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History of Computer Art
II.2 Cybernetic Models
In 1946/47 William
Ross Ashby realised a technical system as a model for his theory of
homeostasis (see chap. II.1.5). This system offering a theory´s
test case inspired in the fifties and sixties artists constructing cybernetic
sculptures (see chap. II.3). "Homeostat" is a technical model
demonstrating a system´s limited capabilities to adapt itself to
environmental conditions. The flow of energy in the technical model is
used to demonstrate how the system/environment relation functions in biological
systems, for example to maintain the body heat. Cybernetic scientists
develop theories valid across systems, construct technical models for
them, and compare them with characteristics of creatures: from theory
to machine to creature and back. 1
Ashby, William Ross: Homeostat, 1946-47 (Ashby: Design
Four units being sensitive to disruptions and compensating
them are connected by Ashby to build the system of "Homeostat".
On each unit a magnet controls the deflections of a needle. Placed in
a conductive liquid the needle reacts to the system´s voltage fluctuations.
"Uniselectors" introduce system-internal disturbances by chance-operations.
Controllers ("commutators and potentiometers") on the four units
make the regulation of energy possible. The system reacts to changing
energy flows within its possibilities to execute compensation movements:
The output of one unit becomes the input of the next unit. This results
in a system behaviour keeping the needle stable in the midst of its swinging
possibilities. Ashby designates this self-regulation as "ultrastability".
Ashby, William Ross: Homeostat, circuit diagram (Ashby:
Design 1960, p.102).
In his presentation of the "Homeostat"
in 1952 at the ninth Macy
Conference in New York Ashby was faced with expectations that his
system should have a "memory" 3 to be able
to store previous processes and to use the store to learn not to repeat
them. For the participants of the Macy Conferences was a consequence of
this expectation and the assertion to be able to realize technically the
functions of a concept 4 to ask how the capabilities
of memorizing and learning can be implemented technically.
In 1951 Claude Elwood Shannon presented a system with
memory at the eighth Macy Conference: The "sensing finger" of
the "Maze Solving Machine" 5 memorized previous
paths and returned to them if it moved to a blind end. The way to the
goal became shorter because after failure the search had not to be started
from the beginning, meanwhile Ashby´s "Homeostat" compensated
deviations each time as if it had never before done that in the same situations.
But Shannon could not present a model with the ability to draw conclusions
from elder experiences for new navigation strategies.
Shannon, Claude Elwood: Maze-Solving Machine, plan
(Shannon: Presentation 1951, p.174, figure 8).
In 1948 William Grey Walter constructed his first roboter "Elmer"
finding his path between obstacles by self navigation. To construct the
robot Walter used radio tubes, switching relays, photocells, and little
microphones. Three years later he constructed "CORA" as a robot
memorizing obstacles: In its search for a path "CORA" circumvented
the positions of obstacles or of test persons. A test person could signal
with a whistle to the robot: Don´t move in this not any further
Walter, William Grey: Elmer, 1948.
robot construction was not only sensitive to sounds and touch contacts
but to light, too: It reacted to reflexes of the light mounted on its
covering. A mirror´s reflexes of its own light provoked a dance
because the mechanism to change its direction caused repeated, staggered
motions. 6 The progress from the "Machina Speculatrix"
"Elmer" to the "Machina Docilis" 7
demonstrated "CORA" with its capability to memorize obstacles
and to find itself the path to its garage with electricity supply: "CORA"
is seen as a precursor of "artificial intelligence". 8
Walter, William Grey: Cora, model for demonstrations
on a table, 1951 (constructed by Bunny Warren for the Festival of Britain
in London, Exhibition of Science,
Science Museum, South Kensington, 1951).
In the book "The Living Brain",
published in 1953, Walter compared "an electrical oscillation at
low frequency" of "CORA" with "feedback circuits from
cell-group to cell-group" in the brain. 9 He measured
brain events as electroencephalogram in sequential phases of time. So
it became recognizable if an event was forgotten, memorized, or processed.
In the forties and fifties Shannon, Ashby and Walter developed technical
constructs for cybernetic theories anticipating later developed programs
Wiener designated processes of calculators from the
abacus to the digital computer as "computing". 11
The cybernetic models featured in this chapter present concepts of computing
processes in systems reacting to external events in a state of differentiation
becoming relevant for early artistic projects for computers (see chap.II.3.1,
Dr. Thomas Dreher
with numerous articles on art history since the sixties, a. o. on Concept Art and Intermedia
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1 Ashby: Design 1960, p.98s. on the "homeostat"
as an "analogue computer" for the research of "ultrastable
systems", and Ashby: Variety 1958, chap. The Message of Zero Entropy
on "the homeostatic mechanism" to maintain the body heat. back
2 Ashby: Design 1960, p.98s.,103s.; Pickering: Brain
2010, p.101-106. back
3 Ashby: Homeostasis 1952, p.104/615s.; Bluma: Wiener
2005, p.156s. back
4 Ashby: Homeostasis 1952, S.107f./618
includes the following discussion contribution by Walter Pitts: "At
the very beginning of these meetings, the question was frequently under
discussion of whether a machine could be built which could do a particular
thing, and, of course, the answer, which everybody has realized by now,
is that as long as you definitely specify what you want the machine to
do, you can, in principle, build a machine to do it." back
5 Bluma: Wiener 2005, p.157; Shannon: Presentation 1951.
6 Walter: Brain 1961, p.241: "turn- and- push manoevre".
On "Elmer": Hoggett: Elmer 2009.
On "CORA": Hoggett: CORA 2009; Pickering: Brain 2010, p.64-67;
Walter: Brain 1961, p.118,155ss.,245-250. back
7 Pickering: Brain 2010, p.64; Walter: Brain 1961, p.155ss.,241-244.
8 Holland: Walter 1997.
For Reuben Hoggett there was not only a static object to demonstrate functions
of a machinic brain but a robot, too, with an integration of that machinic
brain (Hoggett: CORA 2009). back
9 Walter: Brain 1961, p.163. back
10 Burnham: Modern Sculpture 1978, p.331,334s.; Pickering:
Brain 2010, p.64ss. back
11 Wiener: Cybernetics 1949, p.20. back
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