Scientific exposure to the sun
Data Harvest's EasySense Q ultraviolet sensor lets pupils see what was previously, quite literally, invisible to them. I generally use them with Year 10 groups, and start by looking for sources of UV light in the laboratory. The pupils soon discover that fluorescent lighting gives out a small amount, and that digital projectors give out even more.
However, when they go outside, they are hit by the overwhelming power of the sun and that's when they really get fired-up. They start formulating and researching their own questions, initially investigating things like how much UV we are exposed to in the shadow of a tree or when the sun goes behind a cloud; how much UV passes through our clothing, and is UV reflected from brickwork or glass?
The answers to these questions are thought-provoking and inspire pupils to perform more detailed investigations, such as smearing acetate sheets with sun creams and comparing the different sun protection factors. They soon recognise the need to refine their experiment by controlling, for example, the amount of cream they put on.
Investigating how efficient different types of sunglasses are at absorbing UV, and comparing normal clothing to UV protective clothing, are also worthwhile investigations. The experiments are easier to control in the laboratory, but pupils find it more exciting and meaningful to use the sun as the source.
Because the new specifications promote relevant scientific enquiry and evaluation in terms of risk, there is a real need for such open-ended investigations. Following Every Child Matters, this is a perfect time to let pupils find out for themselves about an aspect of science that can affect their health.
Director of Science College, Camborne Science and Community College, Cornwall