A rainbow can be explained as occurring when sunlight and rain combine in a special way, resulting in us being able to see all the colours of the light spectrum. Scientists tell us it’s caused by the refraction, reflection and dispersion of water droplets resulting in an arc of colour appearing in the sky. The colours always appear in a certain order – red, orange, yellow, green, blue, indigo and violet – which people tend to remember through the mnemonic ‘Richard of York Gave Battle In Vain’ or the acronym ‘ROYGBIV’. There are different kinds of rainbows: secondary rainbows are caused by a double reflection of sunlight inside the raindrops, and are centred on the sun itself and so a double rainbow consists of two separate and concentric rainbow arcs whereas the very rare twinned rainbow appears as two rainbow arcs that split from a single base. Technically a rainbow is actually a full circle, but from the ground, only its upper half can be seen, so we tend to think of rainbows as being semi-circular.
Alan spoke about how rainbows are perceived in different cultures (in Hindu mythology, the rainbow is portrayed as an archer’s bow; in Norse mythology a burning rainbow bridge called the Bifrost connects Midgard (earth) with Asgard, home of the gods, for example.) Nowadays, the rainbow is the symbol of Gay Pride and is also the youngest section for girl guides! For those of us of a certain age, the word ‘Rainbow’ also conjures up images of a children’s TV programme featuring George, Zippy and Bungle!
For Christians, the rainbow is important for giving us further insight into God’s faithfulness and trustworthiness. It reminds us that we have hope and can trust in God.