What is Dispersion?

The separation of white light (light from the sun) into its component colors.

The component colors:

• Red
• Orange
• Yellow
• Green
• Bue
• Indigo
• Violet

ROY G BIV

Explanation

BEFORE NEWTON

It had been thought that:

• Color was a mixture of light and darkness
• The colors seen was due to impurities in the prism
• The colors seen was a result of impurities in white in the white light.

NEWTON'S EXPLANATION

Newton's experiment on dispersion prove:

1. White light is made up of 7 colors, its component colors are:
2. • Red
   • Orange
   • Yellow
   • Green
   • Bue
   • Indigo
   • Violet
   • ROY G BIV
3. The 7 colors can be combined with a 2nd prism to produce the white light.

Physics of the Rainbow

• A rainbow is formed as a result of total internal reflection by droplets of water in the clouds
• A higher droplet totally internally reflects and disperse the white light into its component colors
• Red light from the higher droplet enters our eyes
• The lower droplets also totally internally reflects and disperses the white light from the sun
• The droplet refracts the other colors of light into our eyes
• Note that in a rainbow, the color red appears the highest while violet appears lowest
• For a rainbow to be seen the sun must be behind the observer

Christopher Seebaran (pc)