My son contacted me yesterday to ask if I was seeing the double rainbow outside after a long afternoon of heavy rains. As I looked outside, I was struck first by the intensity of color and light, much more visually intense than any rainbow I’ve seen of recent memory, but secondly the aspect of a double rainbow, I don’t recall seeing one before.
Despite my lack of memory about seeing double rainbows, from what I found online, this phenomenon is relatively common, especially at times when the sun is low in the sky such as the late afternoon, which this was the timing exactly (about 6:00pm). I also learned that a key feature of double rainbows is that the color sequence in the second rainbow is reversed from the first one. Let’s take a closer look below to see this aspect. If you look at the inside rainbow, the colors from right to left range from blue, green, yellow, orange and then red, while the second outside rainbow then starts with red and works backwards, to orange, yellow, green and blue on the far outside. Why is this? Scroll down for more …
First of all, a rainbow happens when the sun light hits a raindrop and the light reflects off the inside of the droplet, separating into different wavelengths which creates the separate colors. A double rainbow occurs when the light is reflected twice in the drop. The fainter secondary rainbow has the colors reversed because the light gets reflected twice inside the raindrops; the second rainbow is a reflection of the first rainbow and the color order reverses.
Another topic that my son initiated was: do double rainbows have any symbolic meaning? Rainbows in general tend to have a spiritual belief attached that they serve as a sign of hope, new beginnings, and a transformation. This can be traced back to the Bible story of Noah and the Ark, in which they saw a rainbow after the great worldwide flood and it was believed to be God’s way of promising that there would never again be a flood of such magnitude. I also see the suggestion that since a rainbow is considered a sign of good luck, a double rainbow means double the luck and that abundance is on the horizon.
Or, it could just mean that the light was reflected twice in the rain drop. How superstitious are you?
Did you notice how the area between the two rainbows appears to be darker than the sky inside the first rainbow? There’s a reason for this, and it has a name: “Alexander’s Band.” It’s named after Alexander of Aphrodisias who first described it in 200 AD. The scientific explanation is that this darker band occurs because as the sunlight goes between the different angles of the primary and secondary rainbows, the sunlight gets scattered by the raindrops away from the view on earth, making that area darker. If you want to investigate that concept further, check this out.
