The "bending light" experiment demonstrates how the course of light is altered or refracted when it passes through different mediums, such as glass or water. The experiment can be set up in 5 minutes or less and requires a small box and a glass of water.
Prepare the box
Use a small box that can fully close, such as a shoebox. Cut out an opening as wide as the glass on one side. Cut out a small hole on top to look through. The box should block out most light other than what comes through the opening in the side.
Fill up a glass with water
Fill two-thirds of a clear glass with water. Place the glass in front of the opening at the side of the box.
See the light bend
Look through the hole in the top of the box. Notice the pattern of light created inside the box. Turn off the main light in the room and shine a flashlight at the glass and into the box. Look at the patterns the glass and water create. Shine the flashlight on a wall to see what the light looks like when it is not being bent. Consider looking at different ways the light bends when the glass has less water or an opaque object inside it.