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
Not a Damn Thing Changed tribute to one of the guys I grew up with who hung himself in January. He was three months older than me and we walked through life together." A music video to accompany the release of "Not a Damn Thing Changed" was first released on YouTube on 11 October 2018 at a total length of three minutes and forty-nine seconds. The video was directed by René Sascha Johannsen. Forchhammer's real-life childhood friends appear in the video, which they filmed in Copenhagen and their hometown, Christiania. Not a Damn Thing Changed "Not a Damn Thing Changed" is a song by Danish