VIRTUAL-reality technology has the potential to become a tool to enhance the quality of life, a window onto invisible worlds, and a liberating force for good minds trapped in bodies diagnosed as dysfunctional.
But the technology also has the potential to become a dangerous brainwashing device or a form of imprisonment through illusion.
The full potential of this technology will take 10 or 20 years to manifest itself. Now is an ideal time for a widespread public discussion of the benefits and liabilities of virtual-reality-based applications.
Virtual reality creates the illusion of immersion in an artificial world or of presence in a remote location in the physical world. To enter virtual reality, a person puts on a head-mounted display. A pair of tiny television tubes, special optics, and a device that tracks the position of the user's head are mounted in the display so that when it is worn, the normal view of the outside world is blocked.
In its place is a three-dimensional depiction of a "world model" that exists in a computer. The display is linked to the computer, and the user's motions are transmitted to the computer, which updates the world model.
You can look behind objects to see what is there. You can look at the floor or the ceiling. You can zoom upward and look down on the scene.
Instead of seeing a depiction of an artificial world on a flat screen, the user is literally surrounded by the depiction. This "virtual world" can consist of a real or imaginary room, a city, a molecule, a solar system, the interior of a human body - anything that can be modeled by a computer.
A glove is also connected to the computer. The glove contains sensors that track not only the position of the hand, but the degree of flex of the fingers. When you wear a display and a sensor-equipped glove, you can see a depiction of a hand floating in the artificial space in which you are immersed. When you move your hand or wiggle your fingers in physical space, you see the hand in artificial space move and wiggle in exactly the same way.
Acoustic spaces can also be simulated and add to the power of the illusion of being in a place that exists only inside a computer. It is also possible to use electromechanical, hydraulic, and pneumatic equipment to simulate being acted on by a force, to feel the texture of objects, and, to a limited degree, to feel the shape of objects.
The use of virtual reality as a scientific visualization tool is enough to guarantee its place in history. The microscope made biology and modern medicine possible, because it gave scientists a window onto the world of the very tiny. The telescope helped create the foundation for the Renaissance by offering a window onto the world of very distant objects, thus changing our image of humanity's place in the universe.
Virtual reality offers another window, but one that a scientist can climb through to interact directly and bodily with scientific abstractions: Virtual reality has the potential to become a microscope for the mind.
At the University of North Carolina at Chapel Hill, I used a force-feedback mechanical arm and display to manipulate molecules as if they were Tinkertoys. I could use the arm to try to fit the molecules together like pieces in a puzzle and feel the molecular forces as actual physical resistance.
Had I known anything about chemistry, the virtual reality model could have served as an intuition-amplifier, helping me solve hard problems and making other problems visible. Other scientific visualizations make it possible to interact similarly with the weather, the airflow over an airplane's wing, and with any complex phenomenon that a computer can model.
Computer-aided design revolutionized architecture and helped drive the development of high-performance graphics workstations. Virtual-reality-aided design could act in a similar manner.
In Japan, Nippon Telephone and Telegraph has developed prototypes for three-dimensional videotelephones. Outside Kyoto, a consortium of Japanese companies is devoting $50 million to research into virtual reality as the basis for a communication medium of the future.
Fujitsu has plans to make virtual-reality home entertainment as ubiquitous in the 21st century as Nintendo computer games are in the late 20th century. Fujitsu is targeting entertainment, education, and training as three key markets for a technology that will enable people to step into their own fantasy worlds and enable students to learn by doing.
Other entertainment giants - Disney, Philips, LucasFilms - are quietly looking into the possibilities. Considering the role consumer electronics has played in driving industries based on electronic technologies, the entertainment potential of virtual reality alone could act as a powerful driver of future virtual reality development.
The use of virtual reality to extend the senses, the sense of mobility, and unlock the mental capabilities of quadriplegics constitutes a field in itself. Within the next year, diagnosticians working with the University of North Carolina expect to see prototypes of real-time "magic spectacles" that will enable them to view three-dimensional structures inside the human body.
Questions of power and control are always important when technology creates a new entertainment or communications medium: Will there be a market for realities, or will we all have to buy "regulation" reality from Fujitsu or Disney? The issue of whether virtual reality will be an open system or a proprietary one might be one of the most important questions the technology faces.
Such questions can only be answered by an informed citizenry. That is why it is important that people learn to talk more intelligently about a future in which it might be possible to manufacture any conceivable experience.