Charles Care

Historians of computing will be familiar with analog and digital, technical terms that represent two very separate classes of technology and two distinct genres in the historiography of computing. Around 1950, analog was a major class of machine, and was gradually replaced by digital through a complex technological change. It is evident that the transition from analog to digital can only be explained in terms of the users of the technology: the history of various application areas each tells a different story of analog-digital change.

Analog computers are usually associated with modeling, their major use being the development of models and simulations of physical systems. To understand how this tool became ‘digital’, this paper considers the computer as a modeling machine; a perspective complimentary to the theme of ‘computer as information machine’ dominant in much existing historiography. Instead of analyzing the two technologies separately, both are addressed through the common theme of modeling technology.

Approaching the history of the computer from the perspective of ‘computing as a modeling medium’ highlights how analog computing interrelates with other modeling technologies such as wind tunnels and electrolytic tanks. When used as a modeling technology, the computer becomes the latest example of a tool employed in this experimental tradition. This study explores the evolution of this tradition, relating what is now principally a computing culture to these older empirical (and often lab-based) technologies.

Cutting across traditional technological genres, this approach exposes a continuity between analog and digital applications not usually considered. Rather than portraying analog and digital as separate paradigms in the history of computing, it is shown that the analog-digital shift is really about how users respond to the transfer from one modeling medium to another.

Modeling has become a topic of interest for a number of scholars working within the history of science and technology. Commonly cited works are those of Daniela Bailer-Jones and the collection of articles “Models as Mediators” edited by Mary Morgan and Mary Morrison, all of which approach the topic from a philosophy of science background.  This paper develops the connections between such work and the growing literature on models as technology through exploring the epistemological aspects of models and how they are constructed.

If computers are to be considered modeling machines, then this perspective reflects a use of technology centered on knowledge generation and acquisition rather than information management and retrieval. Using examples drawn from aeronautical engineering, weather prediction, and oil reservoir modeling, this study considers the role of users and how they employ computer technology to generate knowledge through developing and sharing models. Emerging issues are the reliability and trustworthiness of models created in such a transitory medium, and the quality of knowledge delivered.

Computer technology has a plurality of different application cultures, each culture communicating an individual concept of computing and reflecting their individual technical heritage. Unpacking the various ideas of these communities demonstrates the need for multiple historiographical narratives of computers and computing; thus justifying an approach that considers new thematic associations such as modeling.