angle of reflection
zâviye-ye bâztâb (#)
Fr.: angle de réflexion
The angle between the reflected ray and the normal to the reflecting surface.
→ angle; → reflection.
Fr.: réflexion diffuse
Reflection of light from a rough or granular surface, which takes place in all directions due to the microscopic irregularities of the interface; opposed to → specular reflection.
→ diffuse; → reflection.
law of reflection
qânun-e bâztâb (#)
Fr.: loi de réflexion
One of the two laws governing reflection of light from a surface: a) The → incident ray, normal to surface, and reflected ray lie in the same plane. b) The → angle of incidence (with the normal to the surface) is equal to the → angle of reflection.
→ law; → reflection.
The return of radiation after striking a surface, without change in wavelength. If the surface is smooth, reflection is regular, otherwise it is diffuse. → diffuse reflection; → specular reflection.
Verbal noun of → reflect.
hamgar-e bâztâb (#)
Fr.: coefficient de réflexion
The ratio given by the → amplitude (or energy) of a reflected wave divided by the amplitude (or energy) of the incident wave.
→ reflection; → coefficient.
Fr.: facteur de réflexion
The ratio of total flux that is reflected from a surface to the incident flux. Also called reflectance, reflectivity.
→ reflection; → factor.
Fr.: nébuleuse par réflexion
A type of nebula that is visible from its reflection of starlight. Bright stars near reflection nebulae emit light into the region that is reflected by the large amount of dust there. The size of the dust grains causes blue light to be reflected more efficiently than red light, so these reflection nebulae frequently appear blue in color.
→ reflection; → nebula.
Fr.: réflexion régulière
The reflection of light when the reflecting surface is very smooth and the reflected rays bounce off parallel to each other. Opposite of → diffuse reflection; same as → specular reflection.
→ regular; → reflection.
bâztâb-e âyenevâr (#)
Fr.: réflexion spéculaire
The reflection of light waves in which the reflected waves travel in a definite direction, and the directions of the incident and reflected waves make equal angles with a line perpendicular to the reflecting surface. Same as → regular reflection; opposite of → diffuse reflection.
From L. specularis, from speculum "mirror;" → reflection.
Bâztâb, → reflection; âyenevâr "mirror-like," from âyené, → mirror + -vâr similarity suffix.
total internal reflection
bâztâb-e hamâk-e daruni
Fr.: réflexion totale interne
A phenomenon occurring when a light ray traveling cross an → interface from a higher → refractive index medium to a lower refractive index medium hits the interface at an angle larger than the → critical angle. In these conditions the light will not pass through to the second → medium at all. Instead, all of it will be reflected back into the first medium.
→ total; → internal; → reflection.