Blackbody Radiation

Blackbody term denotes an ideal body which would,if it exists,absorb all and reflect none of the radiation fallin upon it;its reflectivity would be zero and its absorptivity would 100%.Such a body would,when illuminated,appear perfectly black,and would be invisible except its outline might be revealed by the obscuring of object beyond.The chief interest attached to such a body lies in the character of the radiation emitted by it when heated on the laws that govern the relations of the flux density and the spectral energy distribution of that radiation with varying temperature.