Perfect for Index of Refraction and Total Internal Reflection experiments.
The bending of light as it passes from one substance to another is called refraction. Refraction causes the familiar mirage as we appear to see a nonexistent pool of water on a distant road on a very hot day. The ray of light can be totally reflected back inside the cube, leading to total internal reflection, not refraction.
These and other phenomena can be studied with our Refraction Cube. The index of refraction is about 1.5, meaning that the light travels 50% faster in air than it does upon entering the acrylic plastic. Faces are 5 cm square, instructions included.