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
A-sound featured two bonus live cuts. Later in 2009, A-Sound began recording a follow up album, but after becoming unsatisfied with the results, scrapped it. A-Sound covered a song from The Beatles. A-sound A-sound is a Mongolian indie rock band. They have had success in Mongolia with songs and albums released in both Mongolian and English versions. Their single "Release" was number one on the Mongolian chart for nine weeks. "A-sound " with five members (Lead Vocalist, Pianist, Bass Guitarist, Drummer, Solo Guitarist ). Before the band gathered they used to play separately. In 2006 all members decided to become band