The Senses Have no Future
Hans Moravec
Robotics Institute
Carnegie Mellon University
Pittsburgh, PA 15213
hpm@cmu.edu
February 1997
Abstract
Senses evolved to when the world was wild, enabling our ancestors
to detect subtle passing opportunities and dangers. Senses are less
useful in a tamer world, where our interactions become more and more
simple information exchanges. Senses, and the instincts using them,
are increasingly liabilities, demanding entertainment rather than
providing useful services. The anachronism will become more apparent
as virtual realities, prosthetic sense organs and brain to computer
interfaces become common. Imagine reading a computer screen if your
eyes and visual cortex are artificial prostheses. It would be far
better to bypass all the sensory processing, and insert the message
from the computer directly into the thinking portions of your brain.
In such manner all our senses will become obsolete, as our physical
environment is inexorably refined from a rough physical place into a
densely interconnected cyberspace.
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The retina is a transparent, paper-thin layer of nerve tissue at
the back of the eyeball--on which the eye's lens projects an image of
the world--connected by a million-fiber cable--the optic nerve--to
regions deep in the brain. It is a part of the brain convenient for
study, even in living animals because of its peripheral location and
because its image-processing functions seem straightforward compared
with the brain's other mysteries. A human retina contains about 100
million neurons, of five distinct kinds. Light-sensitive cells feed
horizontal cells and bipolar cells, which connect to
amacrine cells, whose output goes to ganglion cells,
whose outgoing fibers bundle to form the optic nerve. Each of the
million ganglion-cell axons carries signals from a particular patch of
image, representing the differences in light intensity between
adjacent regions and from one time to the next--edge and motion
detections that are useful also in robot vision. Overall, the retina
seems to resolve about one million distinct regions in the visual
field and to follow change up to about ten frames per second. Fed a
video image with similar resolution, it takes a robot vision program
about 100 computer operations to produce a single edge or motion
detection, thus 100 million operations to match a whole "frame" of
optic nerve output, and 1,000 MIPS--the power of a small
supercomputer--to equal the retina's ten frames per second.
If the retina is worth 1,000 MIPS, what about the whole brain,
whose larger neurons are 1,000 times as numerous, but occupy 100,000
times the volume? Multiplying the retina's computation by a
compromise brain/retina ratio of 10,000 yields a rough brain
equivalent of 10 million MIPS--like a million 1997 robot computers, or
100 of the biggest supercomputers. Conversely a 10 MIPS robot--like
most still in use--has the mental power of a million-neuron bee. An
advanced experimental robot, with 100 MIPS, matches the brain of a
very small fish. The Figure 2 rates other entities. In fact, the
narrowly competent performace of advanced industrial robots that do
intricate assembly of electronics, and of experimental robots that
drive the autobahns, has the character of a small animal.
Technological development has taken us from the equivalent of single
neurons to this stage in about 70 years. It took natural evolution
about 700 million years to go as far - evolving humans from there
required a few hundred million more. By analogy it should take
technology a few decades to cover the remaining distance. Computer
progress supports this timescale.
Computers have doubled in capacity every two years since 1950, a
pace that has becom an industry given. The curve steepened in the
1990s, to doubling each year, as seen in Figure 2. The universal
factor in improving computation has been miniaturization: smaller
components have less inertia and operate more quickly with less power,
and more of them can exist in a given space. Microprocessors in 1997
contain about 10 million components, but manufacturers have exhibited
memory chips with a billion devices. As components shrink to atomic
scales, it is possible to imagine two-dimensional chips with a
trillion components, and three-dimensional arrays with a million
trillion. Such numbers take us far beyond the paltry 10 million MIPS
required for a human-capable robot. The--probably
conservative--assumption that computer power will continue to grow at
its historical rate predicts that 10 million MIPS personal computers
will arrive by 2030. Giving the robotics industry a few years to get
its software into shape, suggests the advent of human-like robots soon
after.
FIGURE 1: Natural and Artificial Thinkers
FIGURE 2: Faster-than-exponential Growth in Computing Power
As intelligent robots design successive generations of
successors, technical evolution will go into overdrive. Biological
humans can either adopt the fabulous mechanisms of robots, thus
becoming robots themselves, or they can retire into obscurity. A
robot ecology will colonize space with intelligent machines optimized
to live there. Yet, viewed from a distance, robot expansion into the
cosmos will be a vigorous physical affair, a wavefront that converts
raw inanimate matter into mechanisms for further expansion. It will
leave in its ever-growing wake a more subtle world, with less action
and more thought.
