KENSINGTON -- The ultimate fantasy form of virtual reality is the holodeck on ''Star Trek: The Next Generation'' and its spinoffs ''Voyager'' and ''Deep Space Nine.'' (Holodeck is pronounced HOL-a-dek.)
Everyone who follows ''Star Trek'' knows that each starship has at least one holodeck, which is a kind of recreation room where the ship's computer can create, by means of holography and projected matter, any scene, complete with interactive characters. Starship crew members go to the holodeck for R&R; one character uses it for combat calisthenics, another for taking women on dates to exotic planets. In the ''Voyager'' series, the ship's doctor is a holographic projection.
The holodeck's synthetic reality is indistinguishable from the real reality. Its projected images even have solidity; holodeck bullets can kill, holodeck horses can be ridden, and projected people have personalities and even sexual capacity.
Pure fantasy, right? No such technology will ever exist -- except that it does exist, and it's closer than you think.
I realized the existence of holodeck technology while I was thinking about what I call ''virtual vantage,'' which is a computer-synthesized viewing vantage that might soon be available through digital television.
If enough video cameras are aimed at a scene, computers will be able to ''interpolate'' between the cameras to create synthetic viewing vantages. As Nicholas Negroponte points out in his book, ''Being Digital,'' we'll soon be able to watch a baseball game from any vantage, including that of the baseball. Viewers using joy sticks will be able to see the game from the pitcher's mound, or from 20 feet over second base, or from a slow glide across center field.
The scene I'd like for a virtual vantage is in Monument Valley in Arizona. If I were as rich as Bill Gates, I'd install continuously
operating cameras and microphones at the place I have in mind. The cameras would have a clear view of everything including the sky and horizons, and the microphones would pick up sounds of wind and animals.
Information from the cameras and microphones would be sent at high speed to a computer-driven television in my house on the east coast. Using stereoscopic TV goggles and stereophonic earphones I could ''visit'' Monument Valley, and with a joy stick I could move my virtual vantage anywhere in the scene and have real-time sound and full-color views. I could watch sunsets from a hundred feet above the ground, or ''sit'' on the desert floor and listen to the wind and animals while watching clouds or the night sky. My computer-generated virtual vantage could even be made to drift with the wind.
I could visit that western scene any time day or night, but mostly I'd use it to watch real-time sunrises and sunsets without having to travel there.
Technology of illustration
The technology of illustration has been developing for at least 20,000 years, always moving toward increased realism. Perspective, for instance, is a development of only about 500 years ago, but photo illustration is the recent development that really puts the hard edge on illustrated reality. Color photography adds even more realism, but the truly big breakthrough has been the recent creation, a hundred years ago, of moving illustrations -- namely movies and television. How would a cave painter have responded to seeing full-color illustrations that actually move?
The technology of illustration is headed ineluctably toward synthetic realities that are indistinguishable from actual realities.
Virtual vantage by means of stereoscopic goggles and stereophonic earphones takes illustration's increasing realism a step further. I was thinking about this when I remembered something I've known a long time but keep forgetting because it's so much a part of minute-to-minute existence: It is a fact of being that if you close your eyes and lie still in a quiet place, it's impossible to assign your consciousness to an actual location in your body.
Does consciousness reside in your head or in the soles of your feet, or maybe eight miles east of wherever your body is, or perhaps permanently in Philadelphia? Truly, no one can say where one's ''center of awareness'' is; it could be anywhere. Though, when we are awake, consciousness seems closely associated with the eyes and with seeing. Our eyes are, both in effect and in reality, video cameras. And our ears are microphones. and the brain is a computer which uses information from the eyes and ears to assemble a synthetic internal representation of external reality.
The person you ''see'' standing right in front of you is in fact part of an internalized image built on the basis of eye-gathered light reflected from the surfaces of the physical world. The people and things we ''see'' are parts of an internal image built from light-borne information which our eyes collect.
And now the holodeck