Table of Contents
Introduction
A clear, cloudless daytime sky is blue because molecules in the air scatter more blue light from the sun than red light. When we look at the sun at sunset, we see red and orange colours because blue light has been scattered out and away from our line of sight. The white light emitted by the sun is a composite of all the colours of the rainbow. Isaac Newton demonstrated this by using a prism to separate the different colours and thus form a spectrum. Light’s colours are distinguished by their different wavelengths.
The visible part of the spectrum ranges from red light at about 720 nm to violet at about 380 nm, with orange, yellow, green, blue, and indigo in between. The three types of colour receptors in the human retina respond most strongly to red, green, and blue wavelengths, providing us with colour vision. If shorter wavelengths are the most heavily scattered, why doesn’t the sky seem violet, the colour with the shortest observable wavelength?
The sun’s spectrum of light is not consistent throughout all wavelengths, and some of it is absorbed by the high atmosphere, resulting in less violet light. In addition, violet has a lower sensitivity in our eyes. That is part of the answer; however, a rainbow demonstrates that there is still a significant amount of visible light-coloured indigo and violet beyond the blue. The rest of the solution to this puzzle is found in the way our vision works. In our retina, we have three types of colour receptors or cones. That is part of the solution, but a rainbow shows that beyond the blue, there is still a large amount of visible light-colored indigo and violet.
Overview
When the air is clear, the sunset will appear yellow because the sun’s light has travelled a long distance through the air and some of the blue light has been scattered away. The sunset will be more red if the air is polluted with small particles, whether naturally or artificially. Sunsets over the sea may also be orange due to the presence of salt particles in the air, which act as Tyndall scatterers.
The sky around the sun, as well as the light coming directly from the sun, appears reddened. This is due to the fact that all light is relatively well scattered through small angles, but blue light is more likely to be scattered twice or more over longer distances, leaving the yellow, red, and orange colours. Molecules larger than the wavelength of light experience the scattering effect differently; this is known as the Mie effect. Because of the size of the particles, the light appears white.
That is why clouds, which are made of water droplets, are white. The blue colour is present in the majority of lower wavelengths. The scattering efficiency of small molecules in the atmosphere decreases as the wavelength of the light increases. The sun emits light, and its rays fall into the earth’s envelope, scattering sunlight in the atmosphere.
There are certain examples of scattering as well; particles such as dust and smoke can scatter radiation. In the same way, we can explain why the sun appears to be red. The wavelength of red light is longer, and it is easier to pass through the atmosphere because it scatters less. When light strikes another item, it is scattered according to its attributes, as different light has varied intensities and each particle has different properties.
What is the colour of sky?
The sky is blue because of a phenomenon known as Rayleigh scattering. This scattering is the scattering of electromagnetic radiation (of which light is a type) by particles with much smaller wavelengths. Sunlight is scattered by atmospheric particles, and what comes down to earth is known as diffuse sky radiation. Although only about one-third of the light is scattered, the smallest wavelengths of light tend to scatter more easily. These shorter wavelengths correspond to blue hues, which is why we see blue when we look at the sky. The angle at which sunlight enters the atmosphere changes dramatically at sunset and sunrise, and most blue and green (shorter) wavelengths of light are scattered even before reaching the lower atmosphere.
I used to believe that the ocean was blue because it reflected the sky, but that is no longer the case. Water appears blue because of its absorption of red light. When light strikes water, the water molecules absorb some of the photons. Everything absorbs at a different wavelength (your green t-shirt absorbs red), and as a result, the remaining colours are reflected back at a viewer (this is why your t-shirt appears green). Because there isn’t enough water to absorb enough photons in shallow bodies of water (like a drinking glass), light penetrates completely, and we see the water as colourless.
Sky colour
Sunlight enters the Earth’s atmosphere and is dispersed in all directions by the gases and particles in the atmosphere. Because blue light travels in shorter, smaller waves than the other colours, it is scattered more. This is why the bulk of the time we see blue skies. When white light passes through a prism, it separates into all of its colours. A prism is a crystal that has been specially shaped. If you’ve been to The Land of the Magic Windows, you’ll know that the light you see is just a speck of all the different types of light energy that are beaming around the universe—and around you.
Light energy travels in waves in the same way that energy does in the ocean. Light travels in short, “choppy” waves in some cases. Other types of light travel in long, lazy waves. The wavelengths of blue light are shorter than those of red light. Sunlight enters the Earth’s atmosphere and is dispersed in all directions by the gases and particles in the atmosphere. The tiny molecules of air in Earth’s atmosphere scatter blue light in all directions. Blue is more scattered than other colours because it travels in smaller, shorter waves. This is why we see blue skies the majority of the time.
Why is the color of sky blue?
The gases and dust particles in the atmosphere scatter sunlight that reaches the earth’s atmosphere in all directions. Because the blue colour is more scattered, the sky appears blue. The reason for more scattering of blue light is that its wavelength is shorter than that of the other light. As a result, the tiny molecules of air in Earth’s atmosphere scatter blue light in all directions. This is why the sky appears blue. Gaseous nitrogen and oxygen are the two most common types of matter in the atmosphere.
These particles are most effective at scattering visible light at higher frequencies and shorter wavelengths. This scattering process entails the absorption of a light wave by an atom, followed by the reemission of a light wave in various directions. The amount of multidirectional scattering that occurs is proportional to the frequency of the light. As white light from the sun passes through our atmosphere, the higher frequencies are scattered by atmospheric particles, while the lower frequencies are more likely to pass through with little change in direction.
This scattering of higher-frequency light illuminates the skies with light from the BIV end of the visible spectrum. Violet light is more easily scattered by atmospheric particles than blue light. Our eyes, on the other hand, are more sensitive to light with blue frequencies. As a result, we perceive the skies to be blue.
Conclusion
As white light travels through our atmosphere, it is scattered by tiny air molecules. The wavelength of light decreases, the scattering caused by these tiny air molecules (known as Rayleigh scattering) increases. Result shows that blue light scatters more than red light, making the sky appear blue during the day. The sky is blue because of a phenomenon known as Rayleigh scattering. This scattering is the scattering of electromagnetic radiation (of which light is a type) by particles with much smaller wavelengths.
Also read: Important Topic of Physics: Wave Optics
FAQs
What causes the sky to be blue?
The sky is commonly misunderstood to be blue because it reflects the blue of the seas and oceans. In fact, our blue skies are caused by the Earth's atmosphere and a process known as scattering.'
On a clear day, why does the sky appear blue?
Image result for faqs about the blue colour of the sky. A clear, cloudless daytime sky is blue because molecules in the air scatter more blue light from the sun than red light. When we look at the sun at sunset, we see red and orange colours because blue light has been scattered out and away from our line of sight.
What causes the sky to appear blue in Color?
The sky is blue because of a phenomenon known as Rayleigh scattering. This scattering is the scattering of electromagnetic radiation (of which light is a type) by particles with much smaller wavelengths.
