National Find a Rainbow Day

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Can you find the double rainbow? (Click on image to enlarge it.)
Photo Credit: https://www.holidayinsights.com/moreholidays/april/find-rainbow-day.htm

The month of April brings spring showers. After those showers, the sun comes out and a rainbow often appears. Each year on April 3rd, National Find a Rainbow Day challenges us to look to the sky and find a colorful ray of hope cast across it.

A rainbow is a spectrum of light in the form of a multicolored arc, appearing in the sky, that is caused by both reflection and refraction of light in water droplets in the Earth’s atmosphere. Rainbows always appear directly opposite of the sun. The light is refracted (bent) when it enters a droplet of water (which acts as a prism), then is reflected inside on the back of the droplet and refracted again when leaving it.

A rainbow has seven colors because water droplets in the atmosphere break sunlight into seven colors. When light leaves one medium and enters another, the light changes its propagation direction and bends. Red is the color that is visible on the outer part of a rainbow and violet on the inside of a primary rainbow.

In the rainbow (primary rainbow) light emerging from a water droplet, the shorter wavelength (violet) is diffracted more in comparison to the longer wavelength (red). Accordingly, when looking from the left side of the figure (seen from the direction with your back to the sun), the light emerges at lower angles.
SOURCE: https://www.shimadzu.com/an/service-support/science/010912/010912a.html

For those of you who may want to delve deeper, please view the Physics of Rainbows.

Some relevant factoids and folklore to drop into conversations today –

  • The word rainbow originates from the Old English renboga – ‘regn’ meaning rain and ‘boga’ meaning bow.
  • The basic scientific explanation for rainbows dates to Persian physicist Kamāl al-Dīn al-Fārisī and, independently, German physicist Theodoric of Freiberg in the 14th century.
  • Who remembers the science class mnemonic Roy G. Biv?  Teachers used it in hopes that we would remember the sequence of colors in a rainbow: red, orange, yellow, green, blue, indigo, violet.
  • Generally speaking, rainbows in American Indian cultures are seen as a sign of good fortune, hope, and a connection to the spirit world.
  • In Hawaiian folklore, rainbows symbolize the veil between the realms of the gods and the realm of humans.
  • In Irish legend, Leprechauns bury pots of gold at the end of the rainbow, but since a rainbow can only be seen at a distance, the gold is forever illusive.

Perhaps listen to the classic song, Somewhere Over the Rainbow, sung by Judy Garland.

Go forth on this day in exploration for and celebration of one of nature’s most spectacular meteorological phenomena.

Happy viewing!

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