Crust (geology) enriched compared to the underlying mantle. Although the continental crust comprises only about 0.6 weight percent of the silicate on Earth, it contains 20% to 70% of the incompatible elements. All the other constituents except water occur only in very small quantities and total less than 1%. Estimates of average density for the upper crust range between 2.69 and 2.74 g/cm and for lower crust between 3.0 and 3.25 g/cm. Earth formed approximately 4.6 billion years ago from a disk of dust and gas orbiting the newly formed Sun. It formed via accretion, where planetesimals and other smaller rocky bodies
The Public and its Problems the public and its potential. Dewey did not call for an abandonment of the public; rather, he hoped the public would regain a sense of self. The solution to this, he writes, is improved communication. Only then, with communication, will the public find itself and become a cohesive group. In addition to Dewey's proposition that the public cannot find itself because there are too many publics, he also blames the distractions of modern society. He points out that even in the past, the public has had other concerns than politics: "Political concerns have, of course, always had strong rivals". In