Wonder, Sorcery, and Technology: Contribute to the History of Medieval Robotics - History of Computing: Learning from the Past - page 16

Wonder, Sorcery, and Technology: Contribute to the
History of Medieval Robotics

Nadia Ambrosetti

Dipartimento di Informatica e Comunicazione, Università degli Studi di Milano
Via Comelico 39/41, 20135 Milano, Italy
[e-mail]

Abstract. The paper considers some Medieval sources about imagined or actu-
ally studied automata, to make a contribution to the reconstruction of the
cultural landscape of a period that, from the technological point of view, is
commonly regarded as less interesting than others. It will be shown that the idea
of an automatic device or system, capable of performing not necessarily simple
tasks, of measuring its own state and of taking action based on it, was well es-
tablished in the Medieval mind, even though sometimes connected with magic.

Keywords: automata, design, sorcery, science, technology, feed-back control,
history, magic, robot, robotics.

1 Introduction

The Greek adjective , coming from the adjectives

(self) and

(having in mind, acting), was at first used to refer to any event, that happened sponta-
neously, without external intervention; later its use was extended to those mechanical
devices, which perform, after a user's input, a finite number of default actions, typi-
cally, but not necessarily in a periodic sequence. Such automata were, during the Hel-
lenism, also equipped with mechanisms for controlling their state and were so capable
of taking action in dependence on the state itself (a first and essential mechanism for
feedback). The purpose they were built for, was essentially playful: they were made to
arouse the spectators' wonder ( ) and therefore their admiration not only for the
engineer's skills, but also for the monarch, who had sponsored his designs and works.
Often, these designers managed to surprise their audience through the implementation
of devices activated by an input that doesn't appear to involve the produced effect: the
typical example is the mechanism that opens the doors of a temple after the lighting of
a ritual brazier. We rarely find examples of devices which also can have a practical use
(such as a purifying water dispenser, or a pump to extinguish fires).
The most important source for this study are the works by Hero of Alexandria (1 st
century AD): (Pneumatics) and (Automata build-
ing); these works came to us almost complete and they let us understand much of
ancient engineering applied to automata. This fortunate tradition demonstrates that
such works passed from Alexandria into the Romans' hands at first, then to the By-
zantines and Arabs; during the Dark and Middle Ages they were read, understood,