Virtual Reality: Directions of Growth

Notes from the SIGGRAPH '90 Panel

by William Bricken

9/10/90
I.    INTRODUCTION

Virtual reality (VR) systems were introduced to the general public by  
VPL and by Autodesk on June 6, 1989, VR Day, at two trade shows.   
This event was preceded by about four months of media coverage.   
Since then, VR has captured the public's imagination.  It is also in  
the unique position of being commercially available before being  
academically understood.

Any technology which has the audacity to call itself a variety of  
reality must also propose a paradigm shift.  In essence, a paradigm  
shift expands the potential of an entire discipline.  For me, VR has  
expanded every aspect of Computer Science, and is providing a base  
for a very satisfying philosophy as well.

And just what is the paradigm shift?  Computers are not only symbol  
processors, they are reality generators.  Until recently, computers  
have generated only one dimensional symbolic strings.  Text and  
numbers.  Text is a code which, when read, generates images of  
reality in our minds.  During the 80s, we enhanced the expressability  
of computation by adding space and time dimensions to the realities  
being generated.  Two dimensional windows, 2D animation, solid  
modeling, simulation.  Now, in the 1990s, computer systems can  
generate virtual environments, entire multisensory worlds which  
include us as interactive participants.  Digital information can seem  
as-if-real, changing our notions of computation, symbolism, meaning,  
metaphysics, self, and culture.  Virtual realities are more than  
real.

The potential for VR to contribute to societal infrastructures such  
as manufacturing, marketing, telecommunications, science,  
entertainment, art, education, medicine, and media, suggests an  
economic impact that rivals the Gross National Product.  We live in  
two superimposed worlds, the one of mass and the one of information.    
The huge accumulation of difficult to access words on paper indicates  
that the world of mass is not particularly well-suited for dealing  
with information.  As our culture matures into an information  
society, we are now discovering the virtual world, an ideal place for  
interacting with information.

What follows is a wide ranging discussion of interesting growth areas  
for VR.  I'll define VR, point to some active areas of research, tell  
you about virtual world tools, outline some things we have learned  
from working in the field, and discuss some risks and philosophies  
engendered by VR techniques.


II.  THE RESEARCH SUITE

VR is the body of techniques that apply computation to the generation  
of experientially valid realities.  HITL is forming its research  
agenda around a suite of three interrelated technologies:

	Behavior Transducers
		hardware interface devices
	Inclusive Computation
		software interaction techniques
	Intentional Psychology
		biological constraints and plasticity

Behavior transducers map natural behavior onto digital streams.   
Natural behavior is what two year olds do:  point, grab, issue single  
word commands, look around, toddle around.  Behavior transducing  
interface devices include body trackers, voice recognizers, spatial  
sensors, kinesthetic feedback devices, and subjective audio and video  
displays.  Transducers work in both directions, physical behavior to  
digital information (the virtual body) and virtual display to  
subjective experience (the physiological model). 


Inclusive software provides tools for construction of, management of,  
and interaction with digital environments which surround a  
participant/user.  The central design issue for VR is getting  
behavior transducers and virtual environments to feel good to a  
participant.  The intentional psychology of VR will require a deep  
knowledge of how we work, our physiology, our sensations, our  
cognition.  We must refocus the effort of interface from the needs of  
symbol processors to the needs of people.


III.  THE ESSENCE IS INCLUSION

We at HITL believe that the primary defining characteristic of VR is  
inclusion, being surrounded by an environment.  VR places the  
participant inside information.  Some of the changes in perspective:

	picture  -->  place
	observe  -->  experience
	use  -->  participate
	interface  -->  inhabit

When we extend our field of view onto a computational environment  
beyond about 60 degrees, a remarkable phenomenon occurs.  We shift  
from a feeling of viewing a picture to a feeling of being in a place.   
This shift is accompanied by an emotional response.  It seems as  
though the unification of our symbolic processes with our visual  
processes creates a feeling of wholeness, of empowerment.  We shift  
from external users (exercising rights) to internal participants  
(exercising responsibilities), from being observers to having   
experiences, from interfacing with a display to inhabiting an  
environment.   


My colleague Meredith Bricken and I have collected videotaped  
behavior and exit interviews from over 500 people that we have guided  
through initial VR experiences.   We have seen overwhelmingly  
positive responses, eagerness to return to "that place", willing  
suspension of disbelief.


