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Colored lights - color of objects

Decomposition of white light

1) What is white light ?

Light emitted by the Sun is white light.
Some lamps may also generate white light.

2) Décomposition of light

White light can be decomposed by a prims or diffraction grating.
- A prism is a block made ​​of glass or another transparent material having a triangular base.
- A diffraction grating consists of fine parallel striated slits, equally spaced.

White light passing through a prism gives a serie of colored lights from violet to red and with all shades of blue, green, yellow and orange that can be observed on a white screen placed behind the prism.
All these colored lights come from the white light in which they are mixed. The prism only separates colored lights but it doesn't create them.

White light is composed of a mixture of all the colored lights that exist.
This set of colored lights is the spectrum of visible light