Rainbow Light Paths

The light paths associated with the primary and secondary rainbows give insight into the formation of rainbows and the order of the colors. For the primary rainbow, the light is bent by refraction upon entering a water droplet, then reflected off the back of the droplet and refracted a second time as it exits the droplet.

More detailRainbow image
Why is the blue lower than the red in a primary rainbow?
Why are the colors reversed in the secondary rainbow?
Show the different paths for a single color
Index

Rainbow concepts

Atmospheric optics concepts

References
Greenler

Schaaf
 
HyperPhysics***** Light and Vision R Nave
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Rainbow Light Paths

Rainbow image
Index

Rainbow concepts

Atmospheric optics concepts

References
Greenler

Schaaf
 
HyperPhysics***** Light and Vision R Nave
Go Back





Light Paths in Water Droplet

Of the many paths taken by parallel light rays through a spherical water droplet, several bunch together near a minimum deviation angle, and these rays together enhance the intensity at that particular angle to produce the primary rainbow. The ray which emerges lowest is often called the Descartes ray, since Decartes is credited with being the first to work out these ray paths through a spherical droplet of water. The Descartes ray is analogous to the ray at the angle of minimum deviation through a prism. All the other rays emerge at higher angles from the droplet, so they will reach the eye from droplets lower than the primary rainbow. The other rays contribute to the lighter sky beneath the rainbow and to interference effects seen in the supernumerary arcs.

Why is the blue lower than the red in a primary rainbow?
Show the paths of highest brightness for different colors

Index

Rainbow concepts

Atmospheric optics concepts

References
Greenler

Schaaf
 
HyperPhysics***** Light and Vision R Nave
Go Back




Different Angles for Different Colors

Index of Refraction
Index

Rainbow concepts

Atmospheric optics concepts

References
Greenler

Schaaf
 
HyperPhysics***** Light and Vision R Nave
Go Back