Editing Reflection (physics) (section)

===Diffuse reflection===
[[Image:Diffuse refl.gif|thumb|right|General scattering mechanism which gives [[diffuse reflection]] by a solid surface]]
{{Main|Diffuse reflection}}
When light strikes the surface of a (non-metallic) material it bounces off in all directions due to multiple reflections by the microscopic irregularities ''inside'' the material (e.g. the [[grain boundaries]] of a [[polycrystalline]] material, or the [[Cell (biology)|cell]] or [[fiber]] boundaries of an organic material) and by its surface, if it is rough. Thus, an 'image' is not formed. This is called ''[[diffuse reflection]]''. The exact form of the reflection depends on the structure of the material. One common model for diffuse reflection is [[Lambertian reflectance]], in which the light is reflected with equal [[luminance]] (in photometry) or [[radiance]] (in radiometry) in all directions, as defined by [[Lambert's cosine law]].

The light sent to our eyes by most of the objects we see is due to diffuse reflection from their surface, so that this is our primary mechanism of physical observation.<ref name="y">{{cite journal
|author=Mandelstam, L.I.
|title=Light Scattering by Inhomogeneous Media
|journal=Zh. Russ. Fiz-Khim. Ova.
|volume=58
|page=381
|year=1926
}}</ref>