Dorling, D. (1991) PhD Thesis: The Visualization of Spatial Social Structure,
University of Newcastle upon Tyne.
Scans of the prints referred to can be found here:
The Visualization of Spatial Social Structure
Thesis submitted for the
degree of Doctor of Philosophy to
the University of Newcastle upon Tyne,
Daniel F. L. Dorling
A great deal of information about the social geography of Britain is
contained within databases such as the census. To comprehend this
information it needs to be effectively visualized. Conventional maps
contain an unwanted distortion however, and have been rejected by many
as an unsuitable means of showing spatial social structure. A more human
cartography is developed here to show the events of people's lives and the
shape of society. This thesis argues that a truer picture is obtained by being
able to see the whole, in as much detail as possible, at a glance.
A total of 179 high resolution prints show original techniques to study
many aspects of life in Britain today. They include pictures of the
distribution of age, sex, birthplace and occupation in 1981, changes in
these from 1971, unemployment and house price dynamics throughout the
1980s, general election results from 1955 to 1987 (followed by all local
election voting from 1987 to 1990), migration flows from one part of the
country to another and daily commuting streams. These are of interest for
the various methods of visualization used, their content, and the extremely
high levels of detail achieved. Over ten thousand places are shown in most
of the images produced.
Much of the work involved the creation of computer generated cartograms
where each areal unit (up to one hundred thousand to a page) is drawn in
proportion to the number of people who live there. Colour and complex
symbols are used to study several factors simultaneously and visually
effective means of showing millions of flows and other changes over time
are developed. A case study of the distribution of childhood leukaemia in
space and time is also undertaken. Tables give the detailed results of the
last ten general elections (with a basis for dealing with constituency
boundary changes). The algorithm to create a detailed cartogram is
presented and an index is included.
To Benjamin Dorling
List of Figures
List of Prints
Introduction: Human Cartography
Chapter 1: Envisioning Information
1.1 Visual Thinking
1.2 Pictures Over Time
1.3 Beyond Illustration
1.4 Texture and Colour
1.5 Perspective and Detail
1.6 Pattern and Illusion
1.7 From Mind to Mind
Chapter 2: People, Spaces and Places
2.1 Which People
2.2 Why Study Places?
2.3 What Are Spaces?
2.4 Drawing Lines
2.5 Picturing Points
2.6 Population Space
2.7 Adding Time
Chapter 3: Artificial Reality
3.1 Imagining Reality
3.2 Abstract Spaces
3.3 Area Cartograms
3.4 The Nature of Space
3.5 Producing Illusions
3.6 Population Space
3.7 Stretching Spacetime
Chapter 4: Honeycomb Structure
4.1 Viewing Society
4.2 Who the People Are
4.3 Disparate Origins
4.4 Lost Opportunities
4.5 Work, Industry and Home
4.6 How People Vote
4.7 The Social Landscape
Chapter 5: Transforming the Mosaic
5.1 Still Images of Change
5.2 Forming the Structure
5.3 Structure Transformed
5.4 Variable Employment
5.5 House Price Inflation
5.6 Reshaping Votes
5.7 Erosion and Deposition
Chapter 6: Cobweb of Flows
6.1 What Flow Is
6.2 What Flows There Are
6.3 Unravelling the Tangles
6.4 Drawing the Vortices
6.5 Commuting Chaos
6.6 Migration Networks
6.7 A Space of Flows
Chapter 7: On the Surface
7.1 2D Vision, 3D World
7.2 Surface Definition
7.3 Depth Cues
7.4 Landscape Painting
7.5 Surface Geometry
7.6 Travel Time Surface
7.7 Surface Value
Chapter 8: The Wood and the Trees
8.1 Sculptured Characters
8.2 Circles, Pies and Rings
8.3 Bars and Pyramids
8.4 Flocks of Arrows
8.5 Trees and Castles
8.6 Crowds of Faces
8.7 Information Overload
Chapter 9: Volume Visualization
9.1 The Third Dimension
9.2 Spaces, Times and Places
9.3 Spacetime Continuum
9.4 Three Dimensional Graphs
9.5 Flows Through Time
9.6 Volume Rendering
9.7 Interactive Visualization
Conclusion: Another Geography
Appendix A: Circular Cartogram Algorithm
Appendix B: Parliamentary Constituencies 1955-1987 Continuity
Appendix C: Parliamentary Constituencies 1955-1987 Results
Appendix D: Average Housing Price by Constituency 1983-1989
Appendix E: Scottish Ward to Postcode Sector Look-up Table
Appendix F: Local Government Wards, 1981 and 1987
List of Figures
Figure 1: Creating the Graphics
Figure 2: Printing in Colour
Figure 3: Recording the Places
Figure 4: Drawing the Maps
Figure 5: Storing the Geometry
Figure 6: The Areal Hierarchy
Figure 7: The Mercator Projection
Figure 8: The Algorithm at Work
Figure 9: Deriving a Constant
Figure 10: Many-dimensional Cartograms
Figure 11: Storing the Census
Figure 12: Working Definitions
Figure 13: Two-dimensional Smoothing
Figure 14: Linking the Censuses
Figure 15: How Closely Connected?
Figure 16: Measuring the Changes
Figure 17: Storing the Flows
Figure 18: A Significant Flow
Figure 19: Drawing Overlapping Arrows
Figure 20: The Electoral Triangle
Figure 21: The Perspective Projection
Figure 22: Travel Time Surface
Figure 23: Areal Interpolation
Figure 24: Trees and Pyramids
Figure 25: Constructing Face Glyphs
Figure 26: Three-dimensional Smoothing
Figure 27: The Electoral Tetrahedron
Figure 28: Three-dimensional Structure
Figure 29: References Over Time
List of Prints
Two images from the infinity of the Mandelbrot set (Colour).
Land use close-up of Northern Britain (Colour).
Journey to work flows of over ten people between wards from the 10% sample.
The changing distribution of housing by price, attributes and sales, 1983-1987.
Migration flows between all regions in 1976 — flows sorted by contiguity order.
Yearly migration flows between English and Welsh wards 1980/1981.
The changing distribution of age and gender in Britain 1971-1981 (Colour).
Voting composition on the electoral cartograms of Northern Britain (Colour).
Voting composition on the electoral cartograms of Southern Britain (Colour).
The distribution of employment by industry, status and gender (Colour).
Stills from a conventional animation of the computer (Colour).
Stills from a ray-traced animation of the computer (Colour).
Ray-traced surfaces of the Mandelbrot and Julia sets.
Visualizing Fourier transforms — the art in the science (Colour).
