Angle of incidence (optics)
(Redirected from
Normal incidence
)The angle of incidence, in
angle of refraction
are other angles related to beams.
In
tangent plane of the surface and another plane at right angles to the light rays.[2] This means that the illumination angle of a certain point on Earth's surface is 0° if the Sun is precisely overhead and that it is 90° at sunset or sunrise
.
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.
Grazing angle or glancing angle
When dealing with a beam that is nearly parallel to a surface, it is sometimes more useful to refer to the angle between the beam and the
complement
to the angle of incidence is called the grazing angle or glancing angle. Incidence at small grazing angles is called "grazing incidence."
Grazing incidence diffraction is used in X-ray spectroscopy and atom optics, where significant reflection can be achieved only at small values of the grazing angle. Ridged mirrors are designed to reflect atoms coming at a small grazing angle. This angle is usually measured in milliradians. In optics, there is Lloyd's mirror.
See also
- Effect of Sun angle on climate
- Illumination angle
- Phase angle (astronomy)
- Plane of incidence
- Reflection (physics)
- Refraction
- Scattering vector
- Total internal reflection
References
- ISBN 9788189411008.
- ISBN 9780123743459.
External links
- Weisstein, Eric W. "Angle of incidence". MathWorld.
- geometry : rebound on the strip billiards Flash animation
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