Exploratorium Exhibits - Rental Group C
The Zoetrope was invented in the mid-1800’s, long before the development of the
movie camera and animated cartoons, as a way of deriving motion from still pictures.
Look through the slits at the drawings and turn the crank at the side of the exhibit
as fast as you can. Turn the crank the other way and notice that the balls roll in the
opposite direction. As the cylinder rotates, you see a fragment of the picture on the
far side of the cylinder. When the next slit passes your eye it reveals a slightly
different part of the picture. Each image lingers in your eye and brain long enough
to merge with the next image. This phenomenon, called persistence of vision,
creates the illusion of a continuously moving picture.
With Afterimage, visitors experience the way an image stays with us long after we
have seen it. Visitors look into the viewer and push a button, causing a bright
strobe light to flash behind a slide with images of a circle and a cross. These patterns
are visible for up to fifteen minutes. Remarkable color changes, shape disintegration,
and movements can also occur during the life of the after-image.
Aurora shows how reflections are created by both the shape of the light and the
shape of the reflector. This reflector is a large curved sheet of brushed stainless steel.
The ridges in the steel act like tiny mirrors, each reflecting an image. When the
images from all the ridges add up, they blend into a single elongated image that
looks like a ribbon of light. The many-colored tiles of the exhibit allow visitors to
experiment with both the shape and color of the reflections.
Bicycle Legs is a mechanical representation of human legs applied to the task of
pedaling a bicycle. Each leg is powered by two air cylinders, which represent the
two major leg muscles. Visitors can activate each of the four cylinders separately. By
carefully timing the activation of the cylinders, it is possible to set the legs to