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 Sound of a Woman Sound of a Woman is the major label debut studio album by Canadian recording artist Kiesza. It is her second album after her 2008 self-titled independent release and her first full-length international debut. It was released on 17 October 2014. In February 2014 Kiesza released the video for her new single "Hideaway" through the indie label "Lokal Legend". "Idolator" considered it unique, for having a single take through the entire video, as Kiesza walked and danced through the streets of Brooklyn. John Gentile of "Rolling Stone" called the style "impressive". Kiesza reported to "Rolling Stone" that