A double rainbow was seen all across Chicopee Sunday morning.
CHICOPEE, Mass. (WWLP) – A double rainbow was seen all across Chicopee Sunday morning.
According to the National Weather Service (NWS), double rainbows are simply a reflection. To understand the phenomenon of a double rainbow, it’s important to understand how a rainbow is initially formed.
“As light enters the raindrop, it is refracted (the path of the light is bent to a different angle), and some of the light is reflected by the internal, curved, mirror-like surface of the raindrop, and finally is refracted back out the raindrop toward the observer,” says NWS. “This schematic represents the path of one light ray entering a raindrop at point A. As the light beam enters the surface of the raindrop, it is bent (refracted) a little and instead of continuing to point D, strikes the inside wall of the raindrop at point B, where it is reflected back to point C.”
A double rainbow can be formed when sunlight is reflected twice within a raindrop, essentially a reflection of the initial reflection.
When viewing a double rainbow, you’ll notice the rainbows aren’t actually identical — one rainbow runs in the typical order of red, yellow, green, blue, indigo, and violet. The second rainbow is a complete reversal of that classic pattern.
“The rainbow we normally see is called the primary rainbow and is produced from one internal reflection,” explains NWS. “The secondary rainbow arises from two internal reflections and the rays exit the drop the second time at an angle of around 50 degrees, rather than the 42 degrees for the primary rainbow” resulting in a second rainbow.
NWS says it’s possible for additional rainbows to be reflected but these are not as commonly witnessed.
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