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reflection
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reflection Two diagrams compare light reflection: the top shows blue incident and reflected rays bouncing off a smooth surface, with equal angles from the normal; the bottom shows rays scattering from a rough surface, with normals and angles marked at various points. Figure 7: The refraction and reflection of light. (Left) When light strikes the boundary between glass and air at less than the critical angle (θc), it is refracted and partially reflected; (centre) when it meets the boundary at the critical angle, it is refracted parallel to the boundary; (right) when it meets the boundary at more than the critical angle, it is reflected totally. Diagram showing several light rays striking a rough surface at different angles, with the reflected rays scattering in multiple directions, illustrating diffuse reflection. holography Figure 5: Malus' experiment. Successive reflections at two unsilvered mirror surfaces, G1 and G2 (see text). Diagram showing light from a bee reflecting off a vertical plane mirror into an observer's eye; equal angles of incidence and reflection produce a virtual bee image behind the mirror.
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reflection
reflection Indian triggerfish (Melichthys indicus) reflected in the water's surface near the Maldives in 2006.

reflection

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Two diagrams compare light reflection: the top shows blue incident and reflected rays bouncing off a smooth surface, with equal angles from the normal; the bottom shows rays scattering from a rough surface, with normals and angles marked at various points.
Reflection of lightIn the reflection of light, the angle of incidence is equal to the angle of reflection, measured from the normal (the line perpendicular to the point of impact).

reflection, abrupt change in the direction of propagation of a wave that strikes the boundary between different mediums. At least part of the oncoming wave disturbance remains in the same medium. Regular reflection, which follows a simple law, occurs at plane boundaries. The angle between the direction of motion of the oncoming wave and a perpendicular to the reflecting surface (angle of incidence) is equal to the angle between the direction of motion of the reflected wave and a perpendicular (angle of reflection). Reflection at rough, or irregular, boundaries is diffuse. The reflectivity of a surface material is the fraction of energy of the oncoming wave that is reflected by it. See also total internal reflection.

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Adam Augustyn.