The Electromagnetic Spectrum
Light, Sound and Waves

Teaching story - campsite shadows

Teaching Guidance for 11-14 Supporting Physics Teaching

Camp site shadows thrown by beams of light from the Sun

We're sure you'll find a story like this one to share with your class.

Recently I went on holiday to central Southern France. We were camping on a site in the Lot valley and on each side of the site there were high limestone cliffs. The weather was very hot during the day and towards late afternoon, the Sun gradually sank down behind the cliffs on the south side of the valley, creating a shadow. The fascinating thing about the shadow was the absolute sharpness of the line between light and dark, which crept across the camp site. On the dark side the Sun's beams were blocked out by the cliffs and on the other side the Sun's beams fell on the meadow. I couldn't help thinking that the light had travelled 150 million kilometres from the Sun, but the line between dark and light was clear cut, with no sign of blurring where the beams might have wobbled from their straight line paths as they travelled down from the edge of the cliff hundreds of metres above.

Teacher Tip: Work up a good story about shadows – perhaps with images to back it up.

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