Rainbow in a Jar
How many times have you peeked out the window on a rainy day and seen a rainbow (or two)? Rainbows usually only appear after the rain because the sun's rays bounce off the drops remaining in the atmosphere. As they do, they split into all the colors of the rainbow.
This resembles what you see when you shine light through a prism. The glass splits the white light up into its different frequencies.
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