QUICKLY ! Get that pot of gold boys… Geilston Bay, January 2011. Rainbows: optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines on to droplets of moisture in the Earth's atmosphere; or something infinitely more sinister? In Greek mythology, the rainbow was considered to be a path made by a messenger (Iris) between Earth and Heaven. In Chinese mythology, the rainbow was a slit in the sky sealed by goddess Nüwa using stones of five different colours. In the Epic of Gilgamesh: the rainbow is the "jewelled necklace of the Great Mother Ishtar" that she lifts into the sky as a promise that she "will never forget these days of the great flood" that destroyed her children. In Norse Mythology, a rainbow called the Bifröst Bridge connects the realms of Ásgard and Midgard, the homes of the gods and humans. In Hindu mythology, the rainbow is called Indradhanush, meaning "the bow of Indra, the god of lightning, t...