument concerning these experiments, with his colleague, Albert Einstein, Ehrenhaft was nearly erased from the pages of history. Based on his observations of light-guided silver powder in a vacuum chamber, Ehrenhaft proposed to Einstein a theory of “magnetic current”. Einstein was so dismayed by this concept that he put an end both to their friendship and to Ehrenhaft’s career. Nonetheless, magnetic current was eventually proven to exist in 2009, upon the detection of magnetic monopoles in a substance known as spin ice: http://www.nature.com/nphys/journal/v7/n3/full/nphys1896.html.
Our initial experiments followed in the footsteps of Ehrenhaft, however, substituting focused sun light with a powerful laser beam. For the next series of experiments, instead of silver, we levitated diamond micropowder, which was much easier to propel, attract, trap and guide along optical vortices. Depending on the laser’s angle and proximity, the diamond dust would alternate between surging starry jets and languorous vortical clouds. The latter experiments comprise the real-time video documentation; the still image is a photograph of the initial silver dust experiment.