When I set a glass prism on a windowsill and allow the sun to flood through it, a spectrum of colors dances on the floor. What we call "white" is a rainbow of colored rays packed into a small space. The prism sets them free. Love is the white light of emotion.
Diane Ackerman, A Natural History of Love
Poetry is the journal of the sea animal living on land, wanting to fly in the air. Poetry is a search for syllables to shoot at the barriers of the unknown and the unknowable. Poetry is a phantom script telling how rainbows are made and why they go away.
Carl Sandburg, Poetry Considered
A rainbow is caused when light reflects, refracts and disperses from water droplets. The results is a spectrum of colours appearing which take the form of a circle (if seen from above in the air) or an arc if viewed from ground-level. The rainbow always appear directly opposite the sun (white light source) and requires that the set of all the raindrops has a right angle between the observer, the drop and the sun. The white light entering the droplet from the sun, separates into colours as it is dispersed and exits the droplet.
In a primary rainbow, the arc moves from red on the outside to violet on the inside. The primary rainbow is caused by some of the light being refracted when entering the droplet, some being reflected while inside on the back of the droplet and some of the light then being refracted as it leaves the droplet at a specific angle. If there is a double rainbow, the colours of the second arc seen outside the primary has its colours reversed (red on the inside). This results from light being reflected twice inside the droplet before it exits.
The colours generally attributed to a rainbow, always in order of their wavelength, are red, orange, yellow, green, blue, indigo and violet.
The rainbow as a physical structure does not exist. It is an optical illusion that depends on a particular observer's viewpoint from a specific angle as water droplets are illuminated by the sun. In this way, a rainbow can never be approached (it will always be removed from the observor based on the angle of the sun's light).
[Information sourced online from Wikipedia]
In the ancient Norse worldview there are nine realms that are held in the roots and branches of the World Tree, Yggdrasil. Bifröst is the rainbow bridge that leads from Midgard (the world of humans) to Asgard, the home of the Aeisr (gods). Bifröst is guarded by Heimdall, son of Odin the All-Father and nine mothers (variances relate these mothers as nine jötunn maidens at the edge of the world or the nine daughters of the goddess of the sea). Heimdall secures the rainbow bridge against Ragnarok, the prophesied end of the world: when Heimdall loses the rainbow bridge, Asgard will fall.
The guardian of the rainbow bridge sleeps less than a bird, has extraordinary eye-sight good for hundreds of kilometres during both day and night. His sight also enables him to see the grass grow and his hearing enables him to hear the wool grow on the back of a sheep.
Related Wildwood Cards:
Card 0: The Wanderer