Ask A Scientist© Physics Archive

Question:  What is a "Blackbody" in terms of Blackbody radiation, the
Compton Effect, etc? Thanks.
Adam Beauregard

Answer:  I do not think the Compton effect has anything to do
with black bodies - you may be reading about Compton
radiation and black body radiation in some context
in astronomy though? A "blackbody" is a perfect
absorber and radiator (it turns out absorption and
radiation are intimately connected) - for example the
...  well there are no exact examples...
Anyway, the radiation from a blackbody was calculated
early in this century and it depends only on the temperature
of the body (and the surface area from which the radiation
is coming) - the electromagnetic energy radiated has a peak
at a frequency that increases as the temperature increases, and
the total amount of energy radiated goes as the fourth power
of the temperature.  When something is very hot, it glows
at visible wavelengths (a few thousand degrees) or
even ultraviolet light (tens of thousands of degrees)
or X-rays (even hotter...) but ordinary objects do not
quite match the black body spectrum because of characteristic
features in their absorption.
Compton radiation comes when electrons are diverted by coming
close to atomic nuclei and send of bursts of light.
Arthur Smith