Rainbow Hunting

“It’s a double rainbow.” That’s right, were talking about rainbows and there is such thing as a double rainbow.

Rainbows always come out after it rains or its still dewy out.  That is why they are so commonly associated with the Irish and leprechauns.  Think of the weather in Ireland, its wet.  When sunlight passes through the water in the air it starts to bend.  When the light is being bent, the white light is being divided into its component colors making it convey all the “colors of the rainbow”

You guys may be saying, “I conquered third grade, I know how a rainbow works.” But do you know how a double rainbow works?

Secondary rainbows, as they are formally titled, happens when the light is reflected twice inside a rainbow, making a rainbow from a rainbow.  The daughter rainbow is fainter than the mother rainbow and the colors are displayed in reverse order because of the double reflection (kind of like a mirror’s image in a mirror).  Secondary rainbows appear ten degrees higher than primary rainbows, which appear between forty and forty-two degrees above the horizon.  Third and fourth rainbows have been observed, and thirteenth rainbows exist in theory.

Tips For Rainbow Hunters:

Rainbows exist because of sunlight, raindrops, and geometry, so your placement is important.  Draw on a piece of paper an angle of about forty degrees, with the initial ray representing the horizon and the terminal ray representing the rainbow.  That’s the same position you want to see a rainbow.  The arc of the rainbow is always opposite of the sun.  Obviously, there will be no rainbows when the sun is at ninety degrees because the position opposite of the sun at that point would either be underground or the other side of the globe.  Basically, make sure the sun is always behind you and don’t go rainbow hunting at high noon.

Since rainbows exist only to their observers, you cannot walk under a rainbow.  I repeat, it is impossible to walk under a rainbow.

Any pilots out there?  You have the possibility of experiencing a full circled rainbow.  Unlike us stuck on the ground viewing only an arc, or slice, of the rainbow, if you pilots position yourselves just right you get to see a rainbow in a complete circle, because the horizon is not creating angles with the sun for you.

Who says rainbow hunting is a day job? Moonlight is sometimes bright enough to create the image of a rainbow. Lunar rainbows, as they are called, appear as faint white arcs.