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
The Dog and Its Reflection The Dog and Its Reflection The Dog and its Reflection (or 'Shadow' in several translations) is one of Aesop's Fables and is numbered 133 in the Perry Index. An indication of how old and well-known this story was is given by an allusion to it in the work of the philosopher Democritus from the 5th century BCE. Discussing the foolish desire for more, rather than being content with what one has, he describes it as being 'like the dog in Aesop's fable.' In the story, a dog that is carrying a stolen bone, or piece of meat or cheese, looks