"It starts with the earth. How can it not? Imagine the planet like a split peach, whose pit forms the core, whose flesh its mantle, and whose fuzzy skin its crust - no, that doesn't do justice to the crust, which is, after all, where all of life takes place. The earth's crust must be more like the rind of the orange, thicker and more durable, quite unlike the thin skin of a bruisable peach. Or is it? Funny, how you never think to wonder..."