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 the Bleep Do We Know!? plays the role of everywoman as she experiences her life from startlingly new and different perspectives. In the documentary segments of the film, interviewees discuss the roots and meaning of Amanda's experiences. The comments focus primarily on a single theme: "We create our own reality." The director, William Arntz, has described "What the Bleep" as a movie for the "metaphysical left". Work was split between Toronto-based Mr. X Inc., Lost Boys Studios in Vancouver, and Atomic Visual Effects in Cape Town, South Africa. The visual-effects team, led by Evan Jacobs, worked closely with the other film-makers to create visual metaphors