
Angle of incidence is a measure of deviation of something from "straight on", for example: * in the approach of a ray to a surface, or * the angle at which the wing or horizontal tail of an airplane is installed on the fuselage, measured relative to the axis of the fuselage. ==Optics== In geometric optics, the angle of incidence is the angle between a ray incident on a surface and the line perpendicular to the surface at the point of incidence, called the normal. The ray can be formed by any wave: optical, acoustic, microwave, Xray and so on. In the figure above, the red line representing a ray makes an angle θ with the normal (dotted line). The angle of incidence at which light is first totally internally reflected is known as the critical angle. The angle of reflection and angle of refraction are other angles related to beams. Determining the angle of reflection with respect to a planar surface is trivial, but the computation for almost any other surface is significantly more difficult. The exact solution for a sphere (which has important applications in astronomy and computer graphics) was an open problem for nearly 50 years until a closedform result was derived by mathematicians Allen R Miller and Emanuel Vegh in 1991. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Angle of incidence」の詳細全文を読む スポンサード リンク
