After his experience with planetary motion, Isaac Newton grew
interested in optics, the branch of science dealing with the
behavior of light. In his first experiment, Isaac darkened his room
and made a circular hole in the window shutters of his room. Then
he placed a prism in the path of the sunbeam, which caused the
light to refract against the wall that was opposite the window
shutters. The colors always appeared in the same order on the wall
- red, orange, yellow, green, blue, indigo and violet. The colors were in a
rectangular shape although the hole in the window shutter was in
the shape of a circle. Isaac concluded that the prism bent the
colors. It bent the red light the least and the blue light the
After the first experiment, he tried another experiment using
two prisms. This time, he placed another prism upside-down in front
of the first prism. The result this time was a circle of white
light on the wall.
For his third experiment, Newton used a card with a hole in it,
which he held between two triangular prisms. Only the red light
passed through the hole. Isaac repeated this experiment with other
colors: orange, yellow, green, blue, indigo, and violet. The
isolated color was the only color that showed on the wall.
Newton concluded from the three experiments that light rays are
made up of tiny particles. He learned from his first experiment
that white light is made up of the seven colors of the rainbow -
red, orange, yellow, green, blue, indigo, and purple.