Physics students learning about abstract mathematical tools when engaging with �invisible� phenomena

The construction of physics knowledge of necessity entails the combination of a wide range of resources, (e.g. specialized language, graphs, algebra, diagrams, equipment, gesture, etc.). In this study we documented physics students' use of different resources when working with an "invisible" phenomenon;magnetic field. Using a social semiotic framework, we show how appropriate coordination of resources not only enabled students to learn something about the Earth's magnetic field, but also about the use of an abstract mathematical tool; -coordinate systems. Our work leads us to make three suggestions: