If the world were reduced to the size of an apple, the crust of the earth—the solid ground and seemingly immutable mountains that we take for granted—would be thinner than the apple's skin. Below that, a seething sphere of liquid rock diabolically roiling at a searing 1,000 °C (give or take 300 °C.) In reality our "solid ground" is the pudding skin on fiery death. When it skids a tiny bit or slight wisps of nearly nothing breathe through, these are the disasters that level cities and the magically minded point to as the power of omnipotent gods.