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
Sound of a Woman fun this sound was -- and is." Julia Leconte of "NOW Magazine" noticed that "at first, [...] Kiesza's debut album seems overwrought [...] but eventually, subtleties and variety emerge" and felt that "Kiesza's so much better when she reels back her impressively ranging vocals to buttery." Chris Chiu of "The Silhouette" wrote that the album "offers the same intensity and sound that made her an instant hit and proved her overwhelming potential," but also that it "suffers from a bit of an identity crisis." Larry Fitzmaurice of Pitchfork Media noted that "Sound of a Woman" "fails to spark, as its