A maze of colour — the detail a low resolution image can show (Colour).
Visualization of the Mandelbrot set — magnification and generalization (Colour).
Travel time from the Tyneside road network (Colour).
Three alternative colour schemes and keys (Colour).
The concentration of British born place of birth (Colour).
The distributions of population, age, gender and children in London (Colour).
The distributions of place of birth in London (Colour).
The distributions of employment, occupation and graduates in London (Colour).
The distribution of broad industrial groups in Britain, 1987 (Colour).
The changing distribution of broad industrial groups, 1984-87, increases (Colour).
The changing distribution of broad industrial groups, 1984-87, decreases (Colour).
The change in employment by industry, status and gender, 1984-1987 (Colour).
Political swing on the electoral cartograms of Northern Britain (Colour).
Political swing on the electoral cartograms of Southern Britain (Colour).
The distribution of voting in English and Welsh local elections (Colour).
Land use in Britain by 1km square grid (Colour).
Level II European Regions — annotated base map shaded by unemployment rate.
Counties and Scottish Regions — annotated base map shaded by unemployment rate.
Family Practitioner Committee Areas — annotated base map shaded by unemployment rate. 33
Local Education Authorities — annotated base map shaded by unemployment rate.
“Functional Cities” — annotated base map shaded by unemployment rate.
Local Labour Market Areas — annotated base map shaded by unemployment rate.
Travel-to-work Areas — annotated base map shaded by unemployment rate.
Local government districts — annotated base map shaded by unemployment rate.
Parliamentary Constituencies — annotated base map shaded by unemployment rate.
Amalgamated Office Areas — annotated base map shaded by unemployment rate.
Postcode Areas — coloured at random (Colour).
Postcode Districts — coloured at random (Colour).
Postcode Sectors — coloured at random (Colour).
The British mainland rail network on an equal land area projection.
The British mainland rail network on an equal population projection.
The British primary road network on an equal land area projection.
The British primary road network on an equal population projection.
Experiments with area cartograms (Colour).
Continuous area cartograms of the British population (Colour).
County boundaries showing bridges which maintain ward continuity.
The evolution of a cartogram of population by County.
The County population cartogram with arrows representing topology.
Local authority districts on an equal land area projection indexed for identification.
Local authority districts — indexed list in alphabetical order.
Local authority districts cartogram indexed for identification.
Parliamentary Constituencies on an equal area projection indexed for identification.
Parliamentary Constituencies — indexed, list in alphabetical order.
Parliamentary Constituency cartogram indexed for identification.
Census wards — 1981 resident population area cartogram.
The concentration of unemployment by ward.
The distribution of unemployment by ward.
Counties and Scottish regions — four colour map.
Counties and Scottish Regions on the enumeration district cartogram.
Enumeration district population cartogram.
1981 equal population grid squares.
1981 population enumeration district cartogram showing the national grid.
The changing distribution of total population in Britain, 1971-1981.
The distribution of age and gender in Britain, 1981 (Colour).
The concentration of age and gender in Britain, 1981 (Colour).
The distribution of children by age in Britain, 1981 (Colour).
The distribution of Irish born in Britain, 1981.
The distribution of British born place of birth, 1981 (Colour).
The distribution of Overseas born place of birth, 1981 (Colour).
The concentration of Overseas born place of birth, 1981 (Colour).
The distribution of employment in Britain, 1981 (Colour).
The concentration of employment in Britain, 1981 (Colour).
The distribution of occupation in Britain, 1981 (Colour).
The concentration of occupation in Britain, 1981 (Colour).
The distribution of graduates in Britain, 1981 (Colour).
The distribution of housing price in Britain, 1983.
The distribution of voting in the 1987 British general election (Colour).
The map of voting in the 1987 British general election (Colour).
The distribution of first placed parties in the 1987 British general election (Colour).
The distribution of second placed parties in the 1987 British general election (Colour).
The distribution of non-voting in the 1987 British general election.
The distribution of voting composition in the 1987 British local elections (Colour).
The changing distribution of British born place of birth, 1971-1981.
The changing distribution of overseas born place of birth, 1971-1981 (Colour).
The changing distribution of employment in Britain, 1971-1981 (Colour).
The space/time trend of unemployment in Britain by office areas, 1978-1990.
The space/time trend of unemployment in Britain by counties, 1978-1990.
The changing distribution of occupation in Britain, 1971-1981 (Colour).
The distribution of housing price inflation in Britain, 1983/1984.
The distribution of housing price inflation in Britain, 1984/1985.
The distribution of housing price inflation in Britain, 1985/1986.
The distribution of housing price inflation in Britain, 1986/1987.
The distribution of housing price inflation in Britain, 1987/1988.
The distribution of housing price inflation in Britain, 1988/1989.
The distribution of housing price in Britain, 1989.
Voting composition by constituency, 1955-1987 (Colour).
The distributions of first placed party, 1955-1987 (Colour).
The distributions of second placed party, 1955-1987 (Colour).
The distributions of non-voting by constituency, 1955-1987.
Migration flows between all regions in 1976, sorted by contiguity order.
Migration flows between metropolitan counties and other areas, 1975-1976.
Daily commuting flows on an equal land area projection in 1981.
Daily commuting flows on an equal population projection in 1981.
Daily commuting flows as a proportion of destination employees.
Daily commuting flows as a proportion of destination residents.
Daily commuting flows on an equal area projection by occupation, 1981 (Colour).
Daily commuting flows in population space by occupation, 1981 (Colour).
Migration flows between family practitioner areas of 1 in 200 people.
Migration flows between family practitioner areas of 1 in 300 people.
Migration flows between family practitioner areas of 1 in 500 people.
Migration flows between family practitioner areas of 1 in 1000 people.
Migration flows between family practitioner areas of 1 in 2000 people.
Migration flows between family practitioner areas of 1 in 2777 people.
Migration flows between family practitioner areas on an equal area projection.
Migration flows between English and Welsh counties on an equal area projection.
Yearly migration flows on an equal area projection by occupation, 1981 (Colour).
Yearly migration flows in population space by occupation, 1981 (Colour).
The use of contours and colour to depict surface height (Colour).
The use of contours without colour to depict surface height.
British population surface showing the 1987 general election results (Colour).
British population two-way surface of the 1987 general election results (Colour).
The distribution of voting composition in the 1987 British general election (Colour).
CXXVII The national constituency voting compositions, 1955-1987 (Colour).
CXXVIII 1981 County council elections — English voting composition.
1985 County council elections — English voting composition.
1989 County council elections — English voting composition.
1981 County council elections — English voting composition surface.
CXXXII 1985 County council elections — English voting composition surface.
