they have an astounding 3 or 4 layer one of these jobbies at the exploratorium. They have a what looks like a video projector above it so that they can
  • turn individual layers on and off
  • change layer colors
  • change motion, by means of adusting the phase and frequency of the light
  • blur
  • ajust each of these factors for each color channel
And there are two port holes in the side of the beast, so you can see the works.

While I was marveling the true identity of the Exploratorim occured to me.