Welcome to virtual reality.

During the last two years, I have talked about the virtues and vices of new technologies on many radio talk shows and before live audiences. The public always gets the most excited when I discuss virtual reality. Let us see why.

Perhaps you would like to visit Victorian England and shake hands with the legendary Sherlock Holmes? Raft past blood cells in the human body's circulatory system? Or swim amidst Tahitian coral reefs and fish without leaving your office? A rapidly growing technology called virtual reality gives new meaning to these daydreams.

Virtual reality (VR to people who use the technology) focuses upon our senses, not our vocabulary. So let us begin our adventure with a field trip.

Imagine putting a helmet on your head and slipping a glove on each hand. The helmet blocks out all the lights and sounds from the "real" room where you are reading this article. The helmet (also called a head-mounted display) is equipped with two visual screens, each the size of a half-dollar. One screen is positioned in front of each of your eyes. The images on those screens are programmed by a computer. Similarly, the inside of your helmet is encircled with small audio speakers. Each speaker is controlled by the same computer. It's as if you have literally stuck your head inside a computer monitor or a television set. In addition, your body has joined you inside the computer. Your helmet and gloves are wired with sensors to detect how you physically respond to the pictures on the tiny screens and the sounds on the little speakers. Whenever you rotate your head, the computer takes note. Each time you flex your fingers or twist your wrist, the computer calculates the angles and velocities of your motion.

Welcome to the doorstep of "virtual" reality! All your equipment is in place. Once we turn on the computer, we will open the door and make one of your fantasies come true.

Assume that you desire to meet Sherlock Holmes. The computer-coordinated screens and speakers put you inside his Baker Street office. You can view the hands on his grandfather clock, just as you can hear the clock chiming a new hour. You can almost smell Holmes' pipe tobacco, though he is still invisible. Turn your head to the right to look for him. The computer feels your head swivel and readjusts the visual screens so you see different scenery as your head rotates. There he is - Holmes is warming himself in front of the fireplace. As you extend your arm to shake his hand, the computer quickly adjusts the screens. You can see your hand move toward him and, soon thereafter, touch Sherlock's hand. He is glad to meet you, and he asks you questions about future technologies that might aid his criminal investigations.

On one level, the above Holmes rendezvous is common. Novelists, poets, and playwrights have enlarged and enriched our imagination for centuries. Millions of people watch and participate in elaborate fantasies on such TV shows as "Star Trek" and at the movies. On another level, VR provides a unique one-to-one relationship between person and machine.

What is virtual reality from a technical standpoint? VR is, first and foremost, a computer system. This computer hardware and software fuse graphics with a database in order to simulate a given "world" The most famous VR is probably the flight simulator used by airline companies and the military to train pilots. This system blends graphics (manipulable computer images of clouds, airports, mountains, and so forth) with a database (stored computer details about flight patterns, landing gear, radar readings, and the like). The final product is a cubicle in a warehouse that looks, feels, and operates as if it were an airplane cockpit.

How does VR differ from other computer graphics? Virtual reality, unlike a full-color Lotus 1-2-3 spreadsheet or a Wordperfect document, conveys multisensory information. VR links sight, sound, and touch. Also, VR is interactive; a VR user can manipulate objects on the screen with the relatively recent invention of gloves, or with more familiar computer accessories such as a mouse or a joystick. VR connects the computer system to the human muscular and nervous systems.

The term virtual reality was coined in the mid-1980s by Jaron Lanier, now a high-tech cult figure based in Sausalito, California. In 1984, Lanier founded VPL Research, Inc., in Foster City, California. This company was the first to focus on VR products. VPL Research has invented and manufactured key VR equipment such as the trademarked DataGlove, DataSuit, and EyePhones.

You can see photographs of VR equipment in Ken Pimentel and Kevin Teixeira's nontechnical book Virtual Reality: Through the New Looking Glass. You can read further research details in Howard Rheingold's popular book entitled Virtual Reality.

Today, governments and corporations around the globe are vying to use VR. The Pentagon's Defense Advanced Projects Agency is trying to cope with dwindling defense budgets. Therefore, they have built a battle simulator complete with flying shells and ear-splitting explosions to train soldiers at less cost than traditional war games. Chrysler and IBM are jointly using VR to design autos quicker and cheaper. Fujita Corporation, a Japanese construction firm, is trying to implement telepresence - the remote manipulation of equipment. Working with Lanier's VPL Research, Fujita hopes to create a spray-painting robot that will enable a Tokyo operator to paint buildings anywhere in the world. Vice-President Albert Gore is aware of VR's promise; he deems it critical to "the way we design new products, teach our children, and spend free time."

Future VR applications seem limited only by our imagination and hard work. A heart surgeon in Houston might use VR telepresence to operate on a patient in Kansas City. A therapist might create a VR environment to treat a patient who suffers from, say, a snake phobia; the patient could be coached to deal with snakes step by step from a safe distance. A detective novelist might write interactive novels in which the reader can play out various scenarios. A chemistry teacher might illustrate atomic bonds by letting his or her students ride atop a carbon atom as it approaches an oxygen atom.

Entertainment is an arena with enormous potential for VR. At Chicago's North Pier, there is a VR game site called BattleTech Center, which has sold hundreds of thousands of tickets since it opened in 1990. People pay to sit in control pods where they battle one another in futuristic war zones. Nintendo sells a VR Powerglove for about $99 that lets video-game players use hand gestures. Both the BattleTech Center owners and Nintendo plan to expand.

This is just the start of a VR-based entertainment revolution. The day might come when television is replaced by VR and whole new fields of interactive home entertainment are thrust on us - for better or for worse.

Along with all other technologies, VR is a double-edged sword. Already, controversial ethical issues have emerged in its use. Here are two examples. First, in 1991-1992, San Francisco porn-movie king Jim Mitchell was tried for the murder of his brother. The prosecutor showed the jury a computer "simulation" of the murder based on the opinions of a ballistics expert; of course, the film implied that Mitchell was guilty. This was the first-ever use of virtual reality as courtroom evidence. Coincidentally, the trial took place near the studios where film producer George Lucas (Star Wars) creates his fantastic celluloid illusions. Mitchell's attorney called this VR technology "wizardry that has no place in a court of law." Would you like Hollywood special-effects experts to create "evidence" against you?

Second, some employers want to use VR to screen potential employees. Suppose somebody develops VR that simulates various police emergencies; is it fair to evaluate police officers by how quickly and accurately they push buttons in response to VR burglaries, family disputes, or car chases? If such employment tests become common, I suspect that there will soon be training schools that teach people how to play VR games.

There is another dark side to VR. Millions of people today already live dangerously vicarious lives; they spend "virtually" all of their free time addicted to computer, cinema, or television screens. Too many of these persons are socially apathetic at best and sociopathic at worst, as they barely know or care about the difference between electronic dots on a screen and human beings on a street. What do we gain by making electronic media even more seductive? I recently attended a conference with a prominent VR commentator. He confessed to me, "At first, Andre, I was excited by VR. The more I get beneath the surface, the scarier it gets."

Scientist Andre Bacard is the author of Hunger for Power: Who Rules the World and How. A guest on hundreds of radio talk shows, he can be reached at Box 3009, Stanford, CA 94309.