2016. Smaller than a Breadbox: Scale and Natural Kinds. ASAP at British Journal for Philosophy of Science

I propose a division of the literature on natural kinds into metaphysical worries about essences, semantic worries about referents, and methodological worries about how classification influences scientific practice. I argue that the latter set of worries should occupy center stage in philosophy-of-science discussions about natural kinds, and I apply this methodological framework to the problem of classifying nanomaterials. I show that classification in nanoscience differs from classification in chemistry because the latter relies heavily on compositional identity, whereas the former must consider additional properties, namely size, shape, and surface chemistry. I use this difference to argue for a scale-dependent theory of classification, and I show that the multi-valued approach to classification in this theory supports the differing goals of different scientific projects.

2016.  (with M. Roco, J. Schummer, P. Weiss, et al.) Nano on ReflectionNature Nanotechology 11 (10), 828–834.

In the past decade, nano has shown definitively that scale constrains scientific activity from the conception and carrying-out of an experiment to the choice of theories, models and simulations used to predict and explain those experimental results. In the decades to come, nano will reshape the structure of scientific knowledge as scientists and philosophers recognize the import of systematically scale-dependent investigations on our conceptual understanding of the material world.

2016. Conceptual Analysis for NanoscienceJournal of Physical Chemistry Letters 7 (10), 1917–1918.

Collaboration between scientists and philosophers of science reveals new domains for conceptual analysis and new research opportunities for both philosophers and scientists. 

2015. Surfaces, Scales, and Synthesis: Scientific Reasoning at the Nanoscale. Dissertation, University of Pittsburgh.

Philosophers interested in scientific methodology have focused largely on physics, biology, and cognitive science. They have paid considerably less attention to sciences such as chemistry and nanoscience, where not only are the subjects distinct, but the very aims differ: chemistry and nanoscience center around synthesis. Methods associated with synthesis do not fit well with description, explanation, and prediction that so dominate aims in philosophers’ paradigm sciences. In order to synthesize a substance or material, scientists need different kinds of information than they need to predict, explain, or describe. Consequently, they need different kinds of models and theories. Specifically, chemists need additional models of how reactions will proceed. In practice, this means chemists must model surface structure and behavior, because reactions occur on the surfaces of materials.

Physics, and by extension much of philosophy of science, ignores the structure and behavior of surfaces, modeling surfaces only as “boundary conditions” with virtually no influence on material behavior. Such boundary conditions are not seen as part of the physical laws that govern material behavior, so little consideration has been given to their roles in improving scientists’ understanding of materials and aiding synthesis. But especially for theories that are used in synthesis, such neglect can lead to catastrophic modeling failures. In fact, as one moves down toward the nanoscale, the very concept of a material surface changes, with the consequence that nanomaterials behave differently than macroscopic materials made up of the same ele- ments. They conduct electricity differently, they appear differently colored, and they can play different roles in chemical reactions. This dissertation develops new philosophical tools to deal with these changes and give an account of theory and model use in the synthetic sciences. Particularly, it addresses the question of how models of materials at the nanoscale fit together with models of those very same materials at scales many orders of magnitude larger. To answer this and related questions, strict attention needs to be paid to the ways boundaries, surfaces, concepts, models, and even laws change as scales change.

2014. "Microstructure without Essentialism: A New Perspective on Chemical Classification." Philosophy of Science 81 (4), 633–653.

Recently, macroscopic accounts of chemical kind individuation have been proposed as alternatives to the microstructural essentialist account advocated by Kripke, Putnam, and others. These accounts argue that individuation of chemical kinds is based on macroscopic criteria such as reactivity or thermodynamics, and they challenge the essentialism that grounds the Kripke-Putnam view. Using a variety of chemical examples, I argue that microstructure grounds these macroscopic accounts, but that this grounding need not imply essentialism. Instead, kinds are individuated on the basis of similarity of reactivity between substances, and microstructure explains similarity of reactivity. 