IV.  VIRTUAL WORLD PROJECTS AT HITL

Our knowledge about VR and about how people respond to the VR  
experience is being extended at HITL through several active projects:

	information database, sci.virtual-worlds
	simulation laboratory
	virtual environment operating shell
	laser microscanner display techniques
	design and construction of worlds
	3D audio display
	instrument display prototypes
	multiple participant worlds
	educational experiences and environments
	virtual prostheses

The information database is a project for NASA to follow the  
development of VR and to serve as a clearinghouse for references and  
research in the field.   Sci.virtual-worlds is a moderated USENET  
newsgroup for the discussion of VR issues.

The simulation laboratory  provides a research environment for  
prototyping VR hardware and for testing and evaluating effects on  
human sensory, perceptual and psychomotor behavior.  


The Virtual Environment Operating Shell is a software suite currently  
written in C that wraps around the UNIX operating system.  VEOS  
provides resource and communication management for coordination of  
the modules which make a VR system:

	i/o hardware, behavior transducing input and display devices
	world construction kits, CAD packages
	dynamic simulation kits, for interaction and animation
	virtual world tools
	computational and display processors

The laser microscanner is a hardware research project to design a  
high performance, low cost virtual display.  Rather than creating an  
aerial image using cathode-ray tubes or matrix element devices, the  
laser microscanner scans a color image directly onto the retina.  We  
don't think in terms of addressing pixels, we think in terms of  
addressing rods and cones directly.  The head-mounted unit will  
integrate 3D visual and audio display, voice recognition, and head  
and eye tracking.    


We build worlds for presentation, evaluation, and experimentation.   
Our interest is the design of comfortable, functional worlds.

For Boeing, we are exploring 3D audio display techniques, and  
building prototypes for design and display of complex instrument  
panels and machines, in essence simulating the design of aircraft  
cockpits.

We are working on the implementation of multiple participant worlds  
for an application to telecommunications.  You can think of VR as a  
very sophisticated replacement for the telephone.

Education and industrial training are natural applications of VR  
techniques.  We are designing virtual environments conducive to  
learning, we're studying the transfer of skills between virtual and  
actual tasks, and we're exploring the implications of VR for  
educational theory and practice.

And we have great interest in the application of VR to prostheses for  
the handicapped, for providing virtual bodies which extend individual  
capacities,  for providing alternative control devices for  
interaction in virtual worlds.


V.  OTHER RESEARCH AREAS

VR has intersected other areas of research in some surprising ways:

	audio modeling
	teleoperation, telepresence
	image integration, HDTV
	interactive drama
	military simulation

3D audio hardware is commercially available, we should expect to hear  
of inclusive sound systems in the stores soon.  Audio theorists are  
interested in specification languages for 3D music, in audio lenses  
and icons (earcons), and in modeling ambience, the analog of  
ray-tracing for sound.

Telepresence, the development of remotely controlled robots, requires  
the same interface techniques as VR.  The primary difference between  
these disciplines is that teleoperation looks at interaction with  
real (usually  inaccessable) images, VR looks at virtual  images.   
Both want inclusive, interactive environments.  The possibility of  
inhabiting real worlds shook me out of a self-imposed computer  
graphics narrowness.  We can apply VR interaction and hardware  
techniques to explore anywhere we can place a probe.  We can inhabit  
a remote undersea vehicle, processing digitized images into worlds  
that mix the actual with the virtual.  We can swallow a miniaturized  
transmitter and explore our own stomach.  We can build artificial  
bees with fiber optic visual links and micromotors for dancing and  
for rubbing antennae.  We can then put our virtual bee-selves into  
the physical hive and interact with real bees in their home  
environment.  I can hardly wait.

The multimedia community is very interested in digital images.  It  
seems only natural that we should port these flatlander tools into  
VR.  We could tile polygons with TV.  More importantly, automated  
conversion of images to 3D objects (the image recognition problem)  
would permit a seamless integration of video-real with  
graphic-virtual.

Hypertext has raised the question of interactive fiction.  The  
theatrical community is working to install plot and character into  
virtual worlds, creating interactive drama.  What do a good story and  
a good experience have in common?  Can we construct participatory  
plots, guided experiences, autonomous characters?

