Artificial intelligence and neural networks - The Computing Universe: A Journey through a Revolution - page 263

13 Artificial intelligence and neural networks

It is not my aim to shock you - if indeed that were
possible in an age of nuclear fission and prospective
interplanetary travel. But the simplest way I can
summarize the situation is to say that there are
now in the world machines that think, that learn
and that create. Moreover, their ability to do these
things is going to increase rapidly until - in a visible
future - the range of problems they can handle will
be coextensive with the range to which the human
mind has been applied.
Herbert Simon and Allen Newell 1

Cybernetics and the Turing Test

One of the major figures at MIT before World War II was the mathemati-
cian Norbert Wiener ( B.13.1 ). In 1918, Wiener had worked at the U.S. Army's
Aberdeen Proving Ground, where the army tested weapons. Wiener calculated
artillery trajectories by hand, the same problem that led to the construction
of the ENIAC nearly thirty years later. After World War II, Wiener used to hold
a series of “supper seminars” at MIT, where scientists and engineers from a
variety of fields would gather to eat dinner and discuss scientific questions.
J. C. R. Licklider usually attended. At some of these seminars, Wiener put for-
ward his vision of the future, arguing that the technologies of the twentieth
century could respond to their environment and modify their actions:

The machines of which we are now speaking are not the dream of the
sensationalist nor the hope of some future time. They already exist as
thermostats, automatic gyrocompass ship-steering systems, self-propelled
missiles - especially such as seek their target - anti-aircraft fire-control
systems, automatically controlled oil-cracking stills, ultra-rapid computing
machines, and the like.… 2

B.13.1. Norbert Wiener's
(1894-1964) name is mainly asso-
ciated with the term cybernetics .
Cybernetics is an interdisciplinary
theory describing how complex
systems regulate themselves using
feedback mechanisms. Wiener was
only eighteen when he earned his
PhD degree in mathematics from
Harvard University. During World
War II, he worked on automatic con-
trol of antiaircraft guns.

All these applications rely on feedback for their ability to learn and adapt. To
see how such environmental feedback works, consider a simple thermostat. A
bimetallic thermostat has a strip made of two metals fastened together that
expand and contract at different rates when the temperature rises and falls. As
a result, the thermostat bends when cold and straightens out when warmed
( Fig. 13.1 ). When the temperature drops low enough, the thermostat bends far
enough to close an electrical circuit that causes the heating to come on. When

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