The Formation of a Rainbow – Explained

Rainbows are a beautiful display of natural colors that emerge following rainfall, spreading a delightful sense of joy and contentment among those who view them. These charming phenomena occur when sunlight peeks through the rain.

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Formation Of A Rainbow
Formation Of A Rainbow

While sunlight may seem white to the naked eye, it comprises seven distinct shades, namely violet, indigo, blue, green, yellow, orange, and red, often remembered by the acronym VIBGYOR. The phenomenon through which sunlight divides into these seven colors is known as dispersion, and the sequence of these colors is referred to as a spectrum.

A typical rainbow emerges after rain, with tiny water droplets filling the atmosphere. When these spherical raindrops intercept the sun’s rays, they function as prisms, causing the rays to refract and diffract into the VIBGYOR spectrum as they traverse the raindrops. Since each ray of light refracts at a unique angle, they diverge into seven distinct colors, forming a rainbow. This elegant occurrence affirms that white light encompasses seven constituent colors.

The Spectrum Of Light
The Spectrum Of Light

Rainbows manifest in the shape of a semi-circular arc, corresponding to the sun’s circular form. A complete rainbow encompasses both a primary and secondary arc. The primary arc commences with violet on the inner side, followed by indigo, blue, green, yellow, orange, and red. The secondary arc exhibits the reverse order, with red on the inner side and violet on the outermost.

In a full-fledged rainbow, the secondary arc lies above the primary one. This type of rainbow materializes when the sun’s rays are reflected and refracted following the initial interaction with the raindrop.

Rainbows consistently appear in the opposite direction from the sun. For a rainbow to take form, it is essential for the sun to shine immediately after rainfall. Moreover, the sun and the rainbow should lie within the same plane to be perceivable by our eyes.

More often than not, rainbows grace the sky in the early mornings or late evenings following substantial rainfall. With their vivid and beautiful sight, rainbows are a visually pleasing.

Here are some Quick Facts about Rainbows:

  • A rainbow can be described as a band of colors, ranging from red on the inside to violet on the outside, forming an arc as a result of the reflection and refraction of the sun’s rays inside raindrops. They emerge when it is raining in one part of the sky and sunny in another.
  • While many people associate a rainbow with the classic seven colors of red, orange, yellow, green, blue, indigo, and violet (VIBGYOR), it is actually composed of a continuous spectrum of colors, including those beyond the range of human vision.
  • The reason we can perceive the colors of a rainbow is that light, composed of various colors, refracts as it transitions from one medium, like air, to another, such as water within raindrops. When combined, these colors in sunlight appear white, but they disperse into the vivid spectrum we see in a rainbow when refracted.

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