A wave is a uniformly propogating disturbance in a medium. Waves can be classified as either mechanical or electromagnetic. Although mechanical waves cannot transmit energy through a vacuum, electromagnetic waves are capable of self propagation and can travel through a vacuum. This distinction, however, does not prevent mechanical and electromagnetic waves from exhibiting similar behavior as they propagate through a medium. When a wave, whatever its type, travels through a medium, it can either reach the end of the medium, encounter a barrier, or transfer to another medium with different inertial (e.g., density) or elastic (e.g., bulk modulus) properties. Waves traveling through a medium exhibit wave reflection, refraction, diffraction, or interference.

Reflection occurs when a wave strikes a reflective surface. If the wave is electromagnetic, it will be partially reflected and partially transmitted as a refracted ray. In physics, the general law of reflection...