Why is sky blue?

Why are clouds white?

Why is sunrise red?

Why? Why? Why?

Experiment Video:

Unlocking the mystery, on why the sky is blue in color? why are the clouds white in color? and why is it so reddish while sunrise?  Ever wondered why? And wanted to know, then come on.


Howdy, young scientist!  Have you enjoyed today’s video?
Today is the field day in our lab. We know that your scientist has worked hard so far. So its time for a short commercial break.
Feeling curious! Then its time for your jacket for a change. In your very own eyes experience the blue sky, white clouds, and sunrise.
As you know, scientist always keeps a record even on vacation. 
To help you with this, feel free to use the following freebie.
Blue Sky, White Clouds & Red Sunset – Experiment (Free Download)


Basics before we continue further:

  • First of all from where we get the light?  Sun right!

  • Sunlight consists of 7 colors, which we see in Rainbow. 

  • All these 7 colors pass in different wave patterns.


sunlight wavelengthFewer waves = Less scattered

 More waves = More scattered

Sun emits less Indigo and Violet colors

Why is sky blue?

  • Light from the sun enters our atmosphere and bounces between the various items in the air, like nitrogen, oxygen, water droplets, dust, etc.

  • Blue color has more waves, so get scattered more than other colors like red, orange, yellow and green.

  • You may ask why not Indigo and Violet.

    • Sun emits less Violet and Indigo colors.

    • Our eyes, naturally respond more to RBG(Red, Blue, Green) colors.

Why are clouds white?

  • Let us get straight to basics, if all the sunlight colors are mixed together we get the white color.

  • Actually, Sun is not yellow or red or neither orange in color, Sun is colorless. You will ask then, how come we see the yellow/reddish/orange sun. That’s a whole new subject to discuss, let us stick to today’s topic now. Will catch up on this later.

  • Clouds appear white because of the scattering of all light colors equally. The droplets in clouds are big compared to the wavelength of light, so all wavelengths scatter the same.

Why is sunset red?

  • During Sunrise/Sunset, sunlight travels straight to us, covering larger parts of the atmosphere on the way.

  • So the Green, Blue, Indigo, Violet lights which have more waves have been mostly scattered away on the way.

  • While Red, Yellow and Orange colors have fewer waves so they mostly reach us straight.

  • According to their waves, the predominant color order will be Red, next to Orange and lastly yellow.


Scientific Learning:

Why is sky blue?

Blue sky

Light from the sun is made of all the colors of the rainbow. As this light hits the particles of nitrogen and oxygen in our atmosphere, it is scattered in all directions. Blue light has a smaller wavelength than red light, so it is scattered much more than red light. When we look at the sky, we see all the places that the blue light has been scattered from.

Why are clouds white?

Rain clouds

Clouds appear white because the water droplets are much larger than the wavelengths of light. For this situation, all wavelengths of light are equally scattered in all directions.

Why is sunset red?

Clear sunrise in beach

When the Sun appears lower in the sky, the light that reaches us has already traveled through a lot more of the atmosphere. This means that a lot of the blue light has been scattered out well before the light arrives at us, so the sky appears redder.




Atmosphere: the envelope of gases surrounding the earth or another planet

Wavelength:  the distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave

Droplet:   a very small drop of a liquid

Rainbow:    an arch of colors visible in the sky

Nitrogen:  a colorless, odorless unreactive gas that forms about 78 percent of the earth’s atmosphere



  • Manipulating Light: Reflection, Refraction, and Absorption By Darlene R. Stille

  • Scholastic Learning Express L2: Time and Measurement

https://www.youtube.com/watch?v=ftB5VU64yGA                                https://www.youtube.com/watch?v=zsv7bYSrzMU


I am scientist

I am scientist is a result of small effort to make huge impact on children. To stimulate the curiosity of young scientist towards science. Each idea will start with a experiment followed by reasoning the result , scientific learning, vocabulary (recap the big words used), useful reference website and books, along with free downloadable worksheets.

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