We all appreciate the stunning beauty of the rainbow, but how much more fascinating these colors become when they shimmer and change with the angle of vision as the different wavelengths of light pass through water droplets.We all know that light is not truly white at all, but made up of seven basic colours. The saying ‘Robert of York Gave Battle in Vain’ leads to the ones involved – red, orange, yellow, green, blue, indigo and violet. You only ever see these individual colours when light is refracted through prisms, and water vapor is especially good at displaying rainbows, when millions of tiny water droplets act as single prisms and set off an awesome display of colour.
Waterfalls are excellent places to get the full benefit of this naturally occurring effect. Standing well below the precipice over which the water flows, you will find your vision obscured by vast clouds of water-vapor, billions of droplets thrown up into the air by the force of the falls. Sunlight streaming through these mists will often appear as rainbows, stunningly short-lived and spectacular.
Of course any drop of water that falls can, in the right circumstance, provide an awesome view of rainbow colours, as many photographers have gone to great lengths to prove. A single drop into a pool below can provide incredible images of things the human eye would be too slow to see, using time-lapse and slow speed technologies.
The fragility of white light is made all the more obvious through the use of these techniques, and the tremendous shortcomings of human vision are horribly exposed. There is far more to see in the natural world than human capabilities allow, but at least we can appreciate the rainbows.
Three things have to happen for you to see a rainbow. The sun must be shining, Sebe behind you, and there must be water drops in the air in front of you. Sunlight shines into the water drops, which bend or “refract” the light and separate it into colors. Actually, the rays of light bend twice. As they enter the drops, the rays of light bend, then reflect off the back of the drops. Then they bend again, this time while exiting the drops. That’s when the light appears before our eyes.
Each drop reflects only one color of light, so there must be many water drops to make a full rainbow. You’ll see the brightest rainbows when the water drops are large, usually right after a rain shower. Because rainbows are light and because light rays strike everyone’s eyes a little differently, the rainbow you see will be a little different from the one someone else sees, even if he or she is standing right beside you.
Someone else a short distance away or looking from a different angle may see a much different rainbow — or no rainbow at all. Another oddity is that you might see a rainbow’s reflection in a lake without seeing any rainbow above it in the sky! That’s because you may be at the wrong angle to see the rainbow but are in the perfect spot to see its reflection in a lake.
As you can see from the spectacular rainbow effect on the spider-web in the above picture, nature never ceases to provide incredible natural works of art for us humble humans to enjoy. When she puts on a show, she does so in some of the most visually stunning ways you can imagine. If you ever get tired of being enchanted by the natural wonder of the world around you, be sure to check that you still have a pulse.
