Give children tools for exploring a concept and they almost always show me a new way to teach it. In a session of flashlight and mirror exploration, Walter began building by putting a flashlight on top of a single-eyepiece, single-mirror periscope. “Look!” he said, pointing to a beam of light exiting the periscope. He was able to see that mirrors can change the direction of a beam of light. (Click on photos to see details.)
We were using flat plexiglas mirrors, a variety of flashlights, two kinds of periscopes, and some “half” pictures drawn on paper. Before handing out the flashlights, I always caution the children that they may not shine the lights into their own eyes or anyone else’s because bright lights can damage eyesight. Usually a few children test this rule and I take the flashlights away for a few minutes. LED, or light-emitting diode flashlights, have particularly bright, narrow beam.
The “half” pictures idea comes from Make a Bigger Puddle, Make a Smaller Worm, also called The Magic Mirror Book (Scholastic 1979) and the Mirror Puzzle Book (Tarquin 1986), both by Marion Walter. Showing the children a drawing of one shoe, I tell them, “I was going to wear this pair of shoes today but I couldn’t find the other one. Can you help me find it with a mirror?” Then we hold a mirror perpendicular to the page and move it close to the shoe—ta dah! the other shoe appears (and I pretend to put them on). Other favorite images are a pizza missing a slice (make it whole or “eat” it bit by bit), an apple missing a bite, half a heart, half a moon, a soccer ball half deflated, and a broken plate. As the mirror is moved across the page, the other half is revealed (the “whole” section is reflected) completing the image and removing the bite or deflated area or broken edge from sight. As they manipulate the images the children are learning that mirrors reflect images (which are light but they don’t realize this) and the angle you hold them changes what is viewed.
Peggy