Why is sky blue ? Essay for class 12th

Wondering why Sky is blue in color ? The color of the sky has been a subject of curiosity for humans since ancient times.

While the sky may appear to be a simple blue canvas, the actual explanation for why it appears blue involves a complex interplay of physics and atmospheric chemistry.

In this essay, we will delve deeper into the science behind why the sky is blue.

Why is sky blue – What light is made of ?

The first thing to understand is that light is made up of electromagnetic waves, which are categorized by their wavelength.

Visible light, the type of light that we can see with our eyes, has wavelengths between 400 and 700 nanometers (nm).

Each color of visible light corresponds to a different wavelength, with blue light having a wavelength of around 400-500 nm.

What happend when light enters atmosphere ?

Now, let’s consider what happens when sunlight enters the Earth’s atmosphere. The atmosphere is composed of a mixture of gases, including nitrogen, oxygen, and trace amounts of other gases.

When sunlight enters the atmosphere, it collides with these gas molecules. This collision causes the light to scatter in all directions. This is known as Rayleigh scattering.

The key thing to note here is that the amount of scattering that occurs depends on the wavelength of the light.

Shorter wavelengths (such as blue light) are scattered more than longer wavelengths (such as red light).

This is because the gas molecules in the atmosphere are closer in size to the wavelength of blue light, so they are more effective at scattering it.

As a result, when sunlight enters the atmosphere, the blue light is scattered in all directions.

This means that as you look up at the sky, you are seeing blue light that has been scattered in all directions by the atmosphere.

This is why the sky appears blue.

Why is sky blue – Well what else to note?

It’s worth noting that the sky doesn’t always appear blue. During sunrise and sunset, for example, the sky often takes on a reddish-orange hue.

This is because at those times of day, the sunlight has to travel through more of the Earth’s atmosphere before it reaches us.

This causes even more scattering, which means that the longer wavelengths (such as red and orange) are scattered more than the shorter wavelengths (such as blue).

As a result, the sky takes on a reddish-orange color.

Another factor that can affect the color of the sky is air pollution. When there are high levels of particulate matter in the air (such as smoke or haze), this can also affect the scattering of light.

In polluted areas, the sky may appear more gray than blue.

In conclusion, the reason why the sky appears blue is due to Rayleigh scattering, a phenomenon in which the shorter wavelength of blue light is scattered more than the longer wavelengths of red and orange light.

This scattering causes the blue light to be scattered in all directions, giving the sky its distinctive blue hue.

While it may seem like a simple question, the answer is actually a fascinating example of the interplay between physics and atmospheric chemistry.

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Hello Friends, my name is Sanjeev Kumar. I am from Kanpur and I have been in the industry of education, training and mentoring for 20 years now. I love imparting what I have learnt and sharing my knowledge. I hope my articles benefit you. On this website you will also find information regarding goverment jobs, goverment schemes , various scholorships , etc. Hope you find all these information helpful! You can write to me at skumar@indiacareeradvice.com

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