Rickey discovered the reverse knife-edge bearing, which allowed him to use blades that moved independently of one another. Sedge Themes was his first series exploring the formal possibilities of this technology. In another work that uses this bearing device, Bubble Chamber I, from 1962, alternating blades are fixed to a wall as pendulums, weighted so that they rest at acute angles. The playful lines pointing in all different directions hint at the activity of a bubble chamber—a device used in physics to heat liquid to the point of boiling and vaporizing, creating trails of microscopic bubbles that are used to measure the energy of charged particles.

from Kephart, Passages of Light and Time: George Rickey's Life in Motion (Notre Dame, 2009)