Actually, VR grew up in the military.  The first substantive  
application of VR was to help Air Force pilots improve their ability  
to aim missiles.  The most refined and widely distributed VR  
environment today is SIMNET, a large scale, simulated tank combat  
system.  Recently, I saw a paper on training close combat fighters in  
VR.   Sort of reminds me of the video arcade.  



VI.  VIRTUAL WORLD TOOLS

To give you an idea of what work and play will be like in VR, I'll  
describe some of the tools we're designing at HITL:

	the wand
	the virtual body
	virtual home, virtual community
	concurrent inconsistent worlds
	autonomous entities
	concrete mathematics, experiential programming

The Wand is an evolution of the Mouse.  It is a simple physical  
device with a wide diversity of uses, ideal characteristics for a  
tool.  Physically, the wand is a spatial position and orientation  
sensor on a handheld stick.  In software, the Wand emanates a ray  
which can be used for pointing at virtual objects.  Coupled with  
voice commands, the Wand can be used to identify objects,  to attach  
to and move objects, to bring things closer or place them at a  
distance, to indicate a direction for flying, to identify a location  
to teleport to, to measure distance, as a pen for drawing, as a  
knife, as a switch, as a spotlight.  Lots of functionality from a  
little hardware.

People achieve presence in VR by inhabiting a virtual body.  The  
virtual body is a software toolkit for associating an arbitrary suite  
of behavior transducers (such as wands, voice command systems,  
headtracking, etc.) to a display of self in a virtual world.  What we  
do physically is sensed and converted to virtual behavior.  Don't  
think that the virtual body is necessarily in the shape of our  
physical body;  any object in VR can be inhabited.  If you are  
controlling a physical robot, you may prefer your virtual body to be  
the shape of that robot.  If you are navigating a data terrain, you  
may prefer to have a virtual body shaped like a jeep or an airplane.   
The virtual body can filter and map physical behavior onto superhuman  
capacities.  One of the first things we did to figure out how a  
virtual body might be used was to search the old comic books for  
super powers.

The virtual home is an environment designed for personalized comfort,  
for work and for play.  My virtual home will have a cozy chair, a  
fireplace, some cats, and a cabinet full of virtual tools and toys,  
essentially what I now have at (physical) home.  Physical reality is  
a great starting model for virtual reality.  Take what we like and  
delete what we don't.  


Virtual homes will be customized, personalized environments.  The  
virtual home extends to a virtual community.  People we work with are  
not organized by some cryptic email address that is basically a  
program to tell the network where to find them.  They are organized  
in close proximity in space.  In a virtual community, friends have  
virtual homes that are visible from our own virtual home.  They are  
our neighbors.  We visit them by pointing to their home and saying  
"jack me there".  Less frequent acquaintances may be down the road or  
over the hill.  The idea is to organize virtual space to accommodate  
to human culture.

One profound capability in VR is to maintain inconsistent views for  
different participants, to intermix personal realities.  In physical  
reality, mass has a way of being unarguable.  We quickly default to  
assuming a consistent, objective reality that is communal to  
everyone.  Consistency is an assumption and is widely  
overgeneralized.  Each person in physical reality, for example, has a  
viewpoint, each viewpoint is necessarily in a different physical  
place, each perspective provides different information about the  
inclusive  environment.   Every experience is unique.  We agree to  
suppress our differences for massive objects, but the line is always  
fuzzy.  We certainly tolerate differences within the domain of  
conversation.  How we talk is an excellent example of concurrent  
inconsistent worlds.  


In VR, communality can be negotiated rather than assumed.  In VR,   
the color of my shirt can appear to be green to me, but blue to you.   
So long as we do not talk about or interact with the color of the  
shirt, how it is rendered to each of us is irrelevant.  Carry this a  
bit further:  I can be sitting in my virtual home next to an empty  
chair.  You jack a duplicate of your virtual body into that chair.   
From my perspective, you are visiting me.  Now, from your  
perspective, you are still sitting in your virtual home, in your  
customized environment.  You have an empty chair, and I jack a  
duplicate of my virtual body into it.  We are now sitting in two  
totally different environments while sharing a mutual conversation.   
For me, you are in my home, for you, I am in your home.  So long as  
the inconsistencies in our environments are not items of contention  
or confusion, the differences will not interfer with communication.   
When they do interfer, the explicit differences become subject to  
negotiated resolution.

