Refraction In Cloudy Water
Demonstrates how a light ray bends when it enters a different medium at an oblique angle.
Laser with plastic tank containing water with powdered creamer.
The ray from the laser refracts when entering the surface of the cloudy water. The path of the laser beam in the water is rendered more visible by adding a touch of powdered creamer to the water.
Philip DiLavore, Reflection and Refraction at an Interface, TPT 13, 247-248, (1975).