Kaleidoscope

Follow these instructions to make your own kaleidoscope and have fun with reflections.

• 5 June 2006 | Updated 14 October 2011

• What you need 
• What to do 
• What's happening 

The word kaleidoscope means 'seeing beautiful shapes'. Images of the outside world pass through a kaleidoscope to your eye but they change on the way. Through lenses and mirrors, the kaleidoscope bends and distorts light waves.

What you need

To make your own kaleidoscope you will need to gather:

• three rectangular pieces of mirror or mirrored cardboard cut to the same size (about 15 cm long and 4 cm wide)
• some tape
• greaseproof, tracing or baking paper
• plastic kitchen film or an overhead transparency sheet
• scissors
• sequins, confetti or coloured paper.

What to do

1. Tape the mirrors together along the long sides to form a triangular tube with the mirrored surfaces on the inside. It's easiest if you leave a two millimetre gap between each mirror.
2. Cover one end of the tube with greaseproof, tracing or baking paper. Secure this with tape.
3. Place the confetti, sequins or very small pieces of coloured paper onto the outside of the paper.
4. Stick a piece of clear plastic film or transparency on the very outside over the small coloured pieces to ensure they will not escape.
5. Point the kaleidoscope down at a bright light source. While looking through the viewing hole, rotate the kaleidoscope so the confetti or sequins move about. You will see beautiful shapes that constantly change.
6. You can experiment with different coloured cellophane filters, or increase the number of mirrors used to build the tube.

What's happening

A kaleidoscope is made from mirrors placed at angles to each other. The viewer looks in one end and light enters the other end. This light is reflected again and again by the mirrors.

Light bounces off a surface at exactly the same angle at which it hits the surface. As the tube is rotated, the tumbling coloured objects present the viewer with varying colours and patterns. These show up as symmetrical patterns due to the reflections in the mirrors. When the mirrors are set at 60 degree angles, it creates six sets of reflected images.

This activity and others like it are featured in The Helix: a science magazine for ages 10+.