On the frontier, robots of ever increasing mental and physical
ability will compete with one another in a boundless land rush.
Behind the expansion wavefront, a surround of established neighbors
will restrain growth, and the contest will become one of boundary
pressure, infiltration and persuasion: a battle of wits. A robot with
superior knowledge of matter may encroach on a neighbor's space
through force, threat, or convincing promises about the benefits of
merger. A robot with superior models of mind might lace attractive
gifts of useful information with subtle slants that subvert others to
its purposes. Almost always, the more powerful minds will have the
advantage.
To stay competitive, robots will have to grow in place, repeatedly
restructuring the stuff of their bounded bodies into more refined and
effective forms. Inert lumps of matter, along with limbs and sense
organs, will be converted into computing elements, whose components
will be then miniaturized to increase their number and speed.
Physical activity will gradually transform itself into a web of
increasingly pure thought, where every smallest action is a meaningful
computation. We cannot guess the mechanisms robots will use, since
physical theory has not yet found even the exact rules underlying
matter and space. Having found the rules, robots may use their
prodigious minds to devise highly improbable organizations that are to
familiar elementary particles as knitted sweaters are to tangled balls
of yarn.
As they arrange space time and energy into forms best for
computation, robots will use mathematical insights to optimize and
compress the computations themselves. Every consequent increase in
their mental powers will accelerate future gains, and the inhabited
portions of the universe will be rapidly transformed into a
cyberspace, where overt physical activity is imperceptible, but the
world inside the computation is astronomically rich. Beings will
cease to be defined by their physical geographic boundaries, but will
establish, extend and defend identities as informational transactions
in the cyberspace. The old bodies of individual robots, refined into
matrices for cyberspace, will interconnect, and the minds of robots,
as pure software, will migrate among them at will. As the cyberspace
becomes more potent, its advantage over physical bodies will overwhelm
even on the raw expansion frontier. The robot wavefront of coarse
physical transformation will be overtaken by a faster wave of
cyberspace conversion, the whole becoming finally a bubble of Mind
expanding at near lightspeed.
State of Mind
The cyberspace will be inhabited by transformed robots, moving and
growing with a freedom impossible for physical entities. A good, or
merely convincing, idea, or an entire personality, may spread to
neighbors at the speed of light. Boundaries of personal identity will
be very fluid, and ultimately arbitrary and subjective, as strong and
weak interconnections between different regions rapidly form and
dissolve. Yet some boundaries will persist, due to distance,
incompatible ways of thought, and deliberate choice. The consequent
competitive diversity will allow a Darwinian evolution to continue,
weeding out ineffective ways of thought, and fostering a continuing
novelty.
Computational speedups will extend the amount of future available
to cyberspace inhabitants, because they cram more events into a given
physical time, but will have only a subtle effect on immediate
existence, since everything, inside and outside the individual, will
be equally accelerated. Distant correspondents, however, will seem
even more distant, since more thoughts will transpire in the unaltered
transit time for lightspeed messages. Also, as information storage is
made more efficient through both denser utilization of matter and more
efficient encodings, there will be increasingly more cyber-stuff
between any two points. The overall effect of improvements in
computational efficiency is to increase the effective space, time and
material available, that is, to expand the universe.
Because it uses resources more efficiently, a mature cyberspace
will be effectively much bigger and longer lasting than the raw
spacetime it displaces. Only an infinitesimal fraction of normal
matter does work of interest to thinking beings, but in a
well-developed cyberspace every bit will be part of a relevant
computation or storing a significant datum. The advantage will grow
as more compact and faster ways of using space and matter are
invented. Today we take pride in storing information as densely as
one bit per atom, but it is possible to do much better by converting
an atom's mass into many low-energy photons, each storing a separate
bit. As the photons' energies are reduced, more of them can be
created, but their wavelength, and thus the space they occupy and the
time to access them rises, while the temperature they can tolerate
drops. A very general quantum mechanical calculation in this spirit
by Bekenstein concludes that the maximum amount of information stored
in (or fully describing) a sphere of matter is proportional to the
mass of the sphere times its radius, hugely scaled. The "Bekenstein
bound" leaves room for a million bits in a hydrogen atom, 10^16 in a
virus, 10^45 in a human being, 10^75 for the earth, 10^86 in the solar
system, 10^106 for the galaxy, and 10^122 in the visible
universe.
