"It's very hard to describe if you haven't experienced it," Jaron Lanier says. "But there is an experience when you are dreaming of all possibilities being there, that anything can happen, and it is just an open world where your mind is the only limitation . . . All of us suffered a terrible trauma as children that we've forgotten, where we had to accept the fact that we are physical beings and yet in the physical world where we have to do things, we are very limited. The thing that I think is so exciting about virtual reality is that it gives us this freedom again. It gives us this sense of being able to be who we are without limitation, for our imagination to become objective and shared with other people."

Masturbation is one of the earliest forms of Virtual Reality (VR): the mind fools around while the hand fools about. So, in that sense, we're all a dab hand at the oul VR. In fact, all our dreams and imaginings are journeys into virtual worlds, worlds which do not actually exist but which, to us, can seem totally real.

But then what is real? And is there much of a difference, in essence, between what is real and what is virtually real? As far as VR whiz-father Jaron Lanier is concerned, there is no argument. "However real the physical world is," he explains, "the virtual world is exactly as real, and achieves the same status, but at the same time it also has this infinity of possibility."

What is Virtual Reality?

In its modern incarnation, it is a computer generated multimedia environment which simulates, expands and enhances reality, and which allows you to become a participator in the event, rather than merely a viewer or external manipulator of it. Basically, VR creates a computer-generated world, which you can hop into and play around in.

Somebody once said that art is not truth, that it is a lie which helps to illuminate or uncover the truth. But, perhaps even more importantly, art is a means by which we escape from the truth, from what is real. Whether through music, books, pictures, films, video games or VR, we seek a constant escape from the reality prison.

In a truly virtual world, Mount Everest can be climbed from your sitting room; you can run a marathon; you can explore the planets or the depths of the sea. In a truly virtual world, you don't need to physically get up and leave to get there. You can travel in time, with time, beyond time. You can plug in, turn on and take off. And you can fly like the fighter pilots did over Baghdad if you want, and drop your load. And then return to base, to be interviewed. And when you're asked what it was like, you can reply, like one pilot did: "It was exactly like the movies."

The ultimate objective of VR is to create an environment which seems so real that while we are playing or working within it, we believe it to be absolutely real.

Thus VR promises to turn your living room into a galaxy of new worlds. Already we are being bathed in the glows from the entertainment and information pages. We are experiencing the emergence of virtual communities, linked by wires and satellites, rather than streets and townlands. Personal robots who will wash, clean, cook and maybe even have sex with us, are peeking their noses above the horizon. The virtual world is being born all around us.

For the older generations - those born and bred into the 'real' world - it will be difficult, if not impossible, to adjust fully. We grew up seeing the world as some gigantic place, only to watch it diminish through adult eyes. Our computer-literate children are growing up wanting more worlds than the one, wanting more possibilities than we could ever have imagined.

They are speaking lingoes which leave us baffled and outside. Whereas we were happy to watch Star Wars, they want to participate in them.

What do you need to get started?

The first thing you need is a computer, and it is the great reduction in cost and increase in power of computers which has made VR a practical reality for both the mass industrial and consumer markets of the '90s. The computer, through software engineering, creates the virtual environment, sometimes known as cyberspace, virtual space or the virtual world.

Cyberspace could be a room with a desk in it, a galaxy, or the inside of the human brain. Some software designers believe in an open-plan approach to creating cyberspace. In other words, it's a blank canvas until the 'patron' (the person 'playing') enters. Then they can create the world of their imagination using a list of commands.

However, creating your own world requires not just a hell of an imagination, but also the ability to apply that imagination in a technical way. Added to that is the fact that most of us are lazy and prefer to go on a trip, rather than build the road and the scenery along the way. As a result, most cyberspace involves a pre-set environment.

The next thing you need is a 'sensor'. A sensor is something which reads your senses: sight, touch, hearing, smell, etc. Then you need an 'effector'. An effector gives you the sense that you are in cyberspace. Most VR designers would regard the head-mounted display as the basic sensor/effector tool.

As the name implies, a head-mounted display fits on your head. It looks something like a snazzy motorbike helmet. Before your eyes are two TV-like screens which show you cyberspace. Special devices within the helmet track which way the head is positioned. Thus, if you look straight ahead you see what's ahead of you; if you look to the left you see what's to the left of you and so on. This is the beauty of VR; cyberspace surrounds you; you are in its world.

