Mythology and Folklore
Rainbows have been a significant component of mythology throughout history. They have been part of the myths of many cultures around the world. In Greek mythology, the goddess Iris personifies the rainbow and serves as a messenger between the gods and the human world. In Norse mythology, the rainbow is seen as Bifrost, a bridge connecting Earth with Asgard, home of the gods. In Abrahamic traditions, the rainbow is seen as a covenant with God not to destroy the world by means of floodwater.
Rainbows also appear in the myths of indigenous peoples from North and South America, Africa, Australia, Malaysia, and ancient Persia. They often serve as bridges, pathways, or symbols of transformation. In Māori mythology, the tale of Hina, the moon, tells of a rainbow that spans the heavens2.
Scientific Explanation
Rainbows are an optical phenomenon caused by the refraction, internal reflection, and dispersion of light in water droplets, resulting in a continuous spectrum of light appearing in the sky.
The primary rainbow shows red on the outer part and violet on the inner side, while a double rainbow has a second arc outside the primary arc with the order of its colors reversed.
The scientific explanation of rainbows was first discovered by a German monk named Theodoric in 1304, who observed sunlight passing through a large globe filled with water. Modern physical descriptions of rainbows are based on Mie scattering, a theory published by Gustav Mie in 1908.
Cultural Significance and Symbolism
Rainbows have been used as symbols of hope, transformation, and diversity in various cultures. They have been featured in paintings, often with symbolic or programmatic significance, such as Albrecht Dürer's Melancholia I and Joseph Anton Koch's Noah's Thank Offering.
In modern times, the rainbow has been adopted as a symbol of hope during the COVID-19 pandemic, with households worldwide displaying home-made images of rainbows in their windows.
The rainbow is also a symbol for the LGBTQIA community, with the rainbow flag developed in 1978 as a symbol of pride and diversity.
In some cultures, rainbows are seen as pathways or bridges, such as in Roman culture, where they were believed to be the pathway taken by Mercury, the messenger god.