Teaching about the electromagnetic spectrum using the Herschel experiment

Abstract

A discussion of the parts of the electromagnetic spectrum, along with wave and particle models of light, are often taken as starting points in introductory physics and optics courses. Creating a spectrum and recreating Herschel's experiment verifying the presence of infrared energy is an effective demonstration for students at all levels. However, such a supposedly simple experiment has a number of potential pitfalls, which will be examined in this paper. Methods of doing the experiment both indoors and outside with simple experimental materials will be described and recommendations on best ways to link this experiment to further studies about the spectrum will be given. The use of digital cameras for near infrared imaging in a classroom setting will also be discussed briefly. Having students perform the Herschel experiment provides an excellent introduction to the history of optics and gives them experience in the scientific process. Such a guided inquiry approach can be used successfully to increase student learning and achievement in optics. © 2002 OSA and SPIE · 0277-786X/02/$15.00.