Help me explain light waves to my 4 year old

[reikizen]

What answers have you all given to that age old question 'why is the sky blue?'. I've googled it but the answers are way to complicated for a 4 year old.

Think I'd go for saying it was 'like' a tinted lens - like sunglasses but blue. You might even have some blue plastic/cellophone you can hold up and look through. I don't think you'll get any closer at 4.

There is the age old method for dealing with tricky questions.

"ohh look what I have in my other hand! is it a sweetie!... ohh it is a sweetie!"

How about sunglasses as an analogy?

That's something he's probably familiar with? Can you explain that the sunglasses absorb certain light which changes the colour?

Can't think of a better example off the top of my head....

Or a rainbow - that might be a good way to introduce the concept of light to a 4 YO

Rofl @ Greyriverside

Sorry Greyriverside - would help if I read your post first!

White light is really made up of lots of different colours; it just looks white when they are all mixed up together (rainbow may be a good concept to bring in here). The sky looks blue because when the light from the sun gets to the Earth little bits of dust and water in the air scatter the blue light more than the other colours, so you see lots of blue light.

That's great, she looked absolutely fascinated by the rainbow explanation, as did her 39 YO father!

The sky's blueness is nothing to do with bits of dust and water, contrary to the explanation given in most school physics lessons. The sky looks blue because you are looking through a great thickness of air illuminated by the sun - and air is blue!

We don't normally think of air as being blue, but in sufficient amounts we can see the blue colour. It's similar to looking at a sheet of glass; when you look through the glass normally it seems clear and colourless, but look at it edge-on and you can see it's green (generally).