A rainbow is an optical and meteorological phenomenon that is caused by reflection of light in water droplets in the Earth's atmosphere, resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured arc.
Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.
In a "primary rainbow", the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted while entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it.
In a double rainbow, a second arc is seen outside the primary arc, and has the order of its colours reversed, red facing toward the other one, in both rainbows. This second rainbow is caused by light reflecting twice inside water droplets.
Famous quotes containing the word rainbow:
“She saw in the rainbow the earths new architecture, the old, brittle corruption of houses and factories swept away, the world built up in a living fabric of Truth, fitting to the over-arching heaven.”
—D.H. (David Herbert)
“The true harvest of my daily life is somewhat as intangible and indescribable as the tints of morning or evening. It is a little star-dust caught, a segment of the rainbow which I have clutched.”
—Henry David Thoreau (18171862)
“We have not the reverent feeling for the rainbow that a savage has, because we know how it is made. We have lost as much as we gained by prying into that matter.”
—Mark Twain [Samuel Langhorne Clemens] (18351910)