Humans are fleeting visitors on this roiling rock in the universe. On December 26, 2004, at 58 minutes and 49 seconds past midnight GMT, Mother Earth reacquainted us with this immutable fact. For millions of years, a creeping slab of Earth´s crust--the India Plate--had been grinding headlong into a similarly stubborn chunk of rock called the Burma Plate. Like a clash of Brobdingnagian armies, millennia of pent-up kinetic energy suddenly exploded from the seabed, a scant 100 miles from Sumatra, Indonesia. The ensuing force--equal to 25,000 Nagasaki-size atomic bombs detonated in tandem-- jolted the Earth from its axis, permanently shortened the length of the day, and hurled walls of seawater onto thousands of miles of coastline--from the Andaman to the Arabian--sweeping away at least 200,000 lives in an instant. What´s most terrifying about the recent tsunami is that a repeat performance is virtually guaranteed. Earth, by its very nature, is a prolific architect of mayhem and purveyor of calamity. The only thing we can do to protect ourselves is strive to learn where and when such massive natural disasters will happen--because rest assured, they will happen.