However, the achievement of this other-worldly impression has a cost. Because the screens are close to your eyes, they must be very small. Creating pictures on such small screens which resemble something truly natural and highly-defined, is presently technically difficult and very expensive.

The VR machine that I tested - the British firm, W Industries' SD 1000, at the Atari Family Centre in Tallaght - showed very blocky graphics, which were of a substantially lower quality to the graphics you get on most video games. Until, the VR industry can solve this resolution problem, it is unlikely that VR games will catch the imagination of the very choosy video-game heads.

Headphones are essential. These ensure that as you are bombing through space, knocking out those nasty aliens as you go, you can hear them explode. The more advanced head-sets have a two-way audio system, so that you can give commands as well.

The SD 1000 is controlled by two joysticks, which allowed me to turn any way I wanted and then zap the enemy with super-dooper guns. A much more advanced joystick, and something now only found on the very expensive VR machines, is the 'DataGlove'. This is where VR becomes more than a smart illusion and something that in its full realisation - the data body suit - has the potential to revolutionise human society in a way that beggars the imagination. This is where the trip really takes off, a trip which was predicted by good old Marshall 'Global Village' McLuhan, when in 1965 he talked about, "the final phase of the extensions of man - the technological simulation of consciousness."

Is there any rock 'n' roll angle to all this?

There's lots of them, actually, because many of the Californian children who grew up to create VR were nourished on the rock 'n' roll acid-tripping philosophy of wild colonial boys, Timothy Leary, the Grateful Dead and the like. In the mid-eighties, dreadlocked, free-wheeling musician and computer genius, Jaron Lanier, met Tom Zimmerman. Zimmerman was experimenting on a glove-like device which would allow music fans to play 'air guitar'! By wearing the glove - which was linked up to a synthesiser - the aspiring air guitar hero could create runs by wriggling his fingers in mid-air.

Lanier was suitably stunned and began working with Zimmerman to fully develop the DataGlove. Together they invented a software program which created a cyberspace within which the DataGlove could move about, directed by the hand it was fitted to in the 'outside' world. When Lanier showed this program to his friends, "Their eyes would get wide and their jaws would drop."

Welcome to the virtual world. The DataGlove brings you in. Only the virtual world, as Lanier enthuses, is like no other. "Sometimes I think we have uncovered a new planet, but one we're inventing instead of discovering. We're just starting to sight the shore of one of its continents."

Indeed when VR can get its technology together and its price becomes truly competitive, it's going to have an enormous impact on how we entertain ourselves. The poet Delmore Schwartz once said that, "In dreams begin responsibilities." With VR, in dreams will begin new worlds. Anything imaginable will have the possibility of becoming virtually real.

Battletech is a VR game where you sit into a tank console. Once inside you see a virtual battlefield on your screen. You can manoeuvre around this battlefield, shoot, etc., using steering devices, joy sticks, etc. The enemy is the most dangerous enemy of all, man. Because what makes Battletech so exciting is that the enemy tanks you will be meeting will be driven by other players, other humans.

Ridewerks Turbo Tour Theatre has a screen which is 60% larger than the average film screen. On this giant screen are projected specially commissioned fantasy adventure films, created by people such as those who worked on Star Wars, Star Trek, Poltergeist and Ghostbusters. What makes the Theatre unique is its turbo seats. These seats move with the film, simulating for the viewer, the film's environment.

Imagine running over roads, then hopping on a bicycle and cycling for a couple of miles, then getting into a boat and crossing a lake. Using VR, it is possible to create these environment within a gym or building anywhere. You come in, tog out, get on a treadmill and put on your head set on. Then you're running in the country side or wherever. You get off the treadmill and onto a gym bike. As you cycle up the virtual hill, the pedals get harder to push. Then it's into a gym boat. You grip the oars and you're away, gliding across water.

But what has it got to do with the real 'real' world?

Those who want to be entertained have very high imaginative expectations because they have seen Terminator 2 and the like. Therefore, until VR technology achieves similar visual qualities and effects, it is not likely to explode onto the entertainment market. However, within industry, the visual thrills have a lower priority. What is important for companies is VR's capacity to test out scenarios. VR allows a company to test a simulated product in a virtual environment, to see how it works, and then to modify it if necessary until it achieves the 'perfect' fit.

The Matsushita showroom in Tokyo has a Kitchen World. Potential customers choose their preferred kitchen, with cabinets, appliances, etc., in it. Then they put on a DataGlove and head-mounted display and enter this virtual kitchen. They can walk around it, sit down and test the table for leg room, reach for the cabinets to see if they're too high, open and close drawers, turn on the taps, etc. As they go about this tour, they can have the kitchen modified until they have the kitchen - literally you might say - of their dreams.

A multinational company wants to hold more regular board meetings, but the costs and inconvenience of travel inhibits them. No problem to VR. Each board member, throughout the world, can put on their head-mounted display and DataGlove and walk into a virtual board room and sit down beside a virtual conference table . . . and talk.

Early VR, such as flight simulation, grew out of the need to train people on expensive equipment without putting that equipment at risk. From the medical point of view, VR is ideal, in that student doctors can be trained on a virtual patient.

VR will allow qualified doctors to carry out diagnosis with enhanced information. At the University of North Carolina, they are developing an approach where a doctor using a head-mounted display can see ultrasound images as he or she scans a pregnant woman's uterus. Such an approach allows the doctor to virtually see through the patient.

"The advantage for the doctor is that he can see the three-dimensional position of the baby in the mother's body," Gary Bishop, a research associate professor at the university, explains. "Suppose he wants to stick a needle in there to do a biopsy. He wants to make sure he hits the right place." Bishop goes on to indicate how VR can be of help during brain surgery. "With this system, the surgeon holds the probe, sees the tumour underneath, and knows the angle to go in."

The applications for VR in medicine are immense. Using VR, doctors can create a virtual body, then transfer the medical history of a particular patient into it. Then they can literally walk around inside this virtual body, examining whatever organs need to be examined. An example of this occurred in the San Diego Supercomputer Center, where two doctors walked around inside the brain of a patient, analysing as they went. Another advantage of medical VR is that a surgeon could conceivably carry out an operation on a patient in a remote location, while the surgeon could be thousands of miles away.

While VR may be useful in medicine, the fact that a large percentage of VR games are concerned with killing should be no surprise. VR, as with most other advanced technologies, has been heavily funded by the military. The ENIAC, regarded by many as the first computer, was developed during World War II in order to calculate the trajectories of missiles. World War II also saw the introduction of the first electronic flight simulators, which were used to train fighter pilots.

The US Navy-funded Whirlwind Project helped to lay the foundations for computer simulation and real-time interactive systems. Among the earliest research on head-mounted displays was that carried out at the Wright-Patterson Air Force Base. Such research resulted in the first virtual reality experiments at the NASA Human Factors Research Division.

The Gulf War could be regarded as the first 'virtual' war. Iraq has had its terrain, cities, towns, etc., exhaustively mapped by satellites. All these pictures have been fed into a massive computer system, which has created a virtual map of the country. The American pilots were thus able to carry out their training over this virtual map, learning - in theory at least - the exact positions of all Iraqi triple-A-batteries, surface-to-air sites, etc.

So we can forget about sex and drugs then?

On the contrary. Considering VR's roots in masturbation, it is no surprise that the sex industry sees great promise for 'cybersex' or 'teledildonics', as some have labelled the new area. Already, cybersex software development is under way in America and Germany. Data body suit with appropriate data condoms could make safe sex a highly enjoyable virtuality. However, cybersex is also wide open to more extreme and experimental applications. Certainly cybersex could bring a new meaning to phrases such as "In Bed with Madonna."

"I think this is one of the most important meetings ever held by human beings." These are the (typically modest) words of Sixties alternative life guru, Dr Timothy Leary, the man who invited a generation to "tune in, turn on, drop out." And no, Leary wasn't addressing a meeting of marijuana fiends - the conference was SIGGRAPH (Special Interest Group, Graphics of the American Association of Computing Machinery), held in Dallas in August 1990, and the main theme of the massive and sprawling get-together was, of course, VR.

Leary isn't the only drugs buff to have taken a shine to virtual reality. John Barlow, the Grateful Dead's lyricist, has this to say about VR. "Maybe VR is just another expression of what may be the third oldest human urge, the desire to have visions. Maybe we want to get high." However, Jaron Lanier does not like the idea of equating VR with LSD.

"VR affects the outside world and not the inside world," he argues. "It creates a new objective level of reality. You enter it in a waking state. There is a clear transition."

Is it possible to get hooked (up)?

If you have a computer and a modem, the right software and a telephone line, then you can become part of the network, part of the virtual community. At present there are some twenty million people networking across the world in what can be described as a global virtual community. Obviously, not everyone is linked into the same network. There are countless subdivisions, countless special interest groups. Networking is particularly popular in America, where there are specialised virtual communities such as: alt.life.sucks, alt.sex.wanted, alt.atheism, alt.beer, alt.angst, alt.culture.electric-midget, alt.bite.my.butt and alt. on.

What happens is that you log in to the network of your choice and start typing out what you think. You could be doing it from Dublin, but get a reply from San Francisco or Tokyo. By no means all of these virtual communities are trivial hobbies. Some, such as alt.support.mult-sclerosis, provide advice, support and information.

Howard Rheingold, author and member of WELL (Whole Earth 'Lectronic Link) virtual community, explains how WELL has helped a member whose son was diagnosed with leukaemia. "Within minutes, an information and emotional support task force had been assembled, helping make sense of blood counts and test results. Most important, there were other parents there, 24 hours a day, to share what can't be boiled down into numbers."

VR and networking promises to bring a virtual world into your living room. You will be able to send letters instantly; you can access massive data banks, giving you information about everything from the state of the Chinese economy, to what's the best CD player to buy; you can book a flight; you can bank; you can shop; or you can simply play games.

We're not there yet. But do you remember what personal computers were like in 1979? Compared to today's models, they were crude in the extreme. And as Ben Delaney, editor of CyberEdge Journal explains, "VR is where personal computers were in '79."

If you have a TV, have a good look at it. Because today's TV may soon be an antique piece. New digital designs are on the way, bringing us TVs a few centimetres thick, which will be able to hang from your wall like a painting, and which, because of their use of fibre-optic cabling, will be able to give you 150 channels or more. This TV will be a computer, a VR machine. With your DataGlove or DataSuit, you'll be able to enter into it's virtual world. You'll be able to sit down with friends in a virtual cafe. If you want, you'll be able to go shopping with them too, to buy virtual beans and bread, which will become real when they are delivered to your house.

The world will never be the same again, will it?

In some ways, the future potential of virtual reality is frightening. Will people want to leave their homes at all when their every need can be met from the living room? Will people like Howard Rheingold be so busy helping out members of his virtual community whose children have problems, that he will ignore his own children's need for a father to talk to and spend real time with them? Will we become techno addicts, dependent on technology to get and express ideas, entertainment, love?

Many of those who use the virtual community networks, think the opposite. They believe that VR and networking opens up the lines of communication. They include people such as Bryan Lockwood, who lives in Atqasuk, Alaska (population: 260), reachable only by plane. The network for him is a lifeline to the outside world. Jaron Lanier similarly believes very strongly in the idea of VR as interactive communication.

"Our society has been completely warped by technology, but the technology is still astonishingly primitive. Considering that kids grow up with TV - a one-way medium - there's a tendency towards non-interactivity. After this it will be interactive technology."

Me? I see VR as being another example of human society disassociating itself from its natural environment. I'm not talking about calling a halt to all this progress - that's an impossibility. And anyway, I have a computer and modem myself, and I'm thinking of buying the software to log into the network. However, I can't help but feel that there may be some hidden, fundamental price to be paid for all these new and wonderful virtual worlds.

If we step outside Nature, do we in fact step outside the earth's life cycle? Are we not, in fact, building around ourselves a technological womb? If we begin to belong to a virtual earth, will we begin to lose the ability to deal with and exist within the real earth? Will we come to a point where we have no real connection with Nature - and, by extension, Nature will have no connection with us?

Will we start walking around in DataSuits which do not only plug us in to VR, but also filter out disease and polluted air? And what if someday, somebody or something or some event pulls the plug?

Whatever the future does hold for us, Jaron Lanier is certain that VR will be a big part of it. "This is something," he states, "and we haven't had a something for a while."