One way to incorporate attenuation into the mathematical description of the wave is via an absorption coefficient:
where is the absorption coefficient. The intensity in this case satisfies:
i.e.,
The absorption coefficient, in turn, is simply related to several other quantities:
- Attenuation coefficient is essentially (but not quite always) synonymous with absorption coefficient; see attenuation coefficient for details.
- Molar absorption coefficient or Molar extinction coefficient, also called molar absorptivity, is the absorption coefficient divided by molarity (and usually multiplied by ln(10), i.e., decadic); see Beer-Lambert law and molar absorptivity for details.
- Mass attenuation coefficient, also called mass extinction coefficient, is the absorption coefficient divided by density; see mass attenuation coefficient for details.
- Absorption cross section and scattering cross section are both quantitatively related to the absorption coefficient (or attenuation coefficient); see absorption cross section and scattering cross section for details.
- The absorption coefficient is also sometimes called opacity; see opacity (optics).
Read more about this topic: Mathematical Descriptions Of Opacity
Famous quotes containing the word absorption:
“The radio ... goes on early in the morning and is listened to at all hours of the day, until nine, ten and often eleven o’clock in the evening. This is certainly a sign that the grown-ups have infinite patience, but it also means that the power of absorption of their brains is pretty limited, with exceptions, of course—I don’t want to hurt anyone’s feelings. One or two news bulletins would be ample per day! But the old geese, well—I’ve said my piece!”
—Anne Frank (1929–1945)