Why We Eat Calories: A Plurality Metaphor of Energy in Scientific Disciplines

In the Next Generation Science Standards, energy is considered a “crosscutting concept” that bridges disciplinary boundaries and unites scientific disciplines. I examine how energy is represented in physics, biology, and chemistry contexts, using the reaction of molecular oxygen with sugar as an exemplar, and argue that disciplines disagree in how they represent the origin of energy that drives this process. In particular, while biology tends to locate energy as initially in the sugar molecule, chemistry locates the energy in molecular oxygen, and physics models energy as in the field between the molecules. That is to say, biology describes us as eating calories, chemistry as inhaling calories, and physics invents an abstract object (the field) as the container for energy. I then show how the conceptualizations made in each discipline stem from core disciplinary commitments, models, and concepts that structure what “counts” as an explanation. This conceptual plurality, then, is essential to disciplinary meaning. While such a pluralistic conceptualization appears to be contrary to scientific epistemology that prioritizes coherence and cognitive models that rely on unitary structures for transfer, I draw on recent research to argue that neither concern is fully founded. Finally, I suggest that building bridges between these contrasting conceptualizations may come later, in response to interdisciplinary questions and frameworks.