Rainbows are an excellent example of its nature’s whimsical character. A lot of research has been implemented to crack the rainbow’s colourful puzzle, with some questions still being debated in recent years. Some of the more obvious ones are of course, how are they formed? And where do the colours come from?
Whether you see the rainbow in your glass of lemonade (or vodka), above a waterfall or simply in the sky, three things must happen for you to witness the rainbow’s outstanding display of colours. Firstly, the Sun (or a source of light) must be shining. Secondly, the Sun must be behind you. And last but not least, there must be water droplets in front of you. Whenever all three of these are brought together at the right time and place, a vivid rainbow will be created.
But what actually triggers the array of colours to appear? The answer is non-intuitive I’m afraid, but simple. The water droplet, whether above the waterfall or in the sky after a heavy shower, acts a prism. It bends and reflects the light from the Sun. It then moves with a crazy speed of 300,000km per second straight to your eyes. Look at it this way: raindrops let you see the ‘intimate’ side of light – taking off its ‘clothes’ in a sort of public strip-tease – pretty much the naked side of nature.
The explanation above took me less than 15 minutes to write, despite the millennium of observations it took to fully understand it – sadly this is true of a lot of events that occur in our day to day life. These days, we’re a little more advanced compared to our ancestors in understanding the beauty of the rainbow. Many questions, however, remain unanswered, such as the appearance of twinned rainbows. But one thing’s for sure – we’ll never stop gawping at the naked side of nature. Rainbows, no matter what age we are, never cease to amaze us.