The Hierarchy of Models in Simulation

Abstract

This paper focuses on the role of the computer in helping to manage mathe-matically unsolvable sets of equations that arise within models in the physical sciences. The study of these models often consists in developing representations of the underlying physics on a computer, and using the techniques of computer simulation in order to learn about the behavior of these systems. I argue that this process of transformation, which involves a hierarchy of models, is also a process of knowledge creation, and it has its own epistemology. Accordingly, I urge philosophers of science to examine more carefully the process of theory articulation, the process by which a general theory is made to conform to a particular application. It is a relatively neglected aspect of scientific practice, but it plays a role that is often as crucial, as complex, and as creative as theorizing and experimenting. Indeed, my conclusion will be that we now need a new philosophy of simulation to complement recent work on the philosophy of experiment.