But the pluralism of VR is much deeper.  It is possible to maintain  
inconsistencies directly, without resolution, using a mathematical  
technique called the imaginary boolean value.  We could choose to  
represent the color of my shirt as ambiguous, as context dependent.   
Both green and blue.  We can then discuss the color of the shirt as  
being inconsistent, as information about which we simply do not see  
eye to eye.  I bring up these ideas from an esoteric branch of  
representation theory to illustrate a fundamental point.  VR is not  
bounded by the assumptions of physical reality.  We can have whatever  
we can formally specify.

The HITL architecture specifies that every object in VR, including  
space itself, have processing and memory resources.  Entities are  
objects with the capabilities of operating systems.  Every entity is  
a system, every entity is a variant of the same system.  This means  
that we can use the same editing, debugging, and interaction tools  
for modifying each entity.  Entities are running a sense-process-act  
loop;  in artificial intelligence terms, each entity is an agent, an  
actor.  This means that VR is inhabited with artificial life.  Every  
entity is capable of independent action,  in response to  
environmental changes, in response to internal memory or process  
changes, or in response to changes in the rules, the disposition,  
specifying that entity's internal processes.  Each entity is an  
expert system using pattern-matching on its input to trigger  
disposition rules and metarules which generate outputs to the  
context.  The environment itself is just another entity, one that  
includes other entities within it.   All cyberspace is Toontown.

We have been able to demonstrate that mathematics itself (in  
particular logic, integers, and sets) can be expressed concretely,  
using 3D arrangements of physical things, such as blocks on a table,  
doors open or shut, rockwalls that respond to gravity, the things of  
everyday life.  String-based symbolic representations of mathematical  
concepts are typographically convenient, but tokens are not at all  
essential to mathematical expression.  VR makes it convenient to  
express abstract ideas using spatial configurations of familiar  
objects.  One benefit of this approach is that we can build visual  
programs, set them on a virtual table, and watch them work.  We can  
experience programs as other entities rather than as dumps of text.    
Bugs would manifest as structural anomalies, as visual  
irregularities.   Architectural design has a sensual, experiential  
semantics.  It is but a quirk of typography that we have ignored the  
experiential semantics of computational languages.  More  
fundamentally, experiential computing unites our spatial and our  
symbolic cognitive skills, permitting mathematical visualization,  
analytic gestalt, whole brain processing.


VII.  EDUCATIONAL APPROACHES

VR provides an exciting educational medium for exploring worlds and  
for exploring ourselves.  It provides a training environment that is  
rich, replicable, and responsive.  It permits direct evaluation of  
educational theory.  The central educational issue for VR is one of  
transfer of experience.  Do skills and habits learned in VR transfer  
to the physical world?   Here are some educational issues:

	Constructivism
		"Human knowledge is essentially active."  Piaget
	Natural Semantics
		non-symbolic, preoperational interaction
	Programmable Participation
		conducive and responsive environments
	Cognitive Presence
		modifiable self-concepts, learning by becoming
	Social Reality
		unique concurrent worlds

Educational psychologists have long known that people actively  
construct their experience of reality.  In VR, students will  
construct their knowledge, then dwell within it, exploring their  
understanding. 


Natural semantics means that the computational environment hides  
symbolism in favor of displaying information in an innately  
recognizable form.  The two-year-old criterion:  if a kid recognizes  
it, its natural.  The three Rs, all symbolic, will become the three  
ACTs:  enact, interact, and abstract.

VR provides the potential for completely customized, individualized  
learning.  Educational environments will uniquely respond to the  
participant-learner, in terms of both needs and preferences.  A  
student model will not be necessary, instead the teacher and student  
will modify the environment in support of student behavior.

We also have a tool for affective education, for sharing  
perspectives, for mapping perspectives into broader contexts, for  
changing self-image, for remapping capabilities.

Education is inherently social.  Explicitly shared worlds and  
multiple concurrent agreements provide the opportunity for groupwork,  
social consensus, and the construction of functional,  
multiparticipant environments.

In general, everything we do to educate with words and pictures can  
be provided as virtual experience.


