Structure of the Earth decay of radioactive elements, and freezing of the inner core. 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 Social Conquest of Earth New York Times Book Review" 100 Notable Books of the Year in 2012. The Social Conquest of Earth The Social Conquest of Earth is a 2012 non-fiction book by biologist Edward O. Wilson. Wilson adapted the title of Paul Gauguin's famous mural as a theme -- "What are we?", "Where did we come from?", "Where are we going?"—for discussing his topic of eusocial behavior in several arthropod taxa and a few mammalian species, and its role in making humans as a species unique. Wilson argues, building on the paper "The evolution of eusociality" (2010) by Wilson, Martin Nowak and Corina