2012. "Pauling's Defence of Bent Equivalent Bonds: A View of Evolving Explanatory Demands in Modern Chemistry." Annals of Science 69 (1), pp. 69–90.

Linus Pauling played a key role in creating valence-bond theory, one of two competing theories of the chemical bond that appeared in the first half of the 20th century. While the chemical community preferred his theory over molecular-orbital theory for a number of years, valence-bond theory began to fall into disuse during the 1950s. This shift in the chemical community's perception of Pauling's theory motivated Pauling to defend the theory, and he did so in a peculiar way. Rather than publishing a defence of the full theory in leading journals of the day, Pauling published a defence of a particular model of the double bond predicted by the theory in a revised edition of his famous textbook, The Nature of the Chemical Bond. This paper explores that peculiar choice by considering both the circumstances that brought about the defence and the mathematical apparatus Pauling employed, using new discoveries from the Ava Helen and Linus Pauling Papers archive.

2011. Review of The Disappearing Spoon, by Sam KeanSpontaneous Generations 5(1), pp. 100–102.

2009. "The Space Between and the Space Within: On The Definition, Conception, and Function of Space in Leibniz's Late Metaphysics." Think: The West Virginia University Undergraduate Journal of Philosophy 1, pp. 17–31.



2016. With Monika K. Chao. Heard but Misunderstood: Understanding Negative Reactions to Female Vocal Fry

In this paper, we use evidence from sociolinguistics and philosophical frameworks from contemporary speech act theories to analyze the current phenomenon of negative responses to instances of female vocal fry. We show that negative reactions to female fry arise from its apparent violation of the frequency code, and that responses to this violation can be best understood as the hearer interpreting the speaker as producing an echoic, ironic utterance. We argue that the perception of a frequency code violation leads some hearers to believe they have license to dismiss the speaker as mocking a more masculine speaker, rather than saying anything at all.

2015. Multiscale Modeling: Beyond Non-Mereological Relations.

Winsberg's "handshaking" account of inter-model relations is a well-known theory of multiscale modeling in physical systems. Winsberg argues that relations among the component models in a multiscale modeling system are not related mereologically, but rather by empirically determined algorithms. I argue that while the handshaking account does demonstrate the existence of non-mereological relationships among component models, Winsberg does not attend to the different ways in which handshaking algorithms are developed. By overlooking the distinct strategies employed in different handshake models, Winsberg's account fails to capture the central feature of effective multiscale modeling practices, namely, how the dominant behaviors of the modeled systems vary across the different scales, and how this variation constrains the ways modelers can combine component models. Using Winsberg's example of nanoscale crack propagation, I distinguish two modes of handshaking and show how the different modes arise from the scale-dependent physics involved in each component model.

2015. Surface Tension

At the macroscopic scale, surfaces are often ignored as boundary conditions, that is, parts of a material that do not significantly impact the physical or chemical behavior of that material. At the nanoscale, however, the behavior of surfaces dominates the behavior of materials. This scale-dependent change in the role of surfaces leads to a change in what it means to be a surface; this is a form of conceptual instability that Wilson has termed "multi-valuedness." Responding to this multi-valuedness requires a new account of inter-theory and inter-model relations. This account, which I call the model interaction account, is an alternative to traditional views of reductive and emergent relations between theoretical frameworks, and it hinges on the exchange of information across theoretical frameworks through attention to boundary behaviors. I argue that philosophical theories of explanation, prediction, modeling, and design need to attend more closely to the dependence of these activities on boundary conditions. 


2012. Reconsidering Explanation: Lessons from Nanosynthesis. Read for the Philosophy of Science Association 2012 biennial meeting.

Nanosynthesis forces a reevaluation of received views on scientific explanation. I discuss the synthesis of anisotropic metal nanoparticles, a typical nanosynthesis research program, in order to demonstrate the failure of standard philosophical accounts of explanation to capture the dynamics of information exchange in synthetic sciences. I argue that using the language of effective heuristics, coupled with attention to changes in the meanings of concepts across different length scales, is a more promising means of capturing how information is obtained from the study of nanosynthesis systems.