VIII.  LESSONS LEARNED

Tom Furness, the Director of HITL, has over twenty years experience  
in VR.  He pioneered most of the hardware interface devices we use  
today, in the extremely demanding environment of military aircraft.   
Personally, I have worked on VR related projects for six years,  
beginning at Atari Research Labs in 1984.  Meredith Bricken designed  
Autodesk's worlds, built Virtual Seattle for CHI'90, and has  
pioneered research into the design of comfortable virtual  
environments.  Over the years we have learned some lessons:

	Psychology is the Physics of VR.
	Our body is our interface.
	Knowledge is in experience.
	Data is in the environment.
	Scale and time are explorable dimensions.
	One experience is worth a trillion bits.
	Realism is not necessary.

A major theme of VR research is that Psychology, in the broad sense  
of behavior, perception, cognition and intention, provides the rules  
and the constraints of virtual worlds.  Psychology is the Physics of  
VR.

This may come as a shock, it is one of those truths that is obvious  
after it is said, but elusive before it is stated explicitly.  Our  
body is our interface.  Interface is not something that is out there,  
in some machine.  Interface is a boundary which both connects and  
separates, interface takes place at the surface of our skin.  From  
the perspective of VR, interface is physiology, interaction is  
natural behavior.  We simply want to use the power of computers to  
make computation invisible.

Knowledge is in experience, it is not in some abstract, symbolic  
representation.  Data is in the environment, it is not stored away in  
some memory array.  These observations serve to remind us that we are  
not the computer.   To understand computation, we should participate  
within it, rather than writing programs to dominate it.  Humans have  
a great skill for projecting outward, for becoming the tool we are  
handling.   We need reminding that we are creatures who dwell inside  
an environment.

VR is inherently multidimensional.  As well as freedom of translation  
and rotation, in VR we can travel in scale and in time.  Think of  
scale as simply another direction;  when we traverse scale, size  
instead of location changes.  We can also travel through time using  
any of the techniques of film editing, including slow-motion, fast  
forward, and temporal discontinuity.

There is a tremendous compression ratio between digital information  
and human experience.  Very approximately, it takes a hundred million  
polygons to simulate what we see in one scene.  Add duration,  
multisensory channels, and interaction, and you get a lot of digital  
information being transacted with each moment of consciousness.   
Computation will not come close to this bandwidth for a long time.   
Fortunately, virtual world experience does not require the  
information density of physical reality.

Because our minds provide such tremendous flexibility in interpreting  
what is outside of us, realism in VR is simply not necessary.  Our  
cognitive plasticity permits even simple cartoon worlds of 500  
polygons to be experientially satisfying.  We must design worlds that  
respect our physiological needs.  For example, we conceptualize  
perspective in physical space as having six degrees of freedom, three  
in translation and three in rotation.  But our bodies have roughly  
four and one-twelth degrees of freedom.  We move easily in all  
directions on a plane, forward and to the side, but not up, off the  
surface we stand on.  We rotate freely around the vertical by  
turning, but our natural rotation forward, around our waist  by  
leaning, is at best 270 degrees (3/4 of a full 360 degree rotation).   
And our ability to bend side to side is only about 120 degrees,  
one-third of a full rotation.  This adds up to a little more than  
four degrees of physiological freedom.  Input devices which permit  
complete freedom of translation and rotation usually get people lost  
in space.  The dimensionality of our abstract perspective does not  
match that of our physical construction.  We must also differentiate  
that which is innate from that which is learned.  Pilots, for  
example, have learned to fly in all six degrees of freedom.  Realism  
is both physiological necessity and cognitive interpretation.  In VR,  
world design that conforms to physiological necessity frees our minds  
to furnish the rest of our reality.


IX.  COMING ATTRACTIONS

Here are the coming attractions, what I believe will be available by  
the end of the decade:

	public domain VR software
	massive database access
	fabric of space
	negotiable group space
	conversational programming
	artificial life
	crossvalidation of realities

HITL is electing to distribute its software in the public domain.  We  
hope to create a context for the growth of an industry and for the  
understanding of alternative realities.  We hope to encourage the  
evolution of a shared software and hardware environment which will  
permit researchers to share progress and results.  The commercial  
marketplace can then improve on public work, selling value-added  
features like customer support, prebuilt worlds, faster hardware,  
better algorithms, realer time.

