It was my first big backpacking adventure. I had diligently entered every detail into a notebook. And also about the rain, six days without letting up. The rain clouds sat so low in the valleys that they blocked any view of the mountains. At one point, a furious hailstorm caught us far from cover. There was nothing we could do but stand still and wait for it to pass. The sky struck me wordless. At the head of the valley was a perfect rainbow, seven layers of light arching between two mountain peaks that had gone silver. The rainbow was so bright the spires of the spruce trees below seemed lit like candles. If light could make sounds, we would have heard a symphony.
How could something as simple as a spear of light bring such feelings of hope and optimism, when moments earlier there had been gloom and fog?
A rainbow’s startling colors, its sudden appearance in a storm wracked sky, and the graceful brush stroke of its arc: all stir emotions difficult to express. It’s easy to understand why rainbows would be seen an omens of good things to come.
The way a rainbow works: When the sun’s rays meet a raindrop, most of the light passes through the center of the drop. But the light that passes through the upper and lower parts is refracted, bending and splitting into its seven component colors, producing a rainbow.
To early Christians and Jews, a rainbow was a ray of heavenly light radiating from above. The idea of a pot of gold at the end of the rainbow may have come down from a belief that angels sit at the top playfully rolling golden coins down the rays.
The primary rainbow colors always appear in the same order from top to bottom the “VIBGYOR” you may remember from science: red, orange, yellow, green, and blue, indigo, violet. For all their suddenness, these ribbons of light do follow certain patterns. For instance:
• The best time for rainbow hunting is within three hours of sunrise or sunset, when the sun is low in the sky. Since rainstorms are more common in the afternoon, most rainbows are seen later in the day.
• When the sun is high, rain-caused rainbows are invisible except when you’re at a high vantage point, such as a mountain summit, and can view a rainbow below.
• Rainbows can form anywhere there’s falling water and sunlight.
• The sun has to be behind you to create visible rainbows, so look west in the morning and east in the afternoon.
• Chasing rainbows is futile. The angles of refraction and reflection have to stay constant for you to see the colors. As you walk towards the rainbow, it will always appear the same distance away.
Despite all the science, however, rainbows remain more within the realm of the artist than the physicist. When we stare up at a rainbow, it isn’t wavelengths of light most of us see. It’s something wondrous, a gift, a bright ribbon wrapped for a moment around the sky. And when you encounter one of the most beautiful things in nature, sometimes it’s best to be silent and look.