Task: Text Categorization
Input (English): The radiation per unit solid angle of a wave undergoing this process varies with the cosine of the angle between the line of sight and the perpendicular. Lambert's emission law applies to the directionally independent form of this process, in which a microscopically rough interface causes it to occur in many different angles in the "diffuse" type of this phenomenon. The "specular" variety of this process is modeled by a law which states that the angle of incidence equals this process's namesake angle. For 10 points, name this optical phenomenon in which a wavefront rebounds off of a surface, often facilitated by mirrors.
Output (English): Science