Splitting sunbeams and making rainbows

Back to our wonderful book of Science Experiments this afternoon and after our first failure (making a spectroscope from a recordable cd - it said the coating would come of easily with packing tape but it didn't seem to come off at all!), K chose to split a sunbeam instead.
It's very simple you need a straight sided glass of water, white card, black card, scissors/craft knife and a sunny day (or a torch!).  Cut a narrow slit in the black card, then stand the glass on the white paper, lean the black card against the glass and in our case wait for the cloud to pass to see the results.


The whole set up.

The close up - you can just about see the spectrum just below/to the left of the fold of the card.

That was 'quite interesting' and we had a look at the explanation about different wave lengths, refraction and so on.  Then, with the same idea but different method, we had some squirty fun making rainbows!  The only thing you need is a water sprayer and of course the sun.  Set it to the mistiest setting and get squirting.

You can just about see the rainbow to the right of K's hands there.

I think this one's a bit clearer.