What you'll need:

A glass of water (about three quarters full)
White paper
A sunny day


Instructions:

Take the glass of water and paper to a part of the room with sunlight (near a window is good).
Hold the glass of water above the paper and watch as sunlight passes through the glass of water, refracts and forms a rainbow of colors on your sheet of paper.
Try holding the glass of water at different heights and angles to see if it has a different effect.

MAKE YOUR OWN RAINBOW!