CXXXIII 1981/1985 County council elections — changing English voting composition surface.
CXXXIV 1989 County council elections — English voting composition surface.
CXXXV 1985/1989 County council elections —changing English voting composition surface.
CXXXVI 1981/85/89 County council elections —changing English voting composition surface.
CXXXVII The distribution of unemployment in Britain 1981— shown as a surface.
CXXXVIII The changing distribution of first place party in Britain, 1983-1987 (Colour).
CXXXIX The changing distribution of first place party in Britain, 1955-1987 (Colour).
The space/time trend of unemployment in Britain, 1978-1990.
The detailed national composition of industry in Britain, 1981
The changing national composition of industry in Britain, 1984-1987.
The distribution of employment by industry, status and gender, 1987.
The change in employment by industry, status and gender, 1984-1987.
The changing distribution of voting composition in Britain, 1983-87 (Colour).
The changing distribution of voting composition in Britain, 1955-87 (Colour).
CXLVII The distribution of housing by price, attributes and sales, 1987.
CXLVIII The distribution of housing by price, attributes and sales, 1987 (Colour).
The changing distribution of housing by price, attributes and sales, 1983/1987 (Colour).
Chernoff faces showing all permutations of five levels of four features.
The distribution of voting, housing, employment and industry in 1983 (Colour).
The distribution of voting, housing, employment and industry in 1987 (Colour).
The change in voting, housing, employment & industry, 1983-1987 (Colour).
The distribution of population by county in 1981 (Colour).
Population change in Britain by district, 1961-1991 (Colour).
The space/time trend of unemployment in Britain by cubes, 1978-1990.
The space/time trend of unemployment in Britain by rings, 1978-1990.
The distribution of years of highest house price inflation in Britain, 1983 to 1989.
The distribution of childhood leukaemia in Britain, 1966-1983 (Colour).
Six views of the childhood leukaemia spacetime distribution, 1966-1986.
Key to cancer types shown by spheres in the spacetime diagrams (Colour).
The distribution of childhood cancers in Euclidean spacetime (Colour).
The distribution of childhood cancers in spacetime 1968-1979 (Colour).
The distribution of childhood cancers in spacetime 1980-1991 (Colour).
The distribution of childhood cancers in Teesside spacetime, from the east (Colour).
The distribution of childhood cancers in Teesside spacetime, from the west (Colour).
CLXVII The 1988 district election results: Scottish voting composition tetrahedron.
CLXVIII A schematic representation of four party voting compositions.
The 1988 district election results: Scottish voting composition unfolded.
Four perspective views of the 1988 Scottish district elections composition (Colour).
A ray-traced image of the 1988 Scottish district elections composition (Colour).
CLXXII The ward cartogram drawn using Theisson polygons.
CLXXIII The Transformed map of voting in the 1987 British general election (Colour).
CLXXIV Transforming the political map of northern Britain to population space (Colour).
CLXXV Transforming the political map of southern Britain to population space (Colour).
CLXXVI The distribution of non-voting by voting composition in the 1987 general election.
CLXXVII The distribution of non-voting in constituencies by voting composition, 1955-1987.
CLXXVIII The distribution of occupation in Britain, 1981, after binomial smoothing (Colour).
CLXXIX The distribution of voting composition in British local elections 1987-1990 (Colour).
This dissertation is about new ways of presenting and understanding
some of the vast amounts of information which have been collected
about our society. It is based on the premise that huge numbers of
figures, incomprehensible in themselves, could contain a lot of
information that is distorted, even lost, in conventional statistical
analysis and cartographic display. This work has used the hopes and
ideas of numerous sources as to how to visualize information about
society more effectively. Recent dramatic increases in computer
capability have allowed me to create images which would not have
been conceivable two or three years ago. The approach has been
experimental. I often had little idea what an image would look like on
screen or paper until it was actually produced. The illustrations
presented here are only a small selection of those created.
Many ideas and several themes are contained in this thesis. The text
describes the rationale for, and development of, a new way of
visualizing information in geographical research. Through the pictures
the methods are illustrated; mistakes, techniques and discoveries
shown. From the footnotes, which are largely quotations from a
disparate literature, the origins of many of the ideas can be found.
Time and again the suggestions of others to move in these directions
are cited. Through technical asides some of the practical realities of
the work are described. Through the illustrations and their legends, a
picture of what has been happening to Britain in recent years unfolds.
Many of the pictures justify an extended discussion, but I have aimed
to keep the commentary brief. I have not included much detail about
the computer software I have written and used because much of that is
dependant on a novel (but inexpensive) hardware configuration and
progress is so rapid that such knowledge is of only transient value.
Periodically I have commented on the changing political and social
geography of Britain that the mapping has revealed.
Numerous case studies are included. Questions concerning the
implications of the spread of people in time and space are addressed at
many points. The patterns through ten British general elections are
depicted. The distribution of voting in ten thousand local ward
contests is shown in a unique illustration. Some aspects of what the
census can tell us about many people from their ages, sexes,
occupations, activities and qualifications is revealed over a large set of
very small areas. How people get to work, and the structure of the
towns and cities in which they live, is examined. Migration is studied
in several ways. The changing patterns of migration from birthplace
are shown, and the streams of movement that cut across the country
are drawn in unprecedented detail. House price change is visualized
across several years and thousands of places. New techniques are
developed to show the structure of local housing markets. Through
other methods, the changes in this country’s industrial structure are
seen as they have affected people in actual communities. The spatial
and social manoeuvering of political allegiances is viewed from
several angles, over the same period, and the relationships discussed.
Finally, a smaller scale of analysis is considered, looking at what
many images can tell us about the distribution of a disease, viewed
from many different directions in space and time.
These social and political subjects are not arranged in their own,
individual chapters, but run through the dissertation, which itself looks
at methods of visualization, rather than the visualization of subjects.
The work begins with a plea for a more human cartography to depict
the events of our lives. The long history, but recent explosion, of
envisioning information is then introduced. The rationale for this
method of studying people, places and spaces is discussed. The form
of artificial reality we require — area cartograms — are produced.
The central part of the work looks at the honeycomb structure formed
by the spatial patterns of society at single points in time; and how that
alters through transforming the mosaic. The cobweb of flows which is
responsible for most of the changes and stability is then drawn. This
part of the dissertation is illustrated by many case studies. The last
part attempts to show more complex aspects on the surface of social
landscapes. Sculptured symbols allow us to see the relationships
between the wood and the trees of social structure. Finally, a threedimensional volume visualization of geographical and historical social
structures is attempted. The thesis concludes by describing how all
these methods and insights can together create another geography.
