Course: Science Subtest I
Lesson: Optics and Waves
Topic: How We See      Page 17 of 27  

To separate the colors present in white light, one can shine the light through a prism. The different wavelength components of the white light travel through the glass at different speeds (this is called dispersion) and emerge from the prism at different angles.

White light enters the prism at right. The spectrum of colors emerges at left. Some light is reflected to the upper right and down. Credit: Wikipedia