When we look at the sky on a cloudless sunny day, it is not hard to say that the sky appears blue, but have you ever wondered why the sky appears blue?

There are 78% nitrogen and 21% oxygen in the atmosphere and the remaining 1% is mostly argon gas and water vapor. There are also dust, ash and pollen particles in the atmosphere. Rays from the sun appear white before breaking into the atmosphere and contain all the colors of a rainbow.

When Isaac Newton was only 23 years old, he observed that in a dark room, a color spectrum was formed by passing the sunlight coming from a small hole through the prism.

When the rays of light enter the atmosphere they multiply into the particles in the atmosphere and scatter. The main reason why the sky is blue is the so-called Rayleigh scattering. British physicist Lord Rayleigh found that short wavelength light scattered more than long wavelength light. The wavelength of the human eye is between 400nm and 700nm and this part of the electromagnetic spectrum is called visible light. Since the wavelength of all colors is different, the scattering in this case will not be the same in all colors. The most scattered rays are purple and blue rays with a minimum wavelength.

Well, if the result is scattered together in purple and blue colors, why do we see the sky blue, not purple? The answer is that the purple light in the rays coming from the Sun is less than the blue light. As a result, the blue rays spread in all directions make the sky look blue.

Resources

http://www.physics.org/article-questions.asp?id=108

http://www.livescience.com/32511-why-is-the-sky-blue.html

http: //spaceplace.nasa .gov / blue-sky / en /