Human geography demands that we consider what is happening in
many places at the same time. We do not need to study aspects of the
world out of context. Here, an attempt is made to cover much ground
and show numerous relationships. To do this it is necessary to be brief
in detail, to be broad in scope, so the pictures often have to speak for
themselves. Much of what has been shown here has never been
successfully analysed by conventional means. However, this research
does not come out of the blue, but accompanies thousands of papers
written in the last three years describing the academic hope for a
revolution in visualization, the history of which goes back to the first
drawings. The message of visualization is that we should literally look
at what is happening, drawing pictures in preference to writing words,
listing numbers or designing theoretical models. It has only recently
become possible to do this in such quantity and quality of detail. The
prints resulting here are the tools of enquiry, not simple pictures for
embellishment, but the foundation of the thesis. This is a story of
invention and discovery.
This thesis is based on two years of research funded by the Strang Studentship of
Newcastle University. During the course of the research I have been helped by
The inter-library loan staff of the Robinson Library kindly waived their normal
restrictions to meet my countless requests. Judith Houston helped secure the
funding and dealt extremely efficiently with the administrative side of my work
throughout the period. Many of the staff of the Centre for Urban and Regional
Development Studies and the Geography and Planning Departments showed an
interest and encouraged me in my work, including Alan Gillard, Tony Champion,
Peter Taylor, David Sear and James Cornford. Colin Wymer, Simon Raybould and
Mike Coombes helped satisfy my appetite for digital information from census
flows, the National On-line Manpower Information System and Building Society
The researchers associated with the NorthEast Regional Research Laboratory were
particularly supportive. Zhilin Li allowed me to use a digital terrain model of part
of Scotland. Anna Cross assisted in accessing the Cancer Registry information.
Steve Carver provided records of road, rail and land-use data. Chris Brunsdon who
advised on the analysis of the house price sample. Stan Openshaw supervised the
project, financed much of the equipment, and supplied the local election and 1971
In particular, thanks are due to Martin Charlton, who read this document and spent
many hours helping me amass the vast majority of the information used here, as
well as permitting extensive use of a great deal of expensive equipment. Bruce
Tether spent many days assisting with the editing and collection of the thousands
of election results used, and gave useful criticism and advice. Richard Park read
and commented on the final draft. Ile Ashcroft and Edward Jones, corrected much
of the English, while Stacy Hewitt gave the work a professional proof-reading.
Eric Charlesworth advised on the style at an early stage, as well as providing
geographical advice. Bronwen Dorling meticulously corrected my writing and gave
constant encouragement, as well as originally teaching me to read. David Dorling
helped rearrange many of the ideas presented here, and first taught me to program.
Finally Anna Macdonald spent several weeks referencing small scale maps and
typing in numerous extensive quotations and tables of data. She also had to put up
with my obsession to finish the work on time. Nothing is achieved in isolation.
Introduction: Human Cartography
Introduction: Human Cartography
Images are only images. But if they are numerous, repeated, identical, they
cannot all be wrong. They show us that in a varied universe, forms and
performances can be similar: there are towns, routes, states, patterns ...
which in spite of everything resemble each other.
[Braudel F., 1979, p.133]
This dissertation presents the thesis that the study of society can be
enlightened through the visualization of social structure. Spatial social
patterns provide the most arresting pictures of the underlying order
and workings of the system, but other facets of the process can also be
transformed into images to illuminate their organization. Visualization
in social science throws light into a dark world of specialisms and
obscurity, showing at an instant how all is connected and everywhere
is different. Most importantly we can begin to see how the structure is
changing what was, and what could be.
The antecedents of this work lie most firmly in human geography and
cartography while being strongly influenced by writings in, and the
combinations of, many other disciplines (Arnheim R. 1976, Muehrcke P.C.
1978, 1981, Bertin J. 1983b, Szegö J. 1984, 1987, Anderson J.M. 1988, Cuff D.J. 1989).
There are contributions from studies in computer and statistical
graphics, graphic design and art, mathematical abstraction (Print I)
and political science. Current thinking in the study of history and
sociology guides much of the writing. Above all, this dissertation is
concerned with designing new ways of seeing the social world we live
in. Before doing that, it is necessary to explain why the accepted
geographical techniques are being discarded by the visual
methodology proposed here. In particular, the conventional use of
Introduction: Human Cartography
maps of physical geography, to show the spatial structure of society, is
Maps were designed to explore new territories and fight over old ones.
They show where oceans lie and rivers run. Their projections are
calculated to aid navigation by compass or depict the quantity of land
under crops (Print II). They are a flat representation of part of the
surface of the globe; they show things which often cannot be seen.
How can we see social structure, as the map opens up land to the
eye1? How can we begin to see the patterns of society, which, from
being part of it we know are there, but have never seen?
Maps were not designed to show the spatial distributions of people,
although the single spatial distribution of people upon the surface of
the globe, at one instance in time, can be shown on them. They cannot
illustrate the simplest human geography of population. People are but
points on the map, clustered into collections of points called homes,
into groups of points known as villages or cities. Communities of
people are not like fields of crops. The paths through space which they
follow are not long wide rivers of water, and yet, to see anything on
maps of people they must be shown as such.
Conventional maps cannot show how many people live in small areas,
instead they show how little land supports so many people. They
cannot show who the people are, what they do, where they go. They
show no temporal distribution, they do not need to — how quickly do
rivers move or mountains shrink on a human timescale? They will not
show the distributions of people changing — international migration,
moving house, or just going to work. They cannot portray the
1 The advantage of maps is simple — they provide context:
Maps frown upon the isolation of single items. They preserve
the continuity of the real world. They show things in their
surroundings and therefore call for more active discernment
on the part of the user, who is offered more than he came for;
but the user is also being taught how to look at things
intelligently. One aspect of looking at things intelligently is to
look at them in context. [Arnheim R. 1976 p.5]
2 [a] The search for a definition of "maps" never ceases:
The current definition of cartography is inadequate largely
because it does not define clearly the focus of the subject,
namely maps. The description of maps is circular — "maps
may be regarded as including all types of maps, charts,
sections ...". This implies two types of maps, namely a
subclass of specific forms, called maps, and a superclass of
generic forms also called maps. The subclass of maps is
defined as a "representation, normally to scale and on a flat
Introduction: Human Cartography
distribution of the wealthy or the poor; on the map, at almost any
scale, they live in much the same square inch of paper. Nor will they
show where and when people had certain jobs, certain power, voted,
were out of work, lived and died. What, after all, is a map2 (Hsu M.L.
