Did you ever want to know,
what exactly is a rainbow?
What is it that produces this amazing sight?
– Just dispersion of the light.
How does it happen, what causes it to be?
What is the origin of what we call in Irish bogha báistí?
Sunlight enters raindrops,
gets refracted and internally reflected.
Refraction causes different wavelengths to be dispersed at different angles.
Hence the different colours of light it untangles.
Red is refracted least.
Violet is refracted most.
In between you get orange, yellow, green, blue, and indigo.
Resulting in the seven colours of the rainbow.
But if you are to see it,
Three conditions must be met.
First, it must be raining.
Second, the sun must be shining.
And you must be between the sun and the rain.
Otherwise your rainbow search will be in vain.
At rainbow’s end there is no gold.
Unless you count the beauty you behold.
And really you should comprehend,
A rainbow forms a circle, so rainbows never end.