2006-10-05 15:58:51 · 5 answers · asked by keran_guy 2 in Science & Mathematics ➔ Physics
The reflection is the result of induced radiation from accelerated charges in the mirror.
The electromagnetic field in the light applies a force to the electric charges (electrons and protons) in the mirror. Because electrons have much lower mass than protons, one can generally ignore the effect from the protons. The electrons are accelerated by the applied fields, resulting in radiated electromagnetic fields of their own in the process. In a mirror, the radiated field cancels out the incident light in the forward direction (destructive interference) but at the same time produces light which propagates (constructive interference) in the direction of the specular reflection for the mirror.
There are many variations, such as metallic mirrors, dielectric mirrors, multilayer or holographic mirrors, etc. The best methods for calculating the behavior will vary based on the constraints applied to the electrons (freely conductive, bound in atomic or molecular structures, random or periodic, etc.), but the underlying physics is the same.
Usually there are "indirect" calculation methods which take advantage of the symmetry of a geometry to simplify the calculations from the most general case. One such method commonly used is to see which mix of reflected and transmitted fields will satisfy the "boundary conditions" of the reflecting interface. For example, the boundary condition at the surface of a metallic (conductive) mirror is often taken to be that the electric field is normal to the surface. This leads to the familiar result of specular reflection where light reflects but does not penetrate the mirror.
Refraction and scatter can also be explained in a similar way. Absorption occurs when the electrons lose some or all of the imparted energy to non-radiative processes such as heat.
2006-10-05 21:04:37 · answer #1 · answered by or_try_this 3 · 2⤊ 0⤋
All materials of mass affect the wave propagation of incident light. The atomic structure of the material determines its ability to alter the direction of an incident light wave. Depending on density, the light wave may transmit, scatter, or be absorbed in the medium. Reflection is a form of specular scatter of light by a material's dense molecules. The lightwave's interaction with the material alters the direction of the incident light wave to travel in the reverse direction. This is analogous to a tidal wave bouncing off a retaining wall.
In all materials, conservation of energy states that light transmission, reflection (scatter), and absorption all sum to unity. Little to no transmission or absorption occurs in a highly polished mirror. Hence light emitting from an object specularly scatters (reflects) or bounces off the mirror.
2006-10-05 18:30:42 · answer #2 · answered by x 5 · 1⤊ 0⤋
It depends on the kind of mirror you are talking about.
2006-10-05 17:02:53 · answer #3 · answered by Anonymous · 0⤊ 1⤋
Hi. The surface is smooth and not penetrable by light, so it bounces back.
2006-10-05 16:02:57 · answer #4 · answered by Cirric 7 · 1⤊ 0⤋
Typically away from themselves.
2006-10-05 16:16:12 · answer #5 · answered by rockEsquirrel 5 · 0⤊ 1⤋