Dipole Radiation – Multiple Visual Representations to Assist Learning

The Hertzian Dipole is a standard topic for lectures in physics. It points to the fundamental mechanism that is responsible for electromagnetic radiation. Understanding the Hertzian Dipole is the first step toward understanding toward understanding the physics behind different antenna types, such as half-wave antennas and other types. But it is not easy to discuss the spatial and time-dependent behaviour.

Suitable illustrations and animations showing the formation of electromagnetic waves can help for teaching and learning. Moreover, a combination of multiple graphical representations can bring to light the relationships between different aspects. An HTML5-applet was written, specifically to illustrate dipole radiation. The program "DipoleRadiation" is designed to make aspects of electromagnetic radiation visible that cannot be seen directly.

In an explorative pilot study students were interviewed to find out more about their problems. Furthermore, an eye-tracker study was carried out to identify, what learners focussed on. First findings revealed some gaps in knowledge. Among them are a simple lack of prior knowledge, misunderstanding of models, invisible features, spatial imagination, and the ability to identify important details and abstractions from the superficial.