Negative Energy: Why Interdisciplinary Physics Requires Multiple Ontologies

Abstract

Abstract. Much recent work in physics education research has focused on ontological metaphors for energy, particularly the substance ontology and its pedagogical affordances. The concept of negative energy problematizes the substance ontology for energy, but in many instructional settings, the specific difficulties around negative energy are outweighed by the general advantages of the substance ontology. However, we claim that our interdisciplinary setting (a physics class that builds deep connections to biology and chemistry) leads to a different set of considerations and conclusions. In a course designed to draw interdisciplinary connections, the centrality of chemical bond energy in biology necessitates foregrounding negative energy from the beginning. We argue that the emphasis on negative energy requires a combination of substance and location ontologies. The location ontology enables energies both "above" and "below" zero. We present preliminary student data that illustrate difficulties in reasoning about negative energy, and the affordances of the location metaphor.

NEXUS/Physics: An interdisciplinary repurposing of physics for biologists

“…For more details, especially some discussions of detailed case studies, see the cited papers. 29,36,37,43,45,55 From our observations we conclude:…”

Student reasoning about electrostatic and gravitational potential energy: An exploratory study with interdisciplinary consequences

“…Few students who cited an equation relating potential energy and distance in their reasoning for the two massive blocks problem included a negative sign with that equation. It has been documented that students struggle with the idea of negative energy [4,15]. Many students may recognize that potential energy should be zero when two objects are infinitely far apart, but then draw incorrect conclusions.…”

“…The topic of energy has recently been receiving increased attention in the physics education research (PER) literature [1][2][3][4][5]. The emphasis on energy has been particularly strong in interdisciplinary education research.…”

Student use of energy concepts from physics in chemistry courses

“…Other research reveals additional difficulties with the concept of potential energy that have potential interdisciplinary consequences. For instance, many students find the idea of negative potential energy to be difficult (Stephanik and Shaffer, 2012;Dreyfus et al, 2013). While frequently avoided when dealing with near-Earth gravitational interactions (such as are typically used to introduce the idea of potential energy in chemistry textbooks), the description of potential energy as a negative function becomes important when distinguishing between the potential energy of a system of attracting objects versus the potential energy of a system of repelling objects -both of which appear in chemistry contexts.…”