VR requires a new approach to database management.  We want to access  
massive databases such as Landsat as a function of our perspective,  
our location in the database.  We expect to see interactive databases  
which we can explore through movement.  Already waiting is the entire  
Earth to one meter resolution, the location of every aircraft and  
ship, large hunks of the Moon, the human body down to the resolution  
of a cell, the flow of the economy, the network of computation.  We  
have digital worlds to explore.

I have mentioned that space is an entity.  Many interactions between  
entities can be expressed as internal processes of the spaces which  
include them.  Gravity is a primary example;  we can implement  
simplistic local gravity by decrementing the Z component of the  
velocity vector of each entity in a space at each time tick. Rules  
that apply uniformly to every entity in a space instead can be  
ascribed once to the space itself.  The inclusive space enacts local  
gravity by owning the locations of the entities it includes.  We want  
to be able to place fields in space, to have space maintain its local  
version of continuity, gradient, and metric, to build space-filling  
logics which branch as a function of location.

One advantage of customized environments is that we will have to be  
explicit about what is shared.  VR suggests an approach to  
cooperative work in a computational environment:  rather than assume  
communality and specify differences, assume complete difference and  
specify what is common.  It may turn out to be fun to build communal,  
consensual contexts, to negotiate the group space.

One consequence of autonomous entities is that they can respond to  
our communications.  With voice recognition, we will be able to speak  
to virtual entities as a means of programming their structure and  
behavior.  "I want the green cube I'm looking at to double in size."   
The cube has a sensor for voice.  Its rulebased disposition matches  
the vocal input to its own identity and to its size changing  
function.  If you have permission, it changes itself to your  
specification.

Another consequence of autonomous entities is that they may have  
their own agenda.  The coupling of the behaviors of several entities  
could determine events.  Rulebases that support emergent behavior are  
tremendously difficult to construct.  We hope that the programmable  
environment of VR will provide autonomous entities with a context for  
the growth of interesting virtual life.

Fundamentally, VR forms a new reality, at least to the extent that we  
are willing to relax our minds.  We will need to calibrate the  
effects of transfer across worlds and across realities.  VR is the  
first empirical tool of metaphysics, it permits us to compare  
realities, to ask which alternative reality is preferable for which  
tasks.


X.  RISKS

Do virtual worlds pose significant risks?  I have prepared a list of  
what I believe are the issues and problems for VR:

	descriptive confusion
	lack of experience
	cognitive remodeling
	fluid self
	sensory overload, sensory ecstasy
	power and control
	cultural adaptability

VR is seeking definition, it could be anything from email to a fully  
surrounding, multi-sensory environment.  We are struggling with  
appropriate comparisons.  VR is not a drug and is not physically  
addictive.  Drugs change our perspective from inside the body, VR  
changes our external environment.  VR may well be psychologically  
addictive (that is, entertaining), just like all good media  
experiences can be.  And there is that constant tension between  
physical responsibility and cognitive exploration.  Is VR escapist?   
Escapism means seeking diversion from physical reality.  VR cannot  
escape being escapism, VR is perfect escapism.  Is VR theater, or  
interactive drama, or is it more than art?    Is it scientific  
visualization, or physical simulation, or is it more than science?   
Is it financial modeling, or the perfect sales tool, or is it more  
than economics?  It's a good idea to spend some time figuring out  
what VR is.

To me, the greatest problem is that we have virtually no experience  
in VR.  There are perhaps around ten thousand VR non-virgins.  But I  
estimate that there are no more than fifty people who have spent  
twenty hours in VR.  All of this excitement is purely conceptually,  
we have very little experience with what we are talking about.  The  
first item on the VR agenda must be to construct and distribute  
hundreds of systems, so that many people can contribute to our  
understanding.  We should know at least something about the cognitive  
effects of VR before it is a consumer item with the distribution of  
Nintendo.  When a representative of MCC asked the lab the best way to  
invest two million research dollars in VR, the answer was clear: give  
away forty $50,000 systems.

