Christmas candy cane optical illusion?

Can you slice a candy cane in half without touching it?

What you need:

• clear glass
• candy cane or candy stick
• water
• oil

What to do:

1. Pour water into the glass.
2. Pour oil into the glass to make layer about 1 inch deep.
3. Put the candy cane in the glass and rotate it. When you turn it, does the candy cane seem to come apart?

What's happening:
Water, oil, and air each slow down light a little bit differently. This means that the light bends a little bit where the air meets the oil, and where the oil meets the water. The result? A candy cane that looks chainsawed into segments.

From the book Candy Experiments 2 by Loralee Leavitt