Structure of the Earth the crust, upper mantle, lower mantle, outer core, and inner core. The geologic component layers of Earth are at the following depths below the surface: The layering of Earth has been inferred indirectly using the time of travel of refracted and reflected seismic waves created by earthquakes. The core does not allow shear waves to pass through it, while the speed of travel (seismic velocity) is different in other layers. The changes in seismic velocity between different layers causes refraction owing to Snell's law, like light bending as it passes through a prism. Likewise, reflections are caused by a large
The Public and its Problems what he saw as argumentation on the part of Lippman that was particularly doctrinaire and absolutist in its judgements, and saw his own philosophical pragmatism as a means by which a more accurate and realistic conception of what the public and democracy was capable of it, and its limitations. Dewey begins his argument by distinguishing between the "state," represented by elected lawmakers, and the "public," the diffuse, often incoherent body of citizens who elect the state. The public is called into being when ordinary citizens experience the negative externalities (or consequences) of exchanges beyond their control (such as market or