Is It the Light or the Shadow?

I wandered through the MADI Museum and Gallery, in Dallas, over the weekend, delighted and  amazed by its calculated yet playful collection of works.  Modern, geometrical, often vividly colored pieces, virtually all with moveable parts begging for interaction.  Extend an armature here, change shapes, colors, patterns and shadows there. 

The art and science of challenging the brain, of triggering cause-and-effect, in any discipline, is awesome!