Light rays are made up of tiny ripples, called waves, that vary in length. These create different colors of the rainbow, or spectrum. The longest wave that we can see is red. The shortest is violet. The light that comes from the sun and light bulbs is known as white light. This sis made up of rays of many different wavelengths, mixed together. Try this project to see hoe the colours of to rainbow mix to form white light.
Steps to be taken
1. Draw a circle on a piece of white card. 2. Carefully divide it into six equal sections and colour them in this order, as shown: red, orange, yellow. Green, blue, purple or violet 3. Cut out the circle and carefully secure a thin pencil through the centre. 4. Spin it on a smooth, flat surface. As it spins, the disc will look almost white.
How it happens?
This is because the disc spins too much quickly for human eyes to pick out the individual colours. Instead, the light waves that make up the different colours merge to form light.