Editing Radiation pressure (section)

=== Radiation pressure from reflection ===
The above treatment for an incident wave accounts for the radiation pressure experienced by a black (totally absorbing) body. If the wave is [[specularly reflected]], then the recoil due to the reflected wave will further contribute to the radiation pressure. In the case of a perfect reflector, this pressure will be identical to the pressure caused by the incident wave:

<math display="block"> P_\text{emitted} = \frac{I_f}{c}</math>

thus ''doubling'' the net radiation pressure on the surface:

<math display="block"> P_\text{net} =   P_\text{incident} +  P_\text{emitted} = 2 \frac{I_f}{c}</math>

For a partially reflective surface, the second term must be multiplied by the reflectivity (also known as reflection coefficient of intensity), so that the increase is less than double. For a [[Diffuse reflection|diffusely reflective]] surface, the details of the reflection and geometry must be taken into account, again resulting in an increased net radiation pressure of less than double.