10] K, the dominant thermal or blackbody radiation
can be gamma rays.
These experiments were vital to the development of blackbody radiation
science from the days long before Balfour Stewart .
The cavity is still not filled with blackbody radiation
, as the reflective term has not yet been fully driven.
The pyrometers are calibrated using a blackbody by adjusting the electrical current in the filament until the human observer cannot distinguish it from the blackbody radiation
Relative to the claim that optically thick gases  can sustain blackbody radiation
[2, 3], the arguments advanced  fail to properly address the question.
In addition, Mikron offers users of infrared thermometers, radiometers, heat flux meters, thermal imaging systems and spectrographic analyzers a full line of blackbody radiation
calibration sources, traceable to National Institute of Standards and Technology (NIST).
Thus, when a small hole is made between the two enclosures, each cavity eventually becomes filled with blackbody radiation
when thermal equilibrium is reestablished.
However, even at room temperature, a device consisting of a gold antenna coupled to a niobium detector already serves as a sensitive detector of blackbody radiation
What these seven astronomers did was to refer the motions of the local group and the refeence galaxies to the point of view of the microwave background, the three-degree blackbody radiation
that pervades the universe.
With its formulation, blackbody radiation
achieved a magical presence within every cavity.
About 20 years ago the discovery of the cosmic background of microwave radiation, which comes to us from all directions and appears to represent blackbody radiation
and condensed matter physics [15-20,25]), not by astronomy.