heijastussääntö

Heijastussääntö, or the law of reflection, is a fundamental principle in optics that describes how light behaves when it strikes a surface. It states that the angle of incidence is equal to the angle of reflection. The angle of incidence is the angle between the incoming light ray and the normal to the surface at the point of incidence. The normal is a line perpendicular to the surface. The angle of reflection is the angle between the reflected light ray and the same normal.

Furthermore, the law of reflection also dictates that the incident ray, the reflected ray, and the normal all lie in the same plane. This means that the light does not bounce off at an arbitrary angle but rather in a predictable manner. This principle is crucial for understanding how mirrors form images, how light travels through optical instruments like telescopes and microscopes, and even how we perceive objects in our everyday environment. Without the heijastussääntö, the formation of clear and recognizable reflections would not be possible. It applies to smooth, specular surfaces where light reflects coherently, as opposed to diffuse reflection from rough surfaces where light scatters in many directions.