As nature’s one of the most splendid creations, Rainbow has inspired many poems, songs, paintings, and other forms of art. It is a very simple scientific phenomenon of bending or refraction of light that creates an amazing spectrum of colors while passing through water droplets.
How rainbow actually formed was unknown until the 17th century, when Sir Isaac Newton discovered the seven spectra of light. When this gorgeous arc of seven colors (Violet, Indigo, Blue, Green, Yellow, Orange, Red) appears in the sky, it brings a smile on the face of everyone. There are some other fascinating facts too about these rainbows. Let’s uncover those in this read about Rainbow.
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25+ Fascinating Facts About Rainbow
A multi-colored arc that we see in the sky is a rainbow. It is not an object but an optical phenomenon. You cannot touch it or feel it as it has no physical existence. It is made up of light that reflects and bend. You can never reach at the end of a rainbow as it moves along with the view and does not have a static or stationary position in the sky.
The word “Rainbow” is derived from the Latin word “arcus pluvius,” which refers to a “rainy arch.” It is called rainbow because its shape looks like an archer’s bow. It is the universal symbol of peace and harmony and also renewed hope.
A rainbow arch becomes visible to a person when the light gets refracted at a precise 42 degrees angle in the opposite direction of the Sun. This refraction of light at this angle is the major reason that we can see the seven bands of white light with our naked eyes. When the position of the Sun is lower, the rainbow will be seen at a higher location in the sky.
When the light passes through a raindrop, it also creates a rainbow which we can’t see due to its small size. When there are reflection, refraction, and dispersion of light in millions of water droplets, it creates a spectrum of light which becomes visible as a rainbow.
The primary rainbow normally appears after a rainstorm, but they can occur wherever light is being bent inside of water droplets. The Sun is equally important. It requires white light, water (denser medium), air (less dense medium), and conditions to help refraction occur at 42 degrees! It can also be seen in the mist, spray, fog, and dew.
We are taught in childhood that the bending of light or refraction creates a rainbow. However, the reflection of light has an important role in the formation of the rainbow. Light is refracted when it enters the raindrop, and then it is reflected inside the drop and again refracted as it goes out of the drop.
A rainbow appears in the sky when it’s raining in one part and sunny in another part of the sky. You will also see a much brighter sky below the rainbow than the sky above the rainbow. In this case, it becomes a divider rainbow.
Rainbow can be seen only on the planet Earth in the whole solar system. In ancient times different civilizations had different beliefs about rainbows. According to Greek mythology, the rainbow is a bridge between heaven and Earth created by the Iris, the goddess of rainbow, linking us to the immortals. In the western culture looking at a rainbow is considered lucky while the ancient people of Serbia believed that it was the bow of Storm God. For Arawak Indians of South America, rainbow seen over the ocean is acknowledged as a fortunate sign.
It was Scientist Isaac Newton who explained how a rainbow forms. He identified the seven colors of the visible electromagnetic spectrum that make up white light altogether. Those seven colors are red, orange, yellow, green, blue, indigo and violet, all of which are present in a rainbow in the same order. The acronym ROY G BIV is used to remember these colors as well as their order of appearance easily. It is also referred to as VIBGYOR in reverse order. The colors in a Rainbow blend into the next without a hard boundary.
Rene Descartes was the first who realized in 1637 that Rainbows were caused when light from the Sun gets split into different colors by raindrops.
Homer, the Greek epic poet, believed that Rainbows were made of only a single color, Purple. At the time of the Renaissance, people thought there were four colors: Red, Blue, Green, and Yellow. Till date, the average Chinese people claim that rainbow has only five colors.
We view rainbow as a semicircle; however, it is a full circle of light. If we see it from very high up in the sky, such as on an airplane, a rainbow in a complete circle will be visible. As most people see a rainbow from the ground, it appears as a semicircle. However, it is difficult to take a photo of the complete semicircle of a rainbow in one frame.
Rainbows are hardly seen at noon because rainbow occurs when light strikes raindrop at exactly 42 degrees, which is not possible in the noontime as the sunlight hit the atmosphere at an angle higher than 42 degrees. In winter also we cannot see rainbows because as raindrops freeze into snowflakes, fewer raindrops fall.
No two people can see the same rainbow, and that makes rainbows so special. How the light is being bent and reflected you matter, and that is why everyone sees something different. A person may be standing just next to you but still sees the different rainbow because raindrops visible to him are different from what is visible to you. You will be surprised to know that even one of our eyes sees slightly different rainbows than the other.
A “double rainbow” is also visible as a second, and much fainter arc outside the primary arc. It is primarily caused by the reflection of light twice inside the water droplets. Because of the double reflection, the colors of the second arc are inverted with violet on the outer edge and red on the inner edge.
Light rarely gets reflected 3 or 4 times within a water droplet. When this happens, it produces tertiary (third) and quaternary (fourth) much fainter rainbows in the direction of the Sun. Therefore, there can be a combination of rainbows, too.
You may have heard the term Alexander’s Band associated with a rainbow, but technically it is not a rainbow. The dark, unlit sky in the middle of the primary arc and the secondary arc is called Alexander’s band, which was named after Alexander of Aphrodisias who first described it in 200 AD.
Similar to the rainbow, “fogbow” is created by cloud and fog droplets which appear to be almost white with very faint colors. However, compared to a rainbow, it is quite large and much broader.
Moonbows is a rare lunar rainbow or nighttime rainbow that occurs when the light of the moon reflects through the raindrop. It’s same as a rainbow arc, but you see it all white even though all seven colors faintly exist.
A red rainbow is very rare and hardly seen. It is also called “monochrome rainbow,” which is formed after rain showers during sunrise or sunset.
Cloud rainbows occur from small water droplets in clouds and damp air instead of raindrops.
A supernumerary rainbow or stacker rainbow is an infrequent phenomenon, consisting of several faint rainbows of an unusual pattern of pastel color bands on the inner side of the primary rainbow, and in the rarest occasion, outside the secondary rainbow as well.
Some other rare rainbows are upside-down rainbows or circumzenithal arcs that form when the sunlight reflects through ice crystals and twinned rainbow, two rainbow arcs that split from a single base.
Hawaii is home to the highest number of Rainbows than any other place on Earth. Rainbows occur more frequently in tropical locations and by waterfalls, sea sprays, and geysers.
Titan, the Saturn’s moon is ideal for the formation of a rainbow due to its moist atmosphere. However, the angle of dispersion of a Titan Rainbow would be about 49° instead of 42°. The most romantic part is that rainbow occurs right on the surface of Titan!
The longest-lasting rainbow of the world was seen over Sheffield, England on 14 March 1994 where it lasted from 9 in the morning to 3 in the afternoon.
There are many legends and myths about the rainbow originated in earlier times such as the angels put a pot of gold at the end of the rainbow to be obtained only by nude man or pointing towards a rainbow brings bad luck, and that it can even change a man into a woman or vice versa.