Absorption and reflectance spectrums

AI Thread Summary
Absorption and emission spectra are closely related for a given substance, as they typically correspond to the same wavelengths. The relationship is influenced by the temperature of the medium; hotter substances emit radiation while colder ones absorb it. For opaque objects, the total light interaction can be simplified to absorption plus reflection equaling 100%, with transmission being zero. This means that the wavelengths absorbed and emitted by an object can complement each other based on its thermal state. Understanding this relationship is crucial for analyzing how materials interact with light.
hechnal
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hey,

just wondering, what's the relationship between absorption and emissions spectra (i.e. would they absorb and reflect the same wavelengths or complement wavelengths of radiation?)

thanx,

hechnal
 
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Light that strikes an object is either:
1. Absorbed
2. Reflected
or
3. Transmitted

These must all add up to 100%:

A + R + T = 100%

For opaque objects, T=0 (no transmission) and the equation simplifies somewhat.
 
hechnal said:
hey,

just wondering, what's the relationship between absorption and emissions spectra (i.e. would they absorb and reflect the same wavelengths or complement wavelengths of radiation?)

thanx,

hechnal
For a particular substance, they are the same. It depends on the temperature of the medium relative to the light coming through. Hotter leads to emission, colder leads to absorption.
 
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