What is a secondary rainbow?

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Since a rainbow is dependent on the position of the sun, the water droplets, and the observer, everyone watching a rainbow is actually seeing his or her own personal rainbow.

The secondary rainbow has its color spectrum reversed, is outside of the original rainbow, and is significantly dimmer than the primary rainbow. A secondary rainbow occurs because an additional reflection of the light takes place inside the water droplets. Instead of reflecting once in the water droplet, the light reflects twice inside the water, reversing the order of the colors. The secondary rainbow appears between the angles 50° and 54°.


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