Deep science.(FROM THE CASTLE)

AT THE RECENT SMITHSONIAN Folklife Festival, NASA astronaut Loren Shriver was asked what struck him most about Earth from space: "When you're circling the Earth every 90 minutes, what becomes clearest is that it's mostly water; the continents look like they're floating objects." We should actually think of the oceans as the ocean, since they are one interconnected global system. The ocean is essential to all life; it shapes our climate and weather through an intricate pattern of currents and heating and cooling mechanisms that we are only now beginning to understand. But the ocean is showing alarming strains caused by pollution, overfishing, invasive species and climate …