Close Encounter With `Virtual Reality'

IF I turn my head to the left, I can see the Cheshire Cat. If I extend my hand and reach in front of me, I can touch the Mad Hatter. I am in Alice's Wonderland. Neither dreaming nor hallucinating, I am really sitting on a stool in a booth at a computer graphics show in Boston.

The cause of my fantastic view is the helmet on my head. In front of each eye is a tiny television, each connected to a computer that is displaying a scene from its memory bank. A device on top of the helmet reports changes in my head's position to a controlling computer, which instantly updates the pictures. A special glove on my hand tells the computer the position of each of my fingers, so when I raise my hand, the computer can draw it.

Inventor Jaron Lanier calls the system ``virtual reality,'' and his company, VPL Research Inc., in Redwood City, Calif., is making a lot of heads turn. Not limited to Wonderland, the computer can be programmed to display any ``world'' imaginable. Wearing the headset, an architect can literally walk through a computer simulation of a building under construction and observe first-hand how things will look. The National Aeronautics and Space Administration is exploring ways of using the system to control robots in space.

To the person wearing the helmet, the virtual world appears ``completely real,'' says Mr. Lanier. ``It's like being in a dream. You can hold up your hand and wriggle your fingers, and there is another version of your hand'' in the computer screen, doing the same thing.

What's more, when two people don the helmets and gloves, the computer can be programmed to let them see each other.

VPL may soon install a system in a hospital for children with disabilities, ``so they can leave their disabilities behind and interact with others on the same level,'' says Chuck Blanchard, a VPL programmer.

Beyond the headset and gloves, the company makes a full-body suit, although at $92,000, none of them have been purchased yet. Indeed, high cost is one of the real remaining barriers to virtual reality. Together, the helmet and a single glove cost $17,800; add in the two computers required to control the two TV screens, and the cost jumps to over $200,000.

And the system still has problems: The virtual world lags behind a person's head movements by a quarter of a second or so, and the images displayed inside the headset currently look more like pages out of a child's coloring book than high-quality computer graphics. Nevertheless, as the graphic systems get faster and more realistic, these problems should, like the Cheshire cat's grin, disappear.

And, with the cost of systems tumbling, the day may soon arrive when people take vacations to other planets simply by donning full-body suits and helmets.