Ivan Moscovich created these harmonograms with a twin-pendulum Harmonograph. The spirals, ellipses, and figure eights are graphical records of the swinging pendulums. Patterns of this sort—depicting two simultaneous oscillations in two dimensions— are known as Lissajous figures. Each pattern captures a record of the pendulums’ motions: The bigger the swing, the larger the figure; the slower the oscillations, the closer together the lines. As the swinging dies away, the trace shrinks.