Questions Kids Ask: Why is the sky blue?


blue-sky-clouds.jpgI’ve been thinking about questions for a while both on this blog and elsewhere.

I love asking our boys questions and I love engaging with their questions.  Like most kids, they ask great questions and crazy questions in almost equal amounts.  I love giving them answers that are age appropriate, enjoying the challenge of simplifying complex knowledge to make it understandable.


To help me with this (and maybe you?), I’ve started to develop a series of YouTube videos to accompany my explanations.  I’ll be working on these questions over the coming months and am always excited to get more ideas.  I have questions from our boys but there are probably questions that they are not asking yet, so please share your questions with me in any way you like :).

Why is the sky blue?

This is a question I get asked quite regularly.  We’re getting close to Son1 being able to understand it but we’re still not quite there.

Things you need to know to understand this:

  • Light is not one solid colour;
  • When light hits different mediums it scatters;
  • In different circumstances, some light scatters more than others.

I’ve tried to explain those things in the video but explanations are better understood when we can engage with them.  I want our kids to do something to explore their knowledge rather than passively accept answers (even if they do come with cool animated videos).

Experiment: Splitting ‘single’ colour light into lots of colours

So, I wanted to design a simple experiment for my kids to have a go at.  I want them to see that they could shine light that seems to be a single colour and see that it’s made up of the whole spectrum.


  • A mirror
  • A light source
  • A shallow dish with some water
  • A piece of paper

Set-up (loving my amazing drawing skills):


As the light from the torch passes through the water and bounces off the mirror, it splits into the colours of the rainbow.

We also played a little with this prism and saw we could let sunlight pass through and see it split into the colours of the spectrum.  I didn’t want to use the sun with the mirror experiment in case our boys looked too directly into the sun but it would work in the same way.

What next?

Where would you take this next?  What questions might your kids ask as you play with these things?

Let me know if you enjoyed this and please share any ideas you might have.  I was asked the other day, ‘How do you make sand?’ and I think that might be next.



15 thoughts on “Questions Kids Ask: Why is the sky blue?”

  1. Great idea, I love all their questions – even if I do have to look up the answers sometimes! I hadn’t thought of the water experiment before, will have to borrow that one.

  2. Thank goodness my daughter hasn’t asked this yet. If she does, I’ll know what to answer 😉 I had a younger brother though who used to ask all kinds of Science questions, thank goodness, my dad had the knowledge to answer all of them 🙂

  3. This is amazing! My little guy asked me this the other day, we will have to do this together. I love the quote too! The amount of times I think I understand something until they expect me to explain and I can’t is amazing

  4. Great idea and i love it when the kids ask questions i dont know the answers too as we get to find out together!

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