Models in the Explanations of Physics: The Case of Light

Abstract

Over the centuries, the basic utility of physics explanations has laid a solid base for investigations, explanations and models in other subject areas. As the technology and instrumentation have improved, so the explanations and associated models have become more detailed, more predictive and a better fit to the phenomenon under investigation. In general, one consensus model has emerged which has held sway until some form of Kuhnian paradigm shift has occurred. However, there is one important phenomenon which has yet to develop a single consensus model, the phenomenon of light. This chapter therefore looks at the development of the models used to explain optical behaviour, how opinion has oscillated between the two major theories or explanations and the rather uneasy combination of them in the wave-particle duality explanation. This duality highlights the nature of models in that one is unable to say ‘light is ...’ but must always say ‘in this instance light behaves as if..’ The phenomenon may therefore be a very useful tool in teaching about the nature of models. It could be argued that ‘the case of light’ is an ideal one for an examination of what is meant by a model, how models can be used and when they have been stretched too far. In the final sections of the chapter, the teaching of optical phenomena, specifically the phenomenon of colour, is briefly explored, the teaching models/textbook treatment examined and the possible links between the historical development of ideas about light and colour and classroom treatment of the ideas are tentatively developed.