Structure of the Earth Structure of the Earth The internal structure of the Earth is layered in spherical shells: an outer silicate solid crust, a highly viscous asthenosphere and mantle, a liquid outer core that is much less viscous than the mantle, and a solid inner core. Scientific understanding of the internal structure of the Earth is based on observations of topography and bathymetry, observations of rock in outcrop, samples brought to the surface from greater depths by volcanoes or volcanic activity, analysis of the seismic waves that pass through the Earth, measurements of the gravitational and magnetic fields of the Earth, and experiments
What Shall We Do Now? What Shall We Do Now? "What Shall We Do Now?" (working title "Backs to the Wall") is a song by Pink Floyd, written by Roger Waters. It was originally intended to be on their 1979 album "The Wall", and appeared in demo versions of "The Wall", but was omitted due to the time restraints of the vinyl format. In its place is a much shorter song, titled "Empty Spaces", which segues directly into "Young Lust". This was a last-minute decision; the album's sleeve notes still feature the song in its track listing, and include its lyrics. The beginning of the