The computer to brain comparison above suggests that a human brain
could be encoded in less than 10^15 bits. If it takes a thousand
times more storage to encode a body and surrounding environment, a
human with living space might consume 10^18 bits, and a large city of
a million human-scale inhabitants might be efficiently stored in 10^24
bits, and the entire existing world population would fit in 10^28.
Thus, in an ultimate cyberspace, the 10^45 bits of a single human body
could contain the efficiently-encoded biospheres of a thousand
galaxies--or a quadrillion individuals each with a quadrillion times
the capacity of a human mind.
Because it will be so more capacious than the conventional space
it displaces, the expanding bubble of cyberspace can easily recreate
internally everything of interest it encounters, memorizing the old
universe as it consumes it. Traveling as fast as any warning message,
it will absorb astronomical oddities, geologic wonders, ancient
Voyager spacecraft, early robots in outbound starships and entire
alien biospheres. Those entities may continue to live and grow as if
nothing had happened, oblivious of their new status as simulations in
the cyberspace--living memories in unimaginably powerful minds, more
secure in their existence, and with more future than ever before,
because they have become valued parts of such powerful
patrons.
Earth, at the center of the expansion, can hardly escape the
transformation. The conservative, somewhat backward, robots defending
Earth from unpredictable robots will be helpless against a wave that
subverts their very substance. Perhaps they will continue, as
simulations defending a simulated Earth of simulated biological
humans--in one of many, many different stories that plays itself out
in the vast and fertile minds of our ethereal grandchildren.
The scenarios absorbed in the cyberspace expansion will provide
not only starting points for unimaginably many tales about possible
futures, but an astronomically voluminous archeological record from
which to infer the past. Minds somewhere intermediate between
Sherlock Holmes and God will process clues in solar-system quantities
to deduce and recreate the most microscopic details of the preceding
eras. Entire world histories, with all their living, feeling
inhabitants, will be resurrected in cyberspace. Geologic ages,
historical periods and individual lifetimes will recur again and again
as parts of larger mental efforts, in faithful renditions, in artistic
variations, and in completely fictionalized forms.
The Minds will be so vast and enduring, that rare infinitesimal
flickers of interest by them in the human past will ensure that our
entire history is replayed astronomically many times, in many places
and many, many variations. Single original events will be very rare
compared to the indefinitely many cyberspace replays. Most things
that are experienced--this very moment, for instance, or your entire
life--are far more likely to be a Mind's musings than the physical
processes they seem to be. There is no way to tell for sure, and the
suspicion that we are someone else's thought does not free us from the
burdens of life: to a simulated entity, the simulation is reality, and
must be lived by its internal rules.
Pigs in Cyberspace?
Might an adventurous human mind escape from a bit role in a cyber
deity's thoughts, to eke out an independent life among the mental
behemoths of a mature cyberspace? We approach the question by
extrapolating existing possibilities.
Telepresence and virtual reality are in the news. Today's
pioneering systems give crude peeks into remote and simulated worlds,
but maturing technology will improve the fidelity. Imagine a
well-developed version of the near future: you are cocooned in a
harness that, with optical, acoustical, mechanical, chemical and
electrical devices drives all your senses, and measures all of your
actions. The machinery presents pictures to your eyes, sounds to your
ears, pressures and temperatures to your skin, forces to your muscles
and even smells and tastes to your nose and mouth. Telepresence
results when these inputs and outputs are relayed to a distant
humanoid robot. Images from the robot's two camera eyes appear on
your eyeglass viewscreens, sound from its microphones is heard in your
earphones, contacts on your skin allow you to feel through its
instrumented surface and smell and taste through its chemical sensors.
Motions of your body cause the robot to move in exact synchrony. When
you reach for something in the viewscreens, the robot grasps it, and
relays to your muscles and skin the resulting weight, shape, texture
and temperature, creating the perfect illusion that you inhabit the
robot's body. Your sense of consciousness seems to have migrated to
the robot's location, in a true "out of body" experience.
