Rachel.
the experiment can make a good demo to prompt an inquiry, so I’s show this to a small group, let them play around (explore) with the equipment, and then see if they can devise a question that they can predict the answer to – and then try it out.
They might wonder – does it have to be a torch? could you use a laser pointer (there are often pointers in remote controls if you have an old one lying around), what happens if you change the angle of the torch -shine it in from the top, or the side, or from the bottom? etc