A complex system of mirrors, floating in mid-air against the background of a cell-block.
It is actually a gigantic kaleidoscope, the permutations of which reveal the totality of all possible universes, and as such is also the sculpture of an angel, which are essentially kaleidoscopes praising God, although they can assume many forms. A gigantic kaleidoscope with connected spectrograph, radio telescope, a ground FM aerial, several genuine vacuum tubes, and a rebuilt prototype CCTV camera. It revolves around itself, and is powered by only the stripped and flayed nervous system of a dragonfly, embedded in an organic computer chip.
It is possible to build one using materials found on every well-stocked astral plane.