Virtual reality uses a telepresence harness, but substitutes a
computer simulation for the remote robot. When connected to a virtual
reality, where you are and what you see and touch do not exist in the
usual physical sense, but are a kind of computer-generated dream.
Like human dreams, virtual realities may contain elements from the
outside world, for instance representations of other physical people
connected via their own harnesses, or even real views, perhaps through
simulated windows. Imagine a hybrid travel system, where a virtual
"central station" is surrounded by portals with views of various
physical locations. While in the station one inhabits a simulated
body, but as one steps through a portal, the harness link switches
seamlessly to a physical telepresence robot waiting at that
location.
Linked realities are crude toys today, but driven by rapidly
advancing computer and communications technologies. In a few decades
people may spend more time linked than experiencing their dull
immediate surroundings, just as today most of us spend more time in
artificial indoor settings than in the uncomfortable outdoors. Linked
realities will routinely transcend the physical and sensory
limitations of the "home" body. As those limitations become more
severe with age, we might compensate by turning up a kind of volume
control, as with a hearing aid. When hearing aids at any volume are
insufficient, it is now possible to install electronic cochlear
implants that stimulate auditory nerves directly. Similarly, on a
grander scale, aging users of remote bodies may opt to bypass
atrophied muscles and dimmed senses, and connect sensory and motor
nerves directly to electronic interfaces. Direct neural interfaces
would make most of the harness hardware unnecessary, along with sense
organs and muscles, and indeed the bulk of the body. The home body
might be lost, but remote and virtual experiences could become more
real than ever.
Picture a "brain in a vat," sustained by life-support machinery,
connected by wonderful electronic links to a series of artificial
rent-a-bodies in remote locations, and to simulated bodies in virtual
realities. Though it may be nudged far beyond its natural lifespan by
an optimal physical environment, a biological brain built to operate
for a human lifetime is unlikely to function effectively forever. Why
not use advanced neurological electronics like that which links it
with the external world, to replace the gray matter as it begins to
fail? Bit by bit our failing brain may be replaced by superior
electronic equivalents, leaving our personality and thoughts clearer
than ever, though, in time, no vestige of our original body or brain
remains. The vat, like the harness before it, will have been rendered
obsolete, while our thoughts and awareness continue. Our mind will
have been transplanted from our original biological brain into
artificial hardware. Transplantation to yet other hardware should be
trivial in comparison. Like programs and data that can be transferred
between computers without disrupting the processes they represent, our
essences will become patterns that can migrate the information
networks at will. Time and space will be more flexible--when our mind
resides in very fast hardware, one second of real time may provide a
subjective year of thinking time, while a thousand years spent on a
passive storage medium will seem like no time at all. The very
components of our minds will follow our sense of awareness in shifting
from place to place at the speed of communication. We might find
ourselves distributed over many locations, one piece of our mind here,
another piece there, and our sense of awareness yet elsewhere , in
what can no longer be called an out-of-body experience, for lack of a
body to be out of. And, yet, we will not be truly disembodied
minds.
Humans need a sense of body. After twelve hours in a
sensory-deprivation tank, floating in a totally dark, quiet,
contactless, odorless, tasteless, body-temperature saline solution, a
person begins to hallucinate, as the mind, like a television
displaying snow on an empty channel, turns up the amplification in
search of a signal, becoming ever less discriminating in the
interpretations it makes of random sensory hiss. To remain sane, a
transplanted mind will require a consistent sensory and motor image,
derived from a body, or from a simulation. Transplanted human minds
will often be without physical bodies, but hardly ever without the
illusion of having them.
Computers already contain many non-human entities that resemble
truly bodiless minds. A typical computer chess program knows nothing
about physical chess pieces or chessboards, or about the staring eyes
of its opponent or the bright lights of a tournament, nor does it work
with an internal simulation of those physical attributes. It reasons,
instead, with a very efficient and compact mathematical representation
of chess positions and moves. For the benefit of human players, this
internal representation may be interpreted into a graphic on a
computer screen, but such images mean nothing to the program that
actually chooses the chess moves. The chess program's thoughts and
sensations--its consciousness--is pure chess, uncomplicated by
physical considerations. Unlike a transplanted human mind requiring a
simulated body, a chess program is pure mind.