1979, Brannon G. 1989, Phillips R.J. 1989)?
Pictures can make ideas plausible, paper beautiful, millions of
numbers meaningful. They have intrigued many, as maps and charts
of rivers and mountains, to the point of being the pretext for their
studying geography. Here traditional maps are the inspiration, but not
the foundation, for the generation of new graphics to form pictures of
people, with their rivers of roads down which they flow, and
mountains of cities up which they climb. The theory of how the
patterns, movement and evolution of the lives of millions can be
transformed to be represented visually, is presented here3.
We want to make sense of the reality of thousands of people
simultaneously threading their way through life (Print III). What are
they doing and why are they doing it? How can we see into every
home, know what everyone does? We can't, but we can guess and we
have some clues. We can guess from what, introspectively, we know
from being part of society. We amass clues when people are counted.
There has been an obsession for counting people since recording
medium, of a selection of material or abstract features on, or
in relation to, the surface of the earth or of a celestial body"
(ICA [International Cartographic Association], 1973, p.7).
This second definition makes it clear that the subclass differs
from its generic class in some ways. But, the two definitions
taken together do not identify the common properties shared
by all maps, which set them apart from artefacts which are not
maps. [Visvalingam 1989 p.26]
[b] The most important aspect of definition concerns
For the ICA, oblivious to the contradiction inherent in its own
definition, the end 'product' or cartographic process (the map)
is to be 'visual, digital, or tactile'. Yet how can numbers, the
constituents of what has been called, appropriately enough,
the 'invisible map' be described as a map before they have
been processed into an image (the visual map)? In following
the politics of expediency rather than linguistic logic, and
anxious to ward off (in the words of one President of the ICA)
the threat of 'rapid submergence' by the new GIS-based
technology, the ICA has managed to shoot itself in the foot. It
has given the non-map parity with the map! [Harley J.B. 1990
[c] An old definition is surprisingly apt:
One of the definitions of the word "map" that appears in the
Oxford Dictionary dates from a source of 1586, where it was
used to describe "a circumstantial account of a state of things
("circumstantial" is defined as "full of circumstances, details
or minutiae"): not a bad objective 400 years later! [Bickmore
D.P. 1975 p.328]
3 The term and philosophy of visualization did not appear
The medium of graphics has long been used to create twodimensional representation of spatial phenomena for the
primary purpose of visualization and, for many, this has also
been the essence of "cartography". [Muehrcke P. 1972 p.27]
Introduction: Human Cartography
became possible. Every ten years, in many countries, hundreds of
thousands of people count people (the census). Increasingly our
actions are being recorded; we are each noted now several times a
day, from the heat we register on satellite images, to almost every
transaction and phone call we make or unit of electricity we consume.
The question this thesis addresses is how can the part of this huge
disparate collection of clues that is available to us be built up to form
an at least partial picture of the patterns we imagine exist. The answer
is, as it has often before been, in the form of pictures.
The conventional statistical treatments of numerical information about
people averages them, agglomerates them and destroys the detail that
is of interest4. They take a million numbers and return half a dozen.
These techniques were conceived when little better could be done.
Now it is possible to show you a million bits of information at a
glance that would be challenging to describe in a thousand words
(Print IV). Our minds are the most powerful tools we have to address
these problems. The difficulty comes in trying to address these
problems to our minds.
Orthodox cartographic methodology has been translated onto the
computer screen (Bickmore D.P. 1975, Hagen C.B. 1982, Taylor D.R.F. 1985, Jupe D.
1987, Goodchild M.F. 1988b, Visvalingham M. 1989, Muller J.C. 1989). The name has
4 It is the great wealth of pattern and variation that is of
interest in many of the pictures drawn in this dissertation:
The dismissal of geographical diversity as merely 'noise' or
'residuals' is a betrayal of what geography is. [Taylor P.J. 1991
5 [a] The cartographic basis of physical geography dates
from a time when land was all important and people had few
Traditional cartography is seen as an optimal response to a
highly constrained technology based largely on pen and paper.
Although many of the conventions of manual cartography
appear to be intelligent choices, they have nevertheless been
made in an extremely restricted environment which imposes a
limited view of reality. Early digital technology did little to
broaden the constraints, and led cartography, map analysis and
spatial analysis in different directions. More recent hardware
and the results of intensive research have produced a digital
cartography which can successfully emulate its analogue
parent. However, its true potential lies in less conventional
methods of analysis and display and in the degree to which it
can escape its traditional constraints. [Goodchild M.F. 1988
[b] Putting the argument less gracefully:
In physical geography, only that which has an effect on
mankind is studied. Now that men are much less dependent on
the countryside than on cities, why have geographers not
followed mankind? Why have geographers left their minds
back on the farm? [Bunge W. 1975 p.177]
[c] New computer systems often fail practically as well as
There seems to be an inverse law where, as the sophistication
of GIS software grows, the attention to basic principles of
graphic design lessens. The emphasis is on getting something
on the screen quickly rather than getting something on the
Introduction: Human Cartography
changed to geographic information systems, but the fundamental basis
of physical geography has remained5. Thematic maps drastically
distort the reality they purport to contain, at worse reversing the
patterns that exist. People who study people, who are interested in
societies, politics, history, economics and increasingly even human
geography, do not use these maps. A topographic map base allows, at
most, the depiction of human land use. People have created maps
based on human geography in the past, but only with the advent of
sophisticated computer graphics has it become possible to do this on
an easily replicable basis.
This thesis is presented as part of the academic revolution known as
visualization, and parallels are drawn with the wider world of
computer graphics. Therefore the basics of what can physically be
seen have to be introduced. How these images are created has to be
explained — from the theoretical to the practical problems. Most
importantly I address the problem of how time and space can be
transformed to represent clearly the patterns within them, on paper, or
That transformation is essential for representation is a most difficult
screen that is meaningful. [Medyckyj-Scott D. 1991 p.21]
6 [a] The geographical features most of us recognise are
not physical — we do not live near mountains:
Base data is so traditional that it invites a critical review.
Consider the use of rivers on base maps. With the invention of
bridges to cross them and railroads to compete with
transportation on them, it could be argued that rivers have
become unimportant enough to be eliminated from the map.
They might be replaced by major railroad lines. In general, the
traditional base map data is especially unsatisfactory to human
geographers. Terrain features might be profitably dropped in
favor of a surface of population density. The "continents" of
population clusters on the Eastern shores of the United States,
Western Europe, China and elsewhere are many times more
important to the economic geographer than the distinction
between land and water traditionally shown and memorized.
