If water had its way, if geology stopped, the seas would chew up the continents, and rain would wear down the mountains. Water would eventually scour the entire planet into a smooth, definitionless sphere. We’d be left with a single ocean, waist deep, all over the globe. Then, with nothing left to throw itself at, all the divisions and obstacles eroded - no unworn pebbles, no beaches to crash into, every water molecule touching another - water would disclose, finally, what was in its molecular heart. Would it stand calm and unruffled? Or would it turn on itself - would it throw itself up into storms?
Anthony Doerr, in About Grace, 2005.  (via fatchance)