In the Sunda Strait, where geological memory runs deep, Anak Krakatau reminded the modern world on Sunday that the earth's interior operates on its own schedule. A 30-second eruption sent twin ash columns tens of thousands of feet into the atmosphere, closing eight airports, canceling more than 1,500 flights, and leaving 170,000 passengers across Indonesia to reckon with the limits of human planning. No lives were lost, but the disruption — spreading from Jakarta's runways to schoolrooms to the open waters of the Indian Ocean — offered a quiet lesson in the enduring power of natural forces to