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carter7gindenv
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- TL;DR Summary
- Why does a black body spectral intensity is bellshaped if it's absorptance equal 1?
This bother me too much.
A black body is said to absorb every incoming radiation.
Looking at absorptance we have :
A=Φabs/Φreceived
So if a Black body absorbs everything we have A=1
Φ is a flux meaning object/time.
This means that whatever the wavelength a black body will absorb the maximal flux.
However the spectre of a black body intensity is bellshaped meaning that the emitted flux is higher at some wavelength.
Therefor it would mean that the absorptance should not be A=1 whatever the wavelength thus contradicting the fact that a black body absorbs every incoming radiation.
I believe I'm thinking in circle there. Save me please.
EDIT: Maybe I'm confusing Absorptance/absorptivity and Emittence/emissivity.
Half the question about that says it is the same thing and the other half that it isn't. I really can't tell and I'm hungry.
A black body is said to absorb every incoming radiation.
Looking at absorptance we have :
A=Φabs/Φreceived
So if a Black body absorbs everything we have A=1
Φ is a flux meaning object/time.
This means that whatever the wavelength a black body will absorb the maximal flux.
However the spectre of a black body intensity is bellshaped meaning that the emitted flux is higher at some wavelength.
Therefor it would mean that the absorptance should not be A=1 whatever the wavelength thus contradicting the fact that a black body absorbs every incoming radiation.
I believe I'm thinking in circle there. Save me please.
EDIT: Maybe I'm confusing Absorptance/absorptivity and Emittence/emissivity.
Half the question about that says it is the same thing and the other half that it isn't. I really can't tell and I'm hungry.
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