You'll need a round glass, water, paper and a marker. Draw two arrows, stand them behind the glass, and slowly pour in water. The bottom arrow flips! The water acts like a lens, crossing the light rays so the image reverses.

You'll need a clear glass, water and a straw or pencil. Lean it in a half-full glass and look from the side. It looks broken! Light slows down in water and bends as it passes into the air. Try a word on paper behind the glass, too.

You'll need a clear glass, a coin and water. Set the glass on the coin and look through the side while someone pours in water. The coin vanishes! The light bends so sharply it reflects back into the water instead of reaching your eyes.

Refraction is the bending of light as it moves from one material into another, like from air into water. Want another hands-on project? Make a balloon inflate itself with our Magic Balloon experiment!