DIY Periscope - Reflection of Light

Demonstrate how light can be reflected using mirrors to see over or around obstacles by building a working periscope.

What you need

• Cardboard box or cereal box
• 2 small mirrors (or mirror pieces from an old compact)
• Scissors or craft knife
• Tape or glue
• Ruler and pencil

How it works

Light from the top reflects off the first mirror and then off the second mirror to reach your eyes. This is how periscopes are used in submarines or trenches to see without being seen. It is a practical use of the laws of reflection.