The EM spectrum
Considering that light is just a small part of a much larger family of waves can really enhance this subject, particularly if there is a focus on some of the applications of these waves, such as in medical physics. Even so, other than light, these waves cannot be seen by humans directly and so it can be hard for students to imagine that they are there. For example, does something really come out of the end of a television remote control? It doesn’t look like it (the answer is yes, obviously, nice trick to show this coming up).
Many of the experiments that are carried out in schools in this topic relate to the behaviour of light. This is often simply because they are the easiest to find equipment for and carry out. This can lead to the idea that the behaviour observed (e.g. reflection, refraction) is that of light, not all electromagnetic waves. Where possible the behaviours should be shown with other electromagnetic waves or the connections made. An example might be that you can change the channels of a TV using an infra-red remote control that is pointed at a wall on the other side of the room. Point most digital cameras at the end of a remote control, push a button on the remote and you can ‘see’ that something is coming out the end.
This topic mainly focuses on visible light to learn the behaviour of the all waves in the spectrum. Students will have the opportunity to learn about lenses and optical arrangements. They will use ray diagrams, but won’t need to learn or use the equations.
Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS, SSERC or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.