Crust (geology) Crust (geology) In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle). The crusts of Earth, Moon, Mercury, Venus, Mars, Io, and other planetary bodies formed via igneous processes, and were later modified by erosion, impact cratering, volcanism, and sedimentation. Most terrestrial planets have fairly uniform crusts. Earth, however, has two distinct types: continental crust and oceanic crust. These two
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