It is possible to split the Sun's visible light into its separate colours, producing a rainbow effect.

You will need
a) a piece of white cardboard
b) a bowl of water
c) a very mirror
d) a piece of stone; and
e) a very bright, sunny day.

Steps

1. Place the bowl of water in a very sunny position. Put the mirror into the bowl and lean it against the side. You can also put a stone into the water to stop the mirror from slipping.

2. Adjust the angle of the mirror so that a strong beam of sunshine falls on it surface. Move the cardboard around in front of the bowl, until a reflected "rainbow" appears on it.

3. Visible light is refracted as it enters the water. It is then reflected by the mirror and refracted again as it leaves the water, producing a rainbow effect on the white cardboard.