Color

Light Dispersion

First, let us see three experiments that a great scientist, Isaac Newton, ever did.

Experiment 1
our need: enough sunlight, a prism of glass

Step:
Just let sunlight go through that prism.

Picture 1

Experiment 2
our need: a convex

Step:
In other side of the prism of glass, we use a convex.

Picture 2

Experiment 3
our need: another prism of glass

Step:
In other side of the prism of glass, we use another prism of glass, instead.

Picture 3

Result:
In these experiments, he found that white light can be dispersed.
And he take seven color from spectrum as primary colors.

• We thought that Newton pass a beam of sunlight through a prism of glass, producing a continual  spectrum at first, but later Fraunofer found that several thin black lines exist in this spectrum. We name these lines after Fraunofer. The reason why black lines exist is that there is some gas around sun to absorb the light of certain wavelength.