Structure of the Earth easily than does the upper mantle (chemical changes within the mantle may also be important). The viscosity of the mantle ranges between 10 and 10 Pa·s, depending on depth. In comparison, the viscosity of water is approximately 10 Pa·s and that of pitch is 10 Pa·s. The source of heat that drives plate tectonics is the primordial heat left over from the planet’s formation as well as the radioactive decay of uranium, thorium, and potassium in Earth’s crust and mantle. The average density of Earth is . Because the average density of surface material is only around , we must
What We Do Is Secret (novel) What We Do Is Secret (novel) What We Do Is Secret is a novel by Thorn Kief Hillsbery, published by Villard in 2005. "What We Do Is Secret" takes place in Los Angeles in 1981, six months after the death of Darby Crash (lead singer of the Germs). It is narrated by a gay street kid named Rockets Redglare, who knew Darby personally. All the action occurs over the course of 24 hours, on Rockets' 13th birthday. Rockets was ten years old when he first met Darby Crash, lead singer of LA punk band the Germs. He and Darby had