exhibit consists a cylinder with a pool of water at the bottom containing
small live fish. The inside wall of the cylinder is vertically striped.
When the cylinder is slowly rotated the fish can be observed to
swim along with the stripes, which keeps their view of the surroundings
from blurring. Virtually all animals reflexively focus their eyes
on moving objects. Most animals can follow motion by moving their
eyes. But fish can't move their eyes very much, so they swim along
with moving objects to see their world more clearly.