Happy St. Patrick’s Day! With festivities in full swing, we thought now would be a good time to discuss one thing frequently associated with the Irish holiday. No, not four-leaf clovers. We’re talking about the breathtaking optical trick that cannot exist without water: a rainbow!
Did you know it’s impossible to reach the end of a rainbow? We’ll explain all that and more.
Connection to St. Patrick’s Day
Why are leprechauns and rainbows commonly associated with St. Patrick’s Day and Irish culture, anyway? In Irish folklore, leprechauns are often seen urging people to seek out the pot of gold they’ve left at the end of a rainbow.
Here’s the thing, though: The end of a rainbow in unreachable, because whenever you move, the rainbow moves with you! Despite the fact that a leprechaun’s gold is unattainable, rainbows remain a staple of St. Patrick’s Day and the luck of the Irish.
A Complex Science of Water and Light
Every rainbow is made up of two simple ingredients: water and sunlight. However, the process of creating a rainbow isn’t as simple as merely mixing water with light and expecting a colorful arc. The sun’s rays are made up of many different colors, but we most often perceive them as white light. When the colorful rays of light hit raindrops at a specific angle, the light both reflects and refracts through each individual raindrop as it passes through. This allows the beautiful colors of the rainbow to disperse and become visible to the human eye. Yay, science!
Double Rainbow? Triple Rainbow? Quadruple Rainbow
Double rainbows occur when the light passing through a raindrop refracts more than once. It’s even possible for three or four refractions to occur within a single drop, resulting in multiple rainbows. This is incredibly rare, though, so consider yourself extremely lucky if you witness one.
You Can Make Your Own!
If you don’t feel like waiting for a rainstorm to pass in order to see a rainbow, you’re in luck. As mentioned earlier, all it takes to create a brilliant rainbow is a bit of water and sunlight. Grab your garden hose on a sunny day, face away from the sun and spray a fine mist—a rainbow is more than likely to form before your eyes!
Exclusively Earthly Wonder…Maybe?
Arguably one of the coolest and most unique facts about rainbows is that only Earth’s atmosphere is capable of creating and sustaining the optical visual of a rainbow. Some scientists think Saturn’s moon, Titan, is wet and humid enough for the creation of rainbows, but there likely isn’t enough direct sunlight for it to happen. For the time being, us Earthlings have some serious solar system bragging rights.
Happy St. Patrick’s Day from all of us at Aqua! Wherever you are, we hope you catch a glimpse of a rainbow very soon. Just remember: Don’t go chasing it and expecting to find gold!