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
Do Not Ask What Good We Do the 2010 election. A majority of those he spoke with and listened to were Republicans, especially among the 87 new legislators. The title of the book, "Do Not Ask What Good We Do", is taken from a sentence in a letter from Fisher Ames to Thomas Dwight, dated May 30, 1796: "Do not ask what good we do : that is not a fair question, in these days of faction." The prologue to the book details how, on the night of Obama's inauguration, a group of around 15 Republican Representatives and Senators met in the Caucus Room, a "high-end D.C.