Kirchhoff's law of thermal radiation rarefied material such as air, or transparent material, through which observations can be made. The interface is not a material body and can neither emit nor absorb. It is a mathematical surface belonging jointly to the two media that touch it. It is the site of refraction of radiation that penetrates it and of reflection of radiation that does not. As such it obeys the Helmholtz reciprocity principle. The opaque body is considered to have a material interior that absorbs all and scatters or transmits none of the radiation that reaches it through refraction at the interface. In this sense
I Changed a Lot of HipHopDX said, ""I Changed A Lot" lacks a “We Taking Over”-style smash single to show for the incredible hit-making power of the performers present. Something just feels off in Khaled's traditional manner of creating ubiquitous pop cultural touchstones. This album is generally solid, but in lacking the groundbreaking moment we’ve come to expect from the artist/producer/chicken wing restaurateur known for being “the best,” it falls short." The album debuted at number 12 on the "Billboard" 200, with 25,000 equivalent album units in the United States, with 19,000 copies sold in its first week. I Changed a Lot I Changed