Strategy Nine: Edible Science (Light Waves)

This week in our Teaching and Learning briefing, a Science teacher presented us with a ‘wave machine’. From our seats, we could see a long piece of tape attached to two chairs. From this, skewers and sweets extended on either side. Only when the member of staff tapped on the tape did it begin to dawn on us what he was demonstrating – light waves! The tape undulated and rippled, creating swirling patterns as the skewers demonstrated peaks and troughs that students needed to be able to discuss in science when explaining the manner in which light travels.


If a room full of adults, at eight o’clock in the morning, can be fascinated by tape, skewers and sweets, it is easy to imagine the enthusiasm that this would inspire in a class of Year 8.


When learning about light waves, children struggle with several key ideas:

  • Visualizing that light travels in straight lines
  • The waves have crests and troughs
  • Different amplitudes effect the wavelengths of light
  • Light disperses depending on the different wavelengths

These ideas are difficult for students for one key reason: you can’t see light waves in action. It is very hard to understand something that is impossible to see. It is all well and good looking at an illustration on a page but sometimes that simply isn’t enough. Science is one of the subjects where students can have a huge amount of physical interaction with the topic at hand. You can dissect, explode, set fire to – the list goes on for how you can understand a concept in these lessons.


The students were given minimal instructions and expected to use trial and error to create their light wave machines. By talking through the process, they were able to verbalize not only their successes but also their struggles. This allowed for targeted teacher intervention to address misconceptions. Each group were also given different lengths of wave machine to build, meaning that once they were all constructed, they could all try out different ones and see the different types of waves created.


As an additional challenge, students were able to apply the visual patterns to other areas of Science. What about DNA, for example? Could the same wave pattern be seen in the double helix structure? Or the sea waves? It prompted follow up questions of how does someone measure these light waves? What types of light create different waves?


While it might be difficult to create edible models of rhyming schemes or algebraic formulas, perhaps the main take away from this concept is about fun. Students learn more when engaged, this is of course known. However, when confronted with a complex task, fun becomes all the more important. Often, it is our instinct to handle difficult topics through teacher exposition where we impart our endless wisdom in to their waiting minds. However, instead we might consider that making these very difficult topics also the most fun may in fact prove to me far more effective.