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 Public and its Problems The Public and its Problems The Public and its Problems is a 1927 book by American philosopher John Dewey. In his first major work on political philosophy, Dewey explores the viability and creation of a genuinely democratic society in the face of the major technological and social changes of the 20th century, and seeks to better define what both the 'public' and the 'state' constitutes, how they are created, and their major weaknesses in understanding and propagating its own interests and the public good. Dewey rejects a then popular notion of political technocracy as an alternative system of governing an