Outer core Outer core The outer core of the Earth is a fluid layer about thick and composed of mostly iron and nickel that lies above Earth's solid inner core and below its mantle. Its outer boundary lies beneath Earth's surface. The transition between the inner core and outer core is located approximately beneath the Earth's surface. Unlike the inner core, the outer core is liquid. The inner core is also referred to as the solid core. Seismic inversions of body waves and normal modes constrain the radius of the outer core to be 3483 km with an uncertainty of 5 km,
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