Major cities are more important "islands" for many purposes
than the atolls of the Pacific. It is probably true that of all the
degrees of latitude and longitude shown on the map, only the
equator and the poles are on the mental map and, therefore,
the other degrees might be dropped as superfluous. Much of
what has become traditional base map material might have
been selected for no better reason than the ease with which the
material could be gathered by early explorers. It is much
easier to plot the continental outlines, rivers and mountain
peaks than to obtain a census of population or an accurate map
of arable land. [Bunge W. 1966 pp.45-46]
[b] A more human-based geography is being called for:
The inspiration may come not only from the field of
geography / cartography but also from different fields of
artistic endeavour, and lead to the design of maps of human
activities which are much more vital than the thematic maps
of today. Paradoxically, developments in computer technology
may lead to the creation of maps which, when it comes to
spontaneity and liveliness, have more in common with the
popularly-admired and beloved, hand-drawn maps of the
middle-ages and the renaissance than with strict, formalized
cartography of the modern day.
However, certain conditions must be fulfilled for this to
happen. Suitable cartographic data must be made available,
and computers must be adapted to user needs in such a way
that the technology does not impose itself between the user
and his future map. An additional precondition is a revived
interest in working with spatial / geographical problems, and a
renewal of the skills involved in solving such problems by
graphic means as well as in presenting these solutions in a
If these requirements are fulfilled — and the geographer /
cartographer must assume a great deal of responsibility for
this — a new era will be initiated for human cartography.
Introduction: Human Cartography
argument to accept, for it completely alters the images produced and
hopefully the emphasis of the viewer to places, and, more importantly,
the relationship between places and times — the metric. The argument
for transforming to population space, distributions which exist only in
that space, has been made repeatedly over many decades in human
geography. It is simply reiterated in stronger terms here, the new
images being traditionally referred to as cartograms. Put simply,
people no longer exist on paper as points, but as areas6, so can now be
legitimately drawn as fields, their paths as rivers (Print V) perhaps
running through a landscape of accessibility covered with the
vegetation of some aspect of social structure.
This thesis draws on those patterns of people that are familiar to this
writer and the envisaged reader. Britain in the 1970s and 80s is all that
I have known in any detail, and only a very small part of that. The
clues given by the official sources consist mostly of the absolute
numbers, age and sex of people across the country. Then, every ten
years the combinations of their answers to a few questions at the
census are provided, where they were born, what job they do or did,
where they did it, where they moved (Print VI) and so on. But there
are other forms of information that can be drawn on, and, as one claim
of visualization is the ability to handle large quantities of loosely
related data coherently, other sources and surveys are called upon.
[Szegö J. 1987 p.231]
7 [a] There are many sources of digital information about
people in Britain:
The only nation-wide count of the population in Britain occurs
at census year; the last two censuses were held in 1971 and
1981. With no 1976 or 1986 mid-term censuses, this
information is currently produced only once every ten years.
However, during the inter-censal years there are a number of
other sources which can provide information on the changing
socioeconomic, demographic and manpower characteristics of
the population at the local scale ... [McKee C. 1989 p.1]
[b] Pre-eminent in all these data sets is the decennial
Some information on other characteristics of the population
such as house-hold structure, employment status, ethnic
composition and housing situation can be gleaned from the
annual General Household and Labour Force surveys, but the
problem of small sample size virtually rules out their use at
scales below the Standard Region. As a result, the Population
Census is not just the best, but in practice the only, source of
reliable data on a reasonably wide range of demographic and
socio-economic characteristics at sub-regional scale.
Moreover, it has the advantage of providing data down to the
level of the individual enumeration district covering roughly
500 inhabitants, which, even if too small for certain purposes,
can be treated as a building block for areas specially defined
by the user (Rhind, 1983). [Champion A. G. 1989 p.113]
[c] National and local election results also provide
In many ways elections are a positivist's dream. Millions of
people go through the process of voting in numerous countries
every year and these decisions are put together and published
by areal units ready for analysis by social scientists. [Taylor
P.J. 1978 p.153]
Introduction: Human Cartography
How people voted in the local and national elections of the decades,
national surveys of workplaces which were conducted in several
years, the health service records of migration, building societies' lists
of house sales, and information on the infrastructure of roads, railways
and settlements for example, are all digitally available7. What is
sought here is the means of putting these numbers together, as a
collection of images forming one picture of one place during a short,
twenty year or so period of time.
The most simple of spatial distributions to envisage are those captured
at single instances of time, and so it is these with which the examples
of the visualization of spatial distributions in this dissertation begin.
Much of the static spatial social structure is already known intuitively
to social scientists, if not in such great detail and with all places shown
in immediate relation to each other. The degree of complexity and
interdependence shown by the images in this work may also be new to
many. The dissertation then moves on to show changes in the
population over time in a single picture (Print XVII). Much of what
this shows about Britain will be unexpected, as it is only through the
methods employed here that such things can be seen. The way people
move about, day to day, and year to year, is visualized as streams
flowing through space. It must always be remembered that I am not
concerned with two hundred, or a few thousand people, but the
activities of as many as fifty million. The computer is used to handle
these vast numbers, not to produce more numbers, but pictures —
black and white, coloured, and, when required, moving.
Finally I can begin to produce images to depict the little that is known
about large numbers of people, which are totally different from
anything we would recognise in current practice. A notional surface is
proposed where the distance between points is equal to how long it
would take to travel between them, upon which we can then drape
other distributions. It may soon be possible to create true volumes of
Introduction: Human Cartography
pattern and colour to depict the entire evolution of a single
phenomenon, for example unemployment at every place, every month.
The alternative is to cut through this distribution, collapsing all of
space to one point, to draw graphs over time, or all of time to a point,
to show a simple spatial pattern. Inevitably we ask, can we now
combine these disparate images and compare the evolution of one
thing with the flows of another and the distribution of yet others,
without collapsing reality into dimensions which cannot contain its
Presented here is a methodology for studying relatively data rich
spatio-temporal distributions and their interrelations. This goes
beyond the accepted format of book chapters (containing a few tables,
perhaps a graph, or a coarse thematic map) on each of a small number
of topics, with an overview chapter implying that everything is related
but that it's all very complicated. If it is complicated it is interesting —
so let's look at it, rather than repeatedly explaining away the simplest
points, tabulating and sorting the basic rates, or drawing yet more
examples of inappropriate poor quality choropleth maps (by computer
Images of recent British history are being created here which allow
[d] We use whatever information is accessible:
In this book, votes receive rather more emphasis than other
activities only because they have become the currency of
political sociology rather than because they are more "special"
or necessarily more legitimate than other activities. [Agnew
J.A. 1987 p.6]
8 [a] The fundamental cartographic questions are:
"What to map?" "How to map?" "What to do with the maps?"
