Blue Sky - Why Not a Red Sky?

Colors of the Rainbow

A common question every parent and teacher has heard from children at some point — Why is the sky blue?

Learning the correct answer is important. Because once children hear an answer several times, right or wrong, this answer becomes embedded in their brain.

Convincing them otherwise, especially if they learned the wrong answer, takes a lot of evidence to undo this misconception.

Why the Sky is Blue? - Common Answers

Children come up with a variety of answers when asked why the sky is blue.

Their answers reflect what they hear from peers, parents, and movies or television.

Here are a few common answers children give:

• The sunlight reflects off the oceans.
• The sky is blue because it is the bottom of space.
• Because of all the water in the sky.
• The sky reflects off the top of clouds which contain water.

The sky appears blue because the molecules of air in the upper atmosphere scatter the blue waves of light more than the other colors as sunlight passes.

This answer will illicit another response from children –- But light is clear because you do not look blue!

It is true light is clear, because of all the colors which make up sunlight. At this point, children will want proof.

This can be proved by using a prism to separate the clear sunlight into the colors of the rainbow – ROYGBIV.

Connecting the prism and wavelengths is important to understanding why the sky is blue.

Children need this evidence to support internalization of the new information they just learned about sunlight and why the sky is blue.

You may have probably predicted the next question children will ask.

This question is — Why isn’t the sky red, yellow, orange, green, etc.?

This is typical and expected from children who are now questioning the evidence being presented to them. They are conducting inquiry-based science.

Additional Resource

For more about inquiry-based science visit Understanding Science Inquiry.