1. Do this experiment in a dark room to achieve much better results. 2. Cut a narrow slit at one end of the shoe box using sharp scissors. 3. Fill the jar with water. 4. Place the flat-sided jar of water in the shoe box. Position the jar at an angle near the slit. 5. Place the flashlight/torch up against the slit so that the beam of light goes straight through to the jar of water.
How it happens?
Light moves slower through water than it moves through air. When the light goes through the water, it slows down and bends. As the light re-enters the air, the beam of light speeds up again and bends back. This is called refraction.