Life's Little Mysteries

Why Can't We Reach the End of the Rainbow?

News
By published
double-rainbow-1003-02
A double rainbow seen from Asheville, North Carolina. (Image credit: Grant W. Goodge/NOAA)

You'll never swim out to the horizon , and you'll never reach a rainbow's end. The visibility of both requires distance between object and observer.

Rainbows consist of water droplets being struck by sunlight in a certain way. Round, transparent drops of water refract and internally reflect some sunlight towards the observer. Different wavelengths of light refract (change angles) at different angles, so the white light of the sun is parsed into an orderly band of colors.

As these insubstantial pageants are but light and water, don’t go searching for the touchdown spot. The optical phenomenon depends upon you being situated a distance from the droplets, with the sun at your back.

Follow Life's Little Mysteries on Twitter @llmysteries. We're also on Facebook & Google+.