Rainbows are one of the most supernatural phenomena which exist. In our childhood, we chase rainbows expecting to catch a glimpse of a pot of gold or leprechaun. Rainbows are phenomena that result from light refraction, reflection, and dispersion of water droplets.
This generates a multi-colored arc in the sky which is seen from Earth as a rainbow. Even it appears as if a rainbow is a specific distance from the person seeing it, it is just an optical illusion appearing because of the specific angle to the water droplets in relation to the light.
Rainbows can be seen whenever there are any water drops in the air and the sunlight shining from behind an observer at a low-altitude angle. Therefore, rainbows are often observed in the eastern sky during the early evening and in the western sky during the morning.
The most extraordinary rainbow displays occur when half the sky is still dark with the raining clouds, and the observer is at a point with a clear sky in the sun direction. The result is a luminous rainbow which contrasts with a darkened background.
During such great visibility conditions, the bigger but fainter secondary rainbow is usually seen. It appears approximately 10° outside of the main rainbow, with inverse order of colors.
The rainbow effect is also normally seen near fountains or waterfalls. Additionally, the impact can be artificially developed by dispersing water droplets into the air during any sunny day. Rarely, a nighttime rainbow, lunar rainbow or moonbow, can occur on strongly moonlit nights. As humankind visual perception for color is poor in low-light, moonbows are usually perceived to be white.
It is hard to photograph the full semicircle of the rainbow in one frame, as this would need an angle of view of 84°. For a 35 mm camera, a broad-angle lens with the focal length of 19 mm or less would be necessary.
Now that software for stitching many images into the panorama is readily available, images of the whole arc and even secondary arcs can be developed moderately from a series of overlapping frames.
From above the earth like in an airplane, it is at times possible to observe a rainbow as a complete circle. This phenomenon can be easily confused with a glory phenomenon, but a glory is often much smaller, covering only 5 to 20°.
The sky inside a major rainbow is always brighter than the sky outside of the bow. This is due to each raindrop is a sphere, and it distributes light over a whole circular disc in the sky. The radius of the disc is based on the wavelength of light, with the red light being scattered over a bigger angle than blue light.
Over most of the disc, dispersed light at any wavelength overlaps, resulting in the white light that brightens the sky. At the edge, the wavelength dependency on the scattering enlarges the rainbow. Light of major rainbow arc is 96 percent polarized tangential to the arch. Light of the second arc is 90 percent polarized.
A rainbow isn’t something which can be approached or touched. It will vanish at the wrong angle. It is also possible to see rainbows in the fog, dew, mist, spray and the rain.
The major colors of a rainbow include Red, Orange, Yellow, Green, Blue, Indigo, and Violet. This is often memorized by special mnemonics, like ‘Roy G. Biv’ – every letter represents the first letter of the major 7 colors of the rainbow.
Nobody sees colors the same, everyone’s eyes react differently based on how much light there is, so some individuals may see more colors than what you see. Besides the bending of light, nature has also hidden some other wonderful facts as well.
Since Summer and Spring are best times to spot rainbows, here are some interesting facts to celebrate everything rainbow!
Interesting Facts About Rainbow
1. It is believed that rainbows were named depending on their shape. The arc appears like a bow (as in bow and arrows), and it was always raining when the phenomena appeared.
2. Despite old folk tales about pots of gold and leprechauns at the end of rainbows, you will never reach the end of a rainbow. Rainbows seem to move as you move since the light which forms the rainbow does so at a particular angle and distance from the observer — so that the distance will always remain same between you and your rainbow.
3. You cannot see all the colors of a rainbow. Beyond those classic seven colors (ROYGBIV), a rainbow is really made up of a bigger continuum of over 1 million colors — including colors you have ever seen, even those you have not seen!
4. Rainbows are hardly seen at noon. Rainbows are very common in evenings and mornings. To form a rainbow, sunlight requires striking a raindrop at almost 42 degrees. That is unlikely to occur if the sun is higher than 420 in the sky, based on the information provided on the website of the National Oceanic and Atmospheric Administration (NOAA).
5. Rainbows have really contributed to ancient myths. The Greeks believed that the rainbow created a bridge between heaven and earth.
6. On very rare occasions the moon’s light will generate a rainbow effect at night, known as a moonbow. Despite the fact that all we can easily see from Earth is white light, all 7 colors are very present.
7. Rainbows often appear near waterfalls and in the tropical regions of the Earth.
8. From an airplane, a rainbow will look like a circle. We can only see a portion of it on land.
9. Earth is the only planet in the solar system where rainbows are possible.
10. Scientist Isaac Newton explained more about the formation of a rainbow.