The Currents of Space (1952) is a science fