PROLOGUE
Imagine being told by a physics teacher that when you throw a cricket ball the trajectory is straight for a given distance followed by an abrupt fall to the ground. You would contest this immediately on the basis of your earliest of childhood recollections that the trajectory is actually an arc. Unfortunately, much of our education is not based on practical experience, but on mathematical abstraction, which often takes some believing and understanding. Perhaps the micro-world of Quantum Mechanics represents one of the most difficult areas, and least understood. In fact, we can safely assume that no one understands Quantum Mechanics! The notion that an atom should change size on the basis of the speed of approach of a proton is something we never experience in our world. Yet this is well founded experimentally and lies at the very core of nuclear fission.

ABSTRACT
The basis of all human understanding is fundamentally linked to our sensory abilities (dominated by visualisation) followed by conceptualisation and then true (and sometimes transitory) understanding. The difficulty is that we face a world where visualisation is becoming increasingly difficult. Interestingly, in 1945, Richard Feynman was working on the Manhattan Project and stated that; "The single biggest problem we face is that of visualisation." This is still true today and can increasingly be seen as a prime limitation to our further progress in a range of technologies. In this presentation, we examine the popular view of virtual reality and consider novel applications relating to the engineering of complex non-linear systems in the information world. Our basic hypothesis is that if we could see, touch and feel the objects generated by, and for, information systems and the new abstractions we have to deal with, then our understanding might increase to the point where satisfactory models could be produced.

THE NATURE OF THE UNIVERSE
Throughout our formal education we are fed a diet of problems that can be solved. From our earliest days at school through to degree level, we are fed information and problems that lead us to believe that the universe appears as Fig 1. Here we see a largely solvable mass of problems and things we can analyse and understand with a very small area of uncertainty and lack of knowledge. In later life, we find that this is not the case; we see the universe is not generally linear, simple and easily explained. More, the situation appears as shown in Fig 2. The reality is that the universe is grossly non-linear and so far we have had the fortunate experience of being able to develop the majority of our technologies in largely linear areas. Perhaps the most common example of the development of non linear systems is software. Our experience prior to the arrival of computers is depicted in Fig 3 where we see a very strong linkage between our physical world experience, physical models and mathematics. The arrival of software however, introduces a realm that is wholly artificial and is not linked to any physical entity or world that we have previously experienced. We therefore see a new universe, with an abstraction beyond that of mathematics and one that is extremely difficult to understand. The sheer scale of software running to millions of lines of code, with tens of thousands of feed back loops and decision points, is something way beyond human ability to understand - so far!

An analogous situation to that of writing software, and understanding a hugely complex system, is that of trying to build a bridge on the basis of the binding energies in the atomic nucleus of the iron atom instead of using Young's Modulus. Young's Modulus is an abstraction that allows us to stand back from the deep physical understanding of the material with sufficient accuracy to allow the construction of an entity that is fit for purpose. The difficulty with software is that at present we don't have such a level, or suitable form, of abstraction. So far we have migrated from (abstracted) machine code to high level languages, and often in a graphical form, but we still do not have a total systems nomenclature that allows us to grasp the overall picture. Perhaps Virtual Reality would allow us to enter this realm and get a new view, and hence a better understanding of non-linear systems and software.

A MIND EXPERIMENT IN VR
Suppose you were a grain of salt inside a pot. What would your experience be? If the salt pot is tipped upside down you would experience a change in orientation in a largely stable world. Gradually you would feel and see slippage and movement around you with a sudden acceleration, falling sensation, abrupt deceleration and stability. Some time later, you would be involved in a series of land slides and earthquakes that would come and go, ultimately giving way to total stability. It would be extremely difficult for you to imagine the form of your universe. However, if you were lifted out with a pair of tweezers and placed at a distance so you could see the pile of salt, then you would have an instant understanding of the system that governs your world. In essence, this is how Virtual Reality can aid our basic understanding, by allowing us to observe from a new vantage point. That vantage point can be as abstract a place as an electron, a proton, red dwarf, or a point in a data set, electromagnetic field or as mundane as a designer kitchen, architectural drawing, or inside the human body or car.

REAL EXPERIMENTS
Let us take two extreme examples as shown in Figs 4 and 5. A large percentage of the population have difficulty with 3-D visualisation from 2-D drawings. The designer kitchen shown in Fig 4, is one example of how this technology can help people to realise what they are about to purchase, or what they have just designed. Perhaps more challenging would be the ability to reach out and feel an electron that is a rather uncertain jelly like entity easily removed from the outer fringes of the atom. Whilst in contrast, the neutron is hard and round and solidly locked into the nucleus to the point where we have extreme difficulty removing it. Perhaps we could even see and feel how molecules latch together as we construct a new form of drug (Fig 5). How much better to learn about atomic physics from this standpoint, than from a series of abstract numbers that are so small and large that we have difficulty comprehending. Our real world experience of gravitational force is difficult to relate to the binding energy in the nucleus, which is ~10 39 times greater. Such numbers tend to be meaningless, even to the well trained and educated.

DATA WORLDS
A growing difficulty of modern life is the explosion in the amount of information available and the format in which it is presented. It is not uncommon for today's executives to receive a 3cm thick report only hours before a meeting, where they are expected to have done all the necessary reading and be in a position to make an educated set of decisions. This is fundamentally impossible and an irrational expectation. An alternative approach is to put information into a humanised form that recognises our inherent ability for visual correlation and pattern recognition. Two examples are shown in Figs 6 and 7, where data fields of enormous complexity can be rapidly assimilated .

There is a progressively greater human ability moving from black and white 2D through to colour 3D with animation. Experiments with senior managers have confirmed our innate capabilities to digest and understand up to 2 Gbits of information in less than half a minute. This same information set in paper form would represent several volumes of the Encyclopaedia Britannica as raw numbers and several inches of paper in terms of 2D graphs. Our innate ability to visually correlate, and recognise patterns, can be enhanced further by allowing observers and participants to move about inside the data field to view the information from new and very different perspectives. The remaining challenge is one of defining a reasonably common set of formats for regular data encounters, whilst finding a low cost solution to the visualisation of raw data sets.

FULL INTERACTION
Today we use the telephone to extend our ears and mouths over vast distances. The same is true for visual communication, with the television screen and camera extending the reach of the eye. Extending our sense of touch is also feasible, as the time for information to travel from our fingertips to our brain (~10 ms) is of the same order as the time taken for a single photon to travel from the UK to the USA (~ 30 ms) on an optical fibre. Given that this time delay is dominated by synaptic processing (~30 ms), and our innate ability to accommodate delays of 100ms or more (e.g. riding a bicycle), then an extended hand across the Atlantic is feasible. The ?feelie gloves? and ?prosthetic arms? currently being developed (Fig 8) will allow the VR participant to reach out, and not only grab, but feel and then react to the tensions and forces, the tactile qualities, size and viscosity of entities. This is also true of information. Early experiments with graphical data and emotional icons (Fig 9) in this context have revealed a number of interesting advantages when linked toArtificialIntelligence (AI). Reaching out for information that reacts in a humanised way as being friendly or aggressive, defensive or nervous, allows participants to be steered through a decision making process with realistic cues abstracted from real life. This is in complete contrast to most interfaces that have been engineered for the convenience of the technology rather than the human.

SPLIT SENSES
In many walks of life human beings operate with sensors diversely focused on a number of activities. Perhaps the most common example is that of the pilot who will talk to ground control with the use of one ear whilst listening to his co-pilot in the other. At the same time he may be viewing activity on the runway and controlling the aircraft with his hands. A recent realisation has been that the split ear operation can be extended to the eye. It is possible for human beings to work in two visual worlds at once, the real, and the virtual .

A commercial manifestation of such a system has been named CamNet, where the operator utilises a conventional audio headset augmented with head mounted TV camera and television screen (see Fig 10). It is therefore possible for expertise to be teleported from one part of the world to another. Specifically, this can be used for the maintenance of complex equipment, surgery, medical examinations, remote visits to new locations, loss adjusters for car repairs and many others. The principle is quite simple. By projecting the view from someone's head back to a site many thousands of miles away, it is possible to perceive the world of another human being. Instructions, schematics, fixed and moving images can then be transmitted back to the wearer, who can receive the latest information about the equipment or problem he is working on. The addition of tactile and prosthetic transmission, plus remote instrumentation, then creates the ultimate teleportation of human abilities. Expertise on demand, anywhere, any time!

An obvious extension is to place two cameras at eye level on the wearer and at some distance provide a virtual reality headset. It is then possible for thousands of people to sit behind the eyes of the wearer of the cameras and enjoy a full binocular (3D) view. This surrogate head could have interesting and important applications for the instruction surgeons, students and sports or ceremonial presentations. One person is able to gather all of the scene and relay it back to remote locations without any sophisticated guidance or control system.

BEING SOMEWHERE ELSE
Ultimately we might envisage that millions of people could be teleported to a single seat in Yankee stadium or the Wembley arena. A single optical unit (rotating camera) placed in one seat could gather all the optical information and teleport it to thousands of locations. At these independent locations the wearer of a VR headset would be able to move and look to front, back and side and see all of the scene around that seated equipment. In the future we might be able to experience the full panoply of the Olympic Games, without leaving our living rooms (Fig 11).

The head-up display of the pilot is now a well established technology and one that we might envisage migrating into the VR world. We have already mentioned the ability of the human being to work ?split ear', but we also have the ability to work ?split image'. That is, we can view the real world, or a virtual world, whilst also having graphical and other information in between the far field and our pupil (Fig 12). Such technology allows us to be in many places, and multiple roles, all at once.

THE INFORMATION WAR
In the main we can see the general direction of hardware developments for the next 10 to 30 years. Since 1960 we have seen the electronic packing density double in micro-electronics. Similarly, our ability to transport information in telecommunications continues to double each year. This means that we can expect the computer on the desk to be 10 3 times more powerful in 10 years from now, 10 6 times more powerful in 20 years, and probably 10 9 times in 30 years. Clock rates, and hence information rates, will also migrate from Mbit/s to Gbit/s. Storage, processing and telecommunication costs can be expected to continue their exponential decline - effectively becoming free! To this extent we can consider the hardware war to be over (for the present). The next phase is likely to see a migration from electronics to photonics, and from digital back to analogue. Software is also on a reasonably well defined trajectory. New developments may see some real understanding and engineering arrive within the decade with; artificial life, intelligence, genetic algorithms and evolutionary principles creating a new era for software. Again, to this extent, the software war will soon be over, and it is already well advanced. Software can thus be expected to go the same way as hardware, it will effectively become free, and will be written, configured and shared by everyone.

The next technology wave will be information - or content. This war is just about to commence. In the near future, if not now, it will be imperative that we are able to access information anywhere, at any time and in any form. Information is all around us, it is abundant, it is diverse and rich. For example: there are 6 x 10 6 pictures of church widows alone; new books are published at the rate of 35 km of book shelving per year; 500 television channels will soon be available in the USA; and video on demand could offer an instant choice from 8 x 10 3 programmes. How are we going to interface with such systems and stand any chance of being able to find and zero-in on our choice in a reasonable amount of time ?Now one knows !

VR OR MULTI-MEDIA?
The principal choices we have for the human interface at present are between multi-media and VR. Looking at the potential complexity of the information world we are now building

it will be an interesting contest. Multi-media is generally constrained to the standard search tree approach, whilst VR offers the potential of immersion and the random walk through. Coupled with AI techniques this becomes a formidable approach that would be intuitive, natural, and make the technology available to the vast proportion of the population.

It is interesting to reflect that the forms of information we now enjoy were dictated by the means of storage and transmission devised before biblical times. We have therefore become locked into a narrow range of realisation dictated by our past history and limited human senses. VR offers the prospect of entirely new forms of information and interaction. Because of the density of our visual cortex, and it's dominance as a means of entry to the brain, we might anticipate that vision will play a dominant role. Coupled with the developments in super computing, perhaps we are about to witness the creation of the mind amplifier! The augmentation of our natural analogue (intuitive and heuristic) skills with the precision, speed and certainty of a digital (logical but unthinking) counterpart.

FINAL REMARKS
Virtual Reality has received a considerable amount of media attention, and probably for the wrong reasons. It is just another technology in a long line of developments that involve the extension of the human sensory system, that is naturally contained within the body, to new domains through electronic means. The telephone is established and so is our ability to teleconference the vision of communications. Extending the tactile, the prosthetic and who knows, even more of the sensors such as taste and smell, we will then be able to transport the whole human sensory system to a new domain. Potential applications cited here are but a glimpse of what might ultimately be possible. Beyond the media hype the potential is great and the applications infinite.