The rainbow is a natural phenomenon consisting of a spectrum of colors. A person standing on Earth sees the sun as a disc with a particular size and shape – a circle. When you look at it from underwater, you see another circular disc with another color pattern because of refraction, reflection, and dispersion of light waves emitting from the sun.

However, there are also rainbows in which the circle is not circular but elliptical – with an arc curving towards the upper left or right. This is because of the asymmetry of water droplets that emit light, measuring the rainbow after reflection.

The rainbow effect is most often seen at sunset by walking away from the sun. It’s also possible to make a rainbow when looking at the sun through a plastic layer or thoroughly water.

The sky is not always cloudy, which leads to a lack of rainbows. The most beautiful weather in which they can be observed occurs after precipitation (rainfall, dew) – when there are droplets in the atmosphere that can cause such a spectrum.

Rainbow is considered one of the wonders of nature and results from the refraction, reflection, and dispersion of light rays originating in the sun or other celestial bodies emitting light. The rainbow results from the refraction of sunlight. The parameter that determines its appearance is Rayleigh scattering, which ensures color distribution by deviations from violet to red.

In mathematics, a rainbow is usually represented as a disc with the center of an ellipse and its two furthermost rays as tangents.

A rainbow consists of 7 colors, but this number has been changed several times. In the 1920s, it was recognized that the spectrum consisted of seven primary colors: red, orange, yellow, green, blue, and indigo. In 1937, the American inventor Roy G Biv thought that 6 colors were sufficient to demonstrate a full spectrum – red, yellow, green, cyan (turquoise), blue, and violet. The width of the spectrum can also determine the number of colors – Newton counted 10, while many people today still think that there are 7 colors in a rainbow.

The first person who proved scientifically that rainbows exist was Aristotle, whose experiments with water droplets concluded that light is separated in a rainbow. In the past, it was believed that a rainbow is a messenger from God and shows its place in the sky in which one should pray.