The Controversial Status of Simulations

It is claimed that simulations maintain an independent status in knowledge production – they combine traits both of experiment and theory. In particular, simulation procedures differ fundamentally from numerical calculations in the strict sense, rather they can be seen as imitations of complex dynamics by a suitable generative mechanism. To argue for this claim results from a case study of climate research are employed. The simulation models of the general circulation of the atmosphere are based on theoretical models (PDEs), but they cannot be derived from the theory. The case study will show that simulation models have to take certain liberties. Namely, the performance on the computer is more important than the model’s derivation and its accuracy of calculation.