These three questions sum up the main problems connected
with the mapping of population phenomena and statistical data
generally. Each question gives birth to a brood of lesser
questions, the lesser questions to a third generation, and so on.
The outlines of this genealogy will be traced in the present
I. WHAT TO MAP?
The offspring of "What to map? are (1) "What has been
mapped?" (2) "What can be mapped?" and (3) "What should
be mapped?" ... [Wright J.K. (ed.) 1938 p.1]
[b] Yet fewer and fewer people are asking these crucial
Eavesdropping in the conference bar, the cartographer's
chatter is of the virtuoso Macintosh rather than the question of
why and what we map. Are the mechanics of the new
technology so preoccupying that cartographers have lost
interest in the meaning of what they represent? And in its
social consequences? And in the evidence that maps
themselves can be said to embody a social structure? If
material efficiency is allowed to dominate the design and
construction of maps, we can see why the ethical issues tend
to pass unnoticed. The technology of Geographic Information
Systems (GIS) becomes the message, not just the new form or
medium of our knowledge. [Harley J.B. 1990 p.7]
[c] Questions can often be more important than answers:
It is surprising to learn that such a seemingly perverse world
view is embraced by modern physicists. In the words of John
Wheeler, one of the grand old men of physics, "No elementary
phenomenon is a phenomenon until it is an observed
phenomenon." By this, Wheeler means that the rise of
quantum mechanics has demolished the view that the universe
sits "out there" while we sit back and observe it. The kinds of
questions one asks — and the order one asks them in — has a
Introduction: Human Cartography
new questions to be asked, show different distributions to be
explained, the distributions that many social scientists know are there,
but which traditional cartography fails to depict, and hence to
explore8. There are also glaring patterns to be seen in the well trodden
census tables and government figures which have been ignored, before
we even begin to look for the more subtle or complex and detailed
Visualization can be claimed to solve many of the fundamental
problems identified in studying spatial social distributions (Prints VIII
& IX). The fact that the way you subdivide the space and time you
choose to study can drastically alter the overall impression of your
results, suggests that there are a variety of different views to be
gained, and we should choose those which we wish to believe, in the
light of all possibilities. Here it is argued that previous numerical
profound influence on the answer one gets, and on the world
view one builds up. [Rucker R. 1984 p.193]
[d] What are we doing this for?:
The analytic power to order data has potential equally for
control or liberation. It is all a matter of questions asked and
interpretations made. [Taylor P.J. 1991 p.30]
9 [a] Many eminent cartographers have called for a change
A second challenge requires a greater effort by cartographers
to escape from the constraints of euclidean space and to
exercise more imagination and originality in producing maps.
Barbara Petchenik (Chapter 3) makes a plea that we "... move
our consideration from the domain of rationality and analysis
to an exploration of the domain of synthetic intuition". The
map is a designed object and in our concern with the
"scientific basis" of cartography in recent years we may have
lost sight of the need for more imaginative design. Here
cartographers may have to learn from graphic arts. An
increasing number of thematic maps are being produced by
graphic artists, not by cartographers.
Part of the reason for this is that cartographers are a fairly
conservative group and are still largely prisoners of euclidean
space. Kishimoto (1980) recently drew attention to this fact.
We are increasingly coming to accept the essential difference
between the thematic map and the topographic map but have
not yet accepted that locational accuracy is not always a basic
requirement of the thematic map. We can more effectively and
imaginatively map other "spaces" and give more emphasis to
map content than to geographic location.
Here again, cartographers should take note of the work of
psychologists like Arnheim (1975) and Norman and
Rumelhart (1975) who argue that what a cartographer would
regard as a "distortion" of the "real" euclidean space may in
fact lead to an increase in map clarity. Arnheim uses the
example of the map of the London underground to show how
deliberate distortion of spatial reality can aid the map user and
Norman and Rumelhart demonstrate that when people are
asked to recreate floor plans their drawings rarely represent
euclidean reality. Mills (1981, p.95) comments:
These studies show that human memory is not geared to
produce accurately spatial layouts, even of places with which
one may be very familiar. Instead, people's maps drawn from
memory often distort the shapes and interconnections between
spaces, making them more straight and symmetrical than they
really are, thereby serving to highlight functional, not physical
If this is true of relationships on maps dealing with euclidean
space then it would be reasonable to assume that it would be
equally if not more true of thematic maps. If the gestalt
psychologists are right then "... the most effective maps may
be those which distort objective realism in order to facilitate
the calculation process" (Mills, 1981, p.95) and "creative
distortion" may be necessary to improve communication.
[Taylor D.R.F. 1983 p.288]
[b] Computer cartography could aid, rather than set back,
this new approach:
Cartography in the information age will centre about a
multifaceted model of geographic reality, the spatial data base.
The challenge facing cartographers will be to devise the
theories, methods, and techniques needed to collect, load,
manage, and transform the data items into useable
information. The new cartographic process will form a
continuum of information flow that can be described in terms
of the various generic functions of a spatial data processor.
Technological advances will provide the potential for
collection of vast quantities of basic spatial data. The
distillation of the data into descriptions of geographic reality
that we can understand will require a conception of the
abstract modelling process used by a human to comprehend
spatial entities. Processes to manipulate the data must bridge
the gap between a user's perception and a computer's
Introduction: Human Cartography
solutions to this problem often encouraged even worse symptoms to
emerge. The philosophy adopted here, is to ask how you amalgamate
individuals rather than subdivide society. A logical unit of analysis
does exist for the study of spacetime in human geography — it is a
human life. As yet we have very little information on single people,
but, at least from the census, the data is given at a resolution whereby,
for national pictures what is produced would hardly appear any
different from pictures drawn with the benefit of such information.
For spatial data with a slightly less fine temporal resolution, what we
have can appear as the full picture would, but somewhat blurred. As
long as methods which depend critically on the spatial and temporal
units (or units which would distort any method) are not adopted, such
problems may well be circumvented9.
Social science does need maps; but the maps that are currently drawn
in its name, apart from often being bad examples of physical
geography's cartography, are bad social science. They make
concentrations appear where they are not, and dissolve existing
patterns. They rarely portray anything but the most simple of spatial
distributions, certainly not spacetime evolution, or the interrelation of
a dozen different influences (Print X). Here some of the particular
solutions to mapping that social science requires are given. It is hoped
that while a new methodology is being explained an alternative picture
of Britain will develop through the subjects covered.
representation of spatial reality. Automated cartography will
expand from its robot draftsman roots to a spatial information
system using artificial intelligence techniques to allow the
cartographer not only to produce cartographic products but
also to convey the user-designed view of geographic reality.