The most complex, and potentially dangerous, risk is what we are  
calling cognitive remodeling.  Those who spend a lot of time in VR  
bring back to physical reality some strange habits, like navigating  
across a room by pointing,  like bumping into walls cause they aren't  
just images, like dreaming in polygons.  VR effects dreaming  
strongly, it seems to provide tools for control of the dreamlife from  
within the dream.  VR changes mental models.  Now, it is not  
dangerous that this is happening, cause all intense work produces  
similar effects.  Anyone who has programmed all night will know that  
the programming slips into dreams.  The problem is not that these  
things happen, it is that we don't have the faintest clue what is  
going on.  We do not know the borders between virtual and actual.  We  
have not yet had the opportunity to evaluate current theories of  
reality crossing.

And how will we react when we are able to redefine our bodies, swap  
our perspectives, mix our senses.  We will have the ability to map  
arbitrarily across sensory input, self-image, and behavioral output.   
What will a fluid self be like?  We will need to understand the  
cognitive and behavioral effects of transportable perspectives, of  
programmable bodies, of synesthetic sensations, of exchangable body  
parts, of inhabiting arbitrary objects, of masslessness, of  
negotiable communality, of complete empowerment.

Are there limits to the degree of warpage our senses can tolerate?   
This is, of course, an empirical question.  What are the functional  
constraints of sensory modification for enhanced productivity, for  
enhanced enjoyment?  Are there sensory pathways to insanity or to  
ecstasy?  Just which side of the monitor do you stand on?

We have been discussing a domain which emphasizes personal freedom.   
VR could be used for horrible purposes, but that negative assumes  
that we are strapped to a chair.  So long as each individual has the  
freedom to reach up and turn off the experience, VR itself is quite  
benign.  But how will authority respond to this frontier?  VR is  
interactive, but will I have the right to remove the virtual arches  
in my prebuilt reality given away with each hamburger?   Are  
advertisements from the creator necessarily non-interactive?   Where  
are the edges of property and ownership in a world which is digital?   
Will there be commodities?  What are the rights of autonomous  
computational entities?  Will there be stability?  Will there be a  
Virtual Environmental Protection Agency?  I don't know, but I  
certainly look forward to negotiating the communal rules of personal  
responsibility in cyberspace.  


The biggest issue is how our culture will respond to this new  
reality.  We have amassed hundreds of years of favoritism for the  
objective, the scientific.  Our values, ethics, and aesthetics are  
predisposed toward Objectivism.  Is VR a better place for transacting  
information?  How will physical reality react to competition?  What  
will socialization without material consequence be like?  What kind  
of intimacy will arise from explicitly penetrating world views?  What  
kind of cultures will arise when the VR network is standardized?  Are  
we like Columbus, discovering a completely new land in an unexpected  
place?  Is living in VR necessarily pathological?  These are indeed  
exciting times. 



XI.  EVOLVING PHILOSOPHIES

We have come very close to talking about philosophy, so here are some  
comments on philosophical concepts:

	situated semantics
	pervasion
	immaterial realism
	constructivism
	boundary mathematics
	more than reality

Situated activity is a growing school of thought in AI.  The idea is  
simple:  what we do depends on our environment as well as our  
internal state.  We react and respond, constantly bringing external  
context into our interpretation of the moment.  Currently, symbolic  
logic is split in half, between syntax  (representation) and  
semantics (meaning).  Syntax is strictly formal, it has no basis in  
experience.  Semantics attempts to connect syntactic symbols to the  
reality of the world by mapping representation onto meaning.   The  
problem is that it does so without regard to context external to the  
formal symbols.  Since environments necessarily introduce external  
unknowns, standard semantics is just too literal.  Situated activity  
is an attempt to build a theory of context.  


VR, in comparison, is totally situated.  By defining natural behavior  
as the rules of interaction, by displaying recognizable spatial  
structures as output,  by providing context in toto, and by including  
the participant, VR redefines the relation between syntax and  
semantics.  Semantics, what we consider to be anchored to reality, is  
displayed directly as (virtual) reality.  Syntax, the symbols that  
guide computational activity, is hidden in the background, out of  
sight.

