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
Reflections of a Sound influenced by the "De Stijl" art movement. References to other artists such as Dalí, Da Vinci, Magritte, Mondrian and Warhol are also made. Post production by Corner Post (Sydney). Australian Digital release Australian Promo CD Reflections of a Sound "Reflections of a Sound" is a song by Australian rock band Silverchair and is the fourth track on their fifth studio album "Young Modern", released in March 2007. The song was released on 14 July 2007 as the second single from that album. The single was only released in Australia in digital format and as a CD Promo. The music video