[Guptill S.C. & Starr L.E. 1984 p.14]
[c] What ever we do, we must always keep the basic reason
we draw maps in mind:
If the student already carries in his mind's eye the image of a
base map showing the boundaries of the administrative units
by which statistics are tabulated, he may derive from a table of
statistics a hazy idea of the form of a distribution. If no such
picture is present in his mind he can gain no such concept
whatever without the aid of a map. How many of us could
picture the distribution of population in our own state by
studying the census tables alone? Hence statistical maps are
tools for the discovery of new truth. [Wright J.K. (ed.) 1938
Chapter 1: Envisioning Information
Chapter 1: Envisioning Information
We must create a new language, consider a transitory state of new illusions
and layers of validity and accept the possibility that there may be no
language to describe ultimate reality, beyond the language of visions.
[Denes A. 1979 p.3]
1.1 Visual Thinking
Envisioning means bringing into the condition of vision, making
visible, to enable visualization. It is what this thesis practises. Here the
theory behind it is presented. Envisioning is about giving information
to people who can see10. I argue that there are dramatic potential
advantages in using visual images to allow people to unravel the
spatial patterns in complex social structures (Muehrcke P.C. 1969, Arnheim R.
1970, Bertin J. 1981, 1983a, Marr D.
[c] The ideas visualization are easily applied to mapping:
10 [a] The value of visualization was also appreciated in
Often we must deal with conditions where no known
equations will connect our experimental results and where a
mere tabulation of figures will not yield the desired
information without much tedious study. The well recognized
superiority of any graphical representation over an equation or
table in conveying a clear impression to the mind of the way
in which a set of variables is related will often in itself be a
sufficient justification for the use of this type of chart. [Peddle
J.B. 1910 p.98]
[b] Visualization is a way of doing research, not just a
technique for presenting results:
In conclusion, visualization should not be viewed as the end
result of a process of scientific analysis, but rather as the
process itself. More than simply the application of techniques
for displaying data, visualization can be used as a paradigm
for exploring regions of untapped reservoirs of knowledge.
The "Knowledge Navigator" discussed by Apple's John
Sculley in his book Odyssey, is, in some sense, the perfect
model for the visualization process. Jim Blinn has used this
process for over a decade in attempting to simulate planetary
exploration by modelling Voyager's journey through the solar
system. Visualization is not new, but its awareness by the
general scientific community is. [Wolff R.S. 1988 p.35]
Scientists confronted with conceptually difficult processes plot
numbers on graphs to "see" what they mean, often under the
assumption that even bad graphs may provide more meaning
than tidy lists of numbers. Normally we need all the insight
we can get, and graphics are closely associated with the
intuition that lies behind so much creative inquiry. The
computer business increasingly uses pictorial output. Graphics
are used in basic research in engineering, mathematics,
physics, and other fields as a means of visualizing complex
formulas and models. The map, as a graphic form of symbolic
representation, also serves the primary function of
visualization in scientific research (Figure 30).
It appears that maps (or graphics) are not designed, intended,
or well suited for precision work. One should not expect
detailed statistics from mapping. The impact of the map is
more often of greater importance than the information. Maps
serve well the need for a general picture of the nature of a
distribution or the relationships between several distributions,
at least when the patterns are not too large. [Muehrcke P. 1972
[d] Most importantly, visualization guides and inspires us
to see new questions to ask rather than merely repeat old
This elusiveness is not so much a particularity of perception as
it is characteristic of cognition in general. The privilege of
observing everything in relation raises understanding to higher
levels of complexity and validity, but it exposes the observer
at the same time to the infinity of possible connections. It
charges him with the task of distinguishing the pertinent
relations from the impertinent ones and of warily watching the
Chapter 1: Envisioning Information
1982, Tufte E.R. 1990).
Although I have used computers a great deal in this work, I am not
going to concentrate on the mechanics of getting information into the
machine, but how you get it out to people (Prints XI & XII). To
communicate with people you must involve their senses of sight or
hearing, the former transmitting far more information than the latter.
Language, along with music, the most sophisticated use of hearing, is
an excellent means of conveying ideas and thoughts, but cannot
present a large amount of information in a structured form at speed11.
When you look out of the window you can see a great deal in an
instant. The mind has an extremely powerful system for processing
imagery which can instantly analyse a pattern of colours, of light and
shade, and know that these are trees, houses or people out there. How
long would it take to describe all that you can see in words? Yet we
still have to argue, that in the study of societies, there are many things
which cannot be eloquently described in words or succinctly captured
This very thesis is only held together by its text. We have come a long
way with our little symbols, which, after all, exist only because they
effects things have upon each other. [Arnheim R. 1970 p.62]
11 [a] To put the argument somewhat more technically:
Visual displays of information encourage a diversity of
individual viewer styles and rates of editing, personalizing,
reasoning, and understanding. Unlike speech, visual displays
are simultaneously a wideband and a perceiver-controllable
channel. [Tufte E.R. 1990 p.31]
[b] Why does our visual system work so well?:
Human visual perception is performed by the most complex
structure of the known universe, the visual cortex, that
contains at least 1010 neurons, where each neuron in average
contains 104 synapses (gates). This enigmatic processing
network can perform prodigious feats when properly coupled
to the visual stimuli. [Papathomas T.V. & Julesz B. 1988
[c] And how does it operate so quickly?:
Humans can recognize unexpected objects in around 100
neuron-firing times. [Plantinga W.H. 1988 p.56]
[d] Our vision has evolved over a long time to become this
Average human beings can be beaten at arithmetic by a one
operation per second machine, in logic problems by 100
operations per second, at chess by 10,000 operations per
second, in some narrow "expert systems" areas by a million
operations. Robotic performances can not yet provide this
same standard of comparison, but a calculation based on
retinal processes and their computer visual equivalents
suggests that a billion (109) operations per second are required
to do the job of the retina, and 10 trillion (1013) to match the
bulk of the human brain.
Truly expert human performance may depend on mapping a
problem into structures originally constructed for perceptual
and motor tasks — so it can be internally visualized, felt,
heard or perhaps smelled and tasted. Such transformations
give the trillion-operation-per-second engine a purchase on
the problem. The same perceptual-motor structures may also
be the seat of "common sense," since they probably contain a
powerful model of the world — developed to solve the
merciless life and death problems of rapidly jumping to the
right conclusion from the slightest sensory clues. [Moravec H.