Greg Hoff, age 10, of Indianapolis, Ind., for his question:

WHAT IS A HOLOGRAM?

A hologram is a pattern, usually made on photographic film, which can produce a three dimentional image of a scene. The holographic image is often so lifelike that it seems to be a real scene viewed through a window. The viewer can see around objects in the foreground by moving his head, just as he looks around real objects.

A hologram can be produced by illuminating the scene with lights from a device called a laser. The holographic image is then created by shining a similar beam of light on the hologram.

The laser lights that are projected on the hologram are actually changed to reconstruct the light patterns which came from the original scene.