Caustic Lion

Caustic Lion is a sculpture that invites the observer to discover a hidden message painted in light. A vertically arranged aluminum plate is engraved to recreate the delicate structure computed by a mathematical algorithm. After being hand polished to give it a mirror shine, the surface nearly becomes like a water surface frozen in time. When light rays reflect off the plate, they are deviated from their original trajectory to form a caustic, a light image that reveals a drawing of a lion. This effect is surprising, since no resemblance to this image is revealed in the plate itself, even though a precise mathematical relation exists between the drawing of the lion and the seemingly randomly undulating surface of the plate. However, this relation is so complex, that it can only be discovered algorithmically and can only be fabricated with high-precision CNC milling.
The observer can now make the hidden image appear, simply by shining a light onto the aluminum plate from the right angle. As the light source is moved, the caustic image morphs into new patterns of light, creating a playful interaction that stimulates exploration.
The surface of the aluminum plate was computed by Rayform SA based on an algorithm developed at the Geometric Computing Laboratory of EPFL. It was fabricated at EPFL.