Environments include their participants, they pervade their contents.   
Pervasion is a non-dualistic concept, more familiar to Buddhism than  
to Christianity.   A pervasive space is one which is diffused  
throughout every part of itself, including those parts occupied by  
other spaces and objects.  Objects themselves are those boundaries of  
spaces that we can sense.  When we look at the container of an  
environment, from the outside, we see that it surrounds a portion of  
space.  The important point to understand is that environments focus  
our attention on a particular portion of space, they do not separate  
space into two opposite parts.   The outside space still pervades the  
inside space.  For VR, the physical pervades the virtual.  When we  
enter a virtual world, we always bring our physical body.  VR is not  
a separate reality, in a dualistic sense, it is a pervaded reality.   
The shift from duality to pervasion is from networks to maps, from  
separation to unity, from confrontation to cooperation, from male to  
female, from one to zero.

The Copernican revolution introduced a physics that differed  
fundamentally from appearance.  VR introduces a metaphysics that  
differs fundamentally from the material.  At the foundation of  
Objectivism is an attempt to be realistic about the material world.   
VR calls for immaterial realism, for being realistic about  
information.  The currency of VR is organization, not possession, not  
accumulation, not territory.  All laws are transmutable, we can  
satisfy fantasy rather than fact.  It is science itself that is  
redefined.  In VR, we can choose to be reductionalist, but at the  
bottom of it all, there is not Mass or Nature,  there is the Void.   
VR is representational, but not a priori rational, empirical, or  
verifiable.  VR is illogical positivism:  if you can specify it, it  
is meaningful.  All empirical hypotheses are true.

Another fundamental philosophical position engendered by VR is that  
of constructivism, that our minds and our bodies coparticipate in  
defining reality.  Objectivism places an overemphasis on the input of  
the physical body.  Solipsism overemphasizes the mind.   
Constructivism recognizes that reality is like light, it is both  
particle and wave, both objective and cognitive, both observation and  
participation.  In VR, we cannot escape the realization that we are  
the architects of our environment.

We are applying boundary mathematics to VR in three different ways:   
as a foundational mathematics, as a technique for logical deduction  
and maintenance of inconsistency, and as a spatial embodiment of  
abstract concepts.

Boundary mathematics is a calculus of inclusion.   The essence of VR  
is inclusion, the relationship between an environment and a  
participant.  The primitives of boundary mathematics are also  
participant and environment.  Let (  ) represent an environment, and  
let i represent a participant.  A variation of Spencer Brown's Laws  
of Form provides the axiomatic basis:  

	Observe:          i  (   )  =  (   )
	Participate:       (  i  )  =       

The left-hand-side of each equation is descriptive (objective),  
explicitly mentioning the participant.  The right-hand-side is  
experiential (participatory), implicitly using the participant's  
perspective.  We read the left-hand-side from our traditional  
externalized, objective perspective.  The right-hand-side refers to  
our experience, from the subjective perspective.  When we observe an  
empty environment, we perceive its boundary.  When we are included in  
an otherwise empty environment, we perceive emptiness.  That's all  
there is at the foundations of experience.

The most important thing to realize about VR is that it is more than  
reality, more than a simulation of reality.  You add physical realism  
to a virtual world by adding constraints that reduce the  
possibilities in that world.  Native VR lets you walk through walls,  
we add collision detection to disallow this power.  Native VR has no  
gravity, we add gravitational equations to simulate a gravitational  
reality.  Reality simulation is a subset of potential VR experiences.   
The least elaborated virtual world is the Void.

We describe innovations in terms of what they replace.  Only after  
decades do we come to understand the pervasive impact of new  
technologies on our culture. The automobile was first the horseless  
carriage.  It replaced the carriage, looked like a carriage, and  
moved at the speed of a horse.  Decades later, the automobile has  
transformed our landscapes, the pace of our travels, and our concepts  
of time and space. The television replaced the radio.  Television  
programs were first radio programs with pictures.  Decades later, the  
television has transformed our evenings, the pace of our senses, and  
our concepts of news and entertainment.  


The computer is first a symbol processor.  Although decades have  
barely passed, it is transforming our concepts of information and  
calculation.  Computers are thought to replace typewriters and  
desktops and filing cabinets.  But the computer has yet to be  
understood for what it is of itself, we still view it from the  
impoverished model of what it replaces.   McLuhan said that computers  
extend our central nervous system.  Our CNS is not a symbol  
processor, it is a generator of personal realities.  VR marks the end  
of the infancy of computation, the essence of the computer revolution  
is yet to come.   Essentially computers are reality generators.  


And reality is in the eye of the participant.