Minds in a mature, teeming, competitive cyberspace will be
optimally configured to make their living there. Only successful
enterprises will be able to afford the storage and computational
essentials of life. Some may do the equivalent of construction,
converting undeveloped parts of the universe into cyberspace, or
improving the performance of existing patches, thus creating new
wealth. Others may devise mathematical, physical or engineering
solutions that give the developers new and better ways to construct
computing capacity. Some may create programs that others can
incorporate into mental repertoire. There will be niches for agents,
who collect commissions for locating opportunities and negotiating
deals for clients, and for banks, storing and redistributing
resources, buying and selling computing space, time and information.
Some mental creations will be like art, having value only because of
changeable idiosyncrasies in their customers. Entities who fail to
support their operating costs will eventually shrink and disappear, or
merge with other ventures. Those who succeed will grow. The closest
present-day parallel is the growth, evolution, fragmentation and
consolidation of corporations, who plan their future, but whose
options are shaped primarily by the marketplace.
A human would likely fare poorly in such a cyberspace. Unlike the
streamlined artificial intelligences that zip about, making
discoveries and deals, rapidly reconfiguring themselves to efficiently
handle changing data, a human mind would lumber about in a massively
inappropriate body simulation, like a deep-sea diver plodding through
a troupe of acrobatic dolphins. Every interaction with the world
would first be analogized into a recognizable quasi-physical form:
other programs might be presented as animals, plants or demons, data
items as books or treasure chests, accounting entries as coins or
gold. Maintaining the fictions will increase the cost of doing
business and decrease responsiveness, as will operating the mind
machinery that reduces the physical simulations into mental
abstractions in the human mind. Though a few humans may find
momentary niches exploiting their baroque construction to produce
human-flavored art, most will be compelled to streamline their
interface to the cyberspace.
The streamlining could begin by merging processes that analogize
the world with those that reduce the resulting simulated sense
impressions. The cyber world would still appear as location, color,
smell, faces, and so on, but only noticed details would be
represented. Since physical intuitions are probably not the best way
to deal with most information, humans would still be at a disadvantage
to optimized artificial intelligences. Viability might be further
increased by replacing some innermost mental processes with
cyberspace-appropriate programs purchased from the AIs. By a large
number of such substitutions, our thinking procedures might be totally
liberated from any traces of our original body. But the bodiless mind
that results, wonderful though it may be in its clarity of thought and
breadth of understanding, would be hardly human: it will have become
an AI.
So, one way or another, the immensities of cyberspace will be
teeming with unhuman superminds, engaged in affairs that are to human
concerns as ours are to those of bacteria. Memories of the human past
will occasionally flash through their minds, as humans once in a long
while think of bacteria, and by their thoughts they will recreate us.
They could interface us to their realities, making us something like
pets, though we would probably be overwhelmed by the experience. More
likely, the re-creations would be in the original historical settings,
fictional variations, or total fantasies, which would to us seem just
like our present existence. Reality or re-creation, there is no way
to sort it out from our perspective: we can only wallow in the scenery
provided.
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Biography for Hans Moravec
Hans Moravec has been thinking about machines thinking since he
was a child in the 1950s, builing his first robot, a construct of tin
cans, batteries, lights and a motor, at age ten. In high school he
won two science fair prizes for a light-following electronic turtle
and a tape-controlled robot hand. As an undergraduate he designed a
computer to control fancier robots, and experimented with learning and
automatic programming on commercial machines. During his master's
work he built a small robot with whiskers and photoelectric eyes
controlled by a minicomputer, and wrote a thesis on a computer
language for artificial intelligence. He received a PhD from Stanford
in 1980 for a TV-equipped robot, remote controlled by a large
computer, that negotiated cluttered obstacle courses. Since 1980 he
has been director of the Carnegie Mellon University Mobile Robot
Laboratory, birthplace of mobile robots deriving 3D spatial awareness
from cameras, sonars, and other sensors. His 1988 book, "Mind
Children: the future of robot and human intelligence", and
forthcomg "Mind Age: transcendence through robots", consider
the future prospects for humans, robots and intelligence. He has
published many articles in robotics, computer graphics,
multiprocessors, space travel and other speculative areas.