Mantle (geology) Mantle (geology) The mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest and most massive layer of the planetary body. Mantles are characteristic of planetary bodies that have undergone differentiation by density. All terrestrial planets (including Earth), a number of asteroids, and some planetary moons have mantles. The Earth's mantle is a layer of silicate rock between the crust and the outer core. Its mass of 4.01 × 10 kg is 67% the mass of the Earth. It has
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