Activity

Shadows and mirrors

Summary
Use mirrors to shine light into a shadow, and use sticky notes or draw on the mirror to make (reverse) images in the patch of light.
Science content
Physics: Light and Sound (1)
Earth/Space: Sun, Moon, Solar System, Universe (1, 4, 6)
Materials
  • a clear sunny day (if outside) or a dim room and flashlights (if inside)
  • large sheet of light-coloured paper (if outside) or white boards e.g. foam core on stands or against walls (if inside)
  • small mirrors
  • dry erase markers
  • tissue to clean off mirrors
  • optional: sticky notes and scissors
Procedure

If this activity is run inside:
Show or challenge students to reflect the beam of a flashlight off a mirror and onto a white board. It will be easiest for them if they lay the mirror on the floor or desk, and then shine the flashlight down onto it at an angle, to make the light reflect back up onto the board (which is in front of them). Older students may also be able to hold the mirror and the flashlight and arrange the angles to reflect the light onto the board.

If this activity is run outdoors on a sunny day:
Mirrors can be used bend the sun's rays around an object and bring light into its shadow. Students may be familiar with seeing sunlight reflected off objects forming bright patches. Show students how to use a mirror to make a splash of light in the centre of their own shadow.
Outside, they may find it easier to squat down to make a large shadow, then have the sun shine over their shoulder onto the mirror, which is tilted to reflect onto the ground in front of them. Younger students might need assistance with the placement of the mirror and themselves relative to the sun. A sheet of light paper makes the patterns more clearly seen on a rough or grey ground.

Show all students that by drawing on the mirror, or by making a shape out of a sticky note, they can make patterns and shapes within the patch of reflected light.
Challenge them to write their name or an image, so that it appears right-side-up inside the shadow.

Help all students visualize the path that the light rays take, to reinforce how they are making their patterns, and how shadows are formed.

Discuss some big ideas that students are discovering: Light goes in straight lines and can be reflected. Some surfaces reflect light, some do not.

This activity can be used to demonstrate the Moon's appearance: the light areas reflect the sun's light and look white, while the dark areas (basalt lava flows) do not reflect light and look dark.

Grades taught
Gr K
Gr 1
Gr 2
Gr 3