Simulation, Representation, and Cartography: Compiling a Virtual Atlas Johannes Lenhard Bielefeld University Simulation modeling resembles map-making in an important way: Both aim at constructing devices for orientation and for intervention. The reference to reality or the terrain, however, is far from straightforward. Rather, the result of simulation modeling can be conceived of as a virtual atlas – an object different from a traditional atlas. It consists of a huge compilation of local maps that do not match up to a general overview. Only in a computational setting such an atlas can be used as an orientation device. 1. Introduction It is a commonplace that “the map is not the territory.” The phrase goes back to Alfred Korzybski (1931), while the insight—formulated by insisting on an apparent triviality—is surely older and has received poetical expressions from Lewis Carroll and Jorge Luis Borges among others. The difference between map and territory is a difference of categories and is at the base of the representation relation. Hence maps play a prominent role in the dis- course about representation which takes place in a number of disciplines and from different perspectives. Three of them are of special interest for the present paper. One influential view has been put forward by historian of art Ernst Gombrich in his classical lecture on “Mirror and Map” (1975) where he states that the mirror opens up a sophisticated play of representation, whereas the map is less interesting because it (just) presents a well-defined scientific I would like to thank Anne Marcovich, Terry Shinn, the audiences of the conferences “Imaging NanoSpace” and “Models and Simulations 5,” and also two anonymous reviewers for their helpful comments. Perspectives on Science 2015, vol. 23, no. 4 ©2015 by The Massachusetts Institute of Technology doi:10.1162/POSC_a_00180 386 Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/POSC_a_00180 by guest on 28 September 2021 Perspectives on Science 387 artifact, a practical tool, constructed in precise and systematic ways.1 The second viewpoint has been articulated in the history of cartography. It dismisses the above description of maps as an overly rationalistic and his- torically inappropriate model. To think maps would be different from art or painting because they create a straightforward similitude to reality would be to fall prey to an “illusion of map-making”—states historian of cartog- raphy Brain Harley (2001, p. 154). The philosophy of science contributes a third perspective: It has discovered maps as an interesting topic because they are related both to objectivity and conventions, hence can serve as a resource to scrutinize the ways scientific knowledge is organized. The present paper will bring together all three perspectives on science and map-making, and it will utilize them to investigate and probe a claim about simulation modeling and its relationship to mapping. The main claim holds that simulation modeling resembles map-making in an im- portant way and can be compared to compiling a virtual atlas. However, this virtual atlas is different from a regular one. While the latter is comprised of a number of local maps that together cover a certain territory, its virtual counterpart resembles the compilation of particular itineraries. The argu- mentation will proceed in the following way. Section two will briefly introduce the discussion of map-making in the philosophy of science. The standard account treats maps as a paradigm for representation that is based on an isomorphic relationship. Such an account tends to see maps as generic objects of little particular philosophical inter- est. For more than a decade, the topic of maps and map-making is re- ceiving increasing attention, connected to a practice turn and to a turn from theories to models. The analysis of map-making has enriched the con- ceptual repertoire one can use to think and debate about representation. The fact that there are several maps of the same territory that are useful for different purposes has inspired the debate about the (non)uniqueness of knowledge representations. In particular, it will be discussed how the pluralist stance of Helen Longino (2002) and the realist position of Philip Kitcher (2001) combine. A second and especially important aspect con- cerns the global versus local character of maps and how maps of different scales are systematically related. This relationship will be helpful to ana- lyze simulation modeling, namely my pointing out the difference between (general) maps and a compilation of particular itineraries. Section three will introduce nanoscale research as a field where map- making and simulation modeling both play important roles. Two types of images will be distinguished. The first type is produced by scanning 1. Various scholars have embraced similar views, cf. Arnheim 1986; Eco 1976; Goodman 1968. Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/POSC_a_00180 by guest on 28 September 2021 388 Simulation, Representation, and Cartography tunnel microscopy; it is a popular one and displays molecular landscapes that suggest space metaphors for nano of great rhetorical force. The second type is images produced by simulation models that from the outset do not appear to be map-like. A case from tribology, i.e. the study of friction, where molecular dynamics simulations are employed, will be introduced and discussed for illustration. It will be argued that the first type of image appears map-like by a rather superficial analogy, while the second type in fact exhibits an inter- esting functional analogy between simulation modeling and map-making. The philosophical account of mapping considerably profits when com- plemented by considerations and material from the history of cartography. This will be undertaken in the fourth section. Historians of cartography have articulated fundamental criticisms of the “ideology of map-making” that takes maps for objective and neutral representations. Rather, they conceive of map-making as an activity that is carried out in a historical and political context. To them, maps are constructed as orientation devices and to provide options for interventions in very particular contexts. The “Great Survey” of India that the British Empire conducted (Edney 1997) will serve as source for illustration. In effect, the material will vindicate the connection between map-making and modeling. Section five will pull the threads together. The philosophical and historical discussion of mapping will be utilized to analyze simulation modeling. The notions of prediction, negotiation, and locality will play a central role. It will be argued that simulation modeling can indeed be compared to map- making: both activities create devices for orientation and for intervention. The result of simulation modeling can be conceived of as a virtual atlas— an object that differs from a regular atlas in important ways. It consists of a huge compilation of particular itineraries that do not match up with a gen- eral overview; rather they lack the relation to something like an ordinance survey map that would integrate the local maps. Only in a computational setting, it is claimed, can such an atlas be used as an orientation device. 2. Representation and the Map-Making Paradigm Maps serve as an interesting issue for philosophy of science because they are examples of representations that are systematic and successful (in a sense to be specified) and therefore can serve as a prima facie point of reference for investigating scientific knowledge in general. However, a common view in epistemology does demand strict measures of objectivity for knowledge. If maps should be a point of reference, doesn’t that demand highest stan- dards of objectivity for maps and map-making, too? Some practice-oriented philosophers of science have turned around the perspective and asked what the investigation of map-making can tell about scientific epistemology. Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/POSC_a_00180 by guest on 28 September 2021 Perspectives on Science 389 Scholars like Ron Giere, Philip Kitcher, and Helen Longino – leaving aside relevant differences between them – all invoke the example of map-making when they critically debate central features of knowledge and representation. The common point of departure of these authors is to explain how scien- tific knowledge deserves the character of a success term without relying on a rigid truth standard that hardly fits any aspect of scientific practice. At the same time, knowledge shall keep its truth standard. This attempt has led them to consider maps as a paradigm case: map-making can produce suc- cessful devices in a systematic way. Three aspects will be addressed in the following: instrumental character, pluralism, and systematic connectivity. Stephen Toulmin is an important voice in appreciating the significance of maps. He devotes chapter four of his introduction to philosophy of science (1960) to “theories and maps.” Toulmin points out that neither theories nor maps have a deductive connection to facts. Maps serve as a paradigm case that should inform our thinking about laws: they are not strictly derived from the terrain, though one can read off propositions about geographical facts. Thus, for Toulmin, maps and natural laws have in common their character as instruments: both are orientation devices—in a terrain (maps) or in a range of phenomena (laws). The term “orientation” here is not restricted to the spatial sense. Laws can