The work is composed of two spheres, each of which contains another movable one. By handling them it is possible to simulate the succession of the six phases of the moon. The object seems to be the product of a nostalgic alchemist who proposes to measure the endless motion of two spheres, destined to chase each other without ever reaching each other. The title refers to the celestial geometries of which the undulating and elusive trajectories are contemplated. More than a fixed image, the work recalls a chain of images, evoking cosmic rhythms and sounds.