THE COLOUR DISK
This experiment was suggested by Newton.
When the disk is rapidly spun, it shows the re-composition of colours into white
light, because our eyes are unable to respond rapidly enough to recognize
each colour and mix them together.
(Often the result is not pure white, it depends
on
the
way
the disk has been coloured and on the speed of the rotation)
White light is made up of all the colours
in the rainbow.
In our eyes we have colour vision cells called cones. There are three
types of cones. One is most sensitive to red light, one to green
light, and one to blue light.
The eyes see the colour
white when all three types of cones are responding equally.
