Rainbows

Did you know...
It doesn't have to rain for us to see a rainbow it can be seen in the early morning dew, in the fine mist from a waterfall or in the spray of water from the ocean. But it must be from some sort of water as the rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky (or other places) when the Sun shines onto droplets of moisture in the Earth's atmosphere. They take the form of a multicolored arc, with red on the outer part of the arch and violet on the inner section of the arch. A rainbow spans a continuous spectrum of colors; the discrete bands are an artifact of human color vision. The most commonly cited and remembered sequence, in English, is Newton's sevenfold red, orange, yellow, green, blue, indigo and violet (popularly memorized by mnemonics like Roy G. Biv or (R)un O)n Y)ou G)reat B)ig I)vy V)ine

Contrary to popular belief, the light at the back of the raindrop does not undergo total internal reflection, and some light does emerge from the back. However, light coming out the back of the raindrop does not create a rainbow between the observer and the sun because spectra emitted from the back of the raindrop do not have a maximum of intensity, as the other visible rainbows do, and thus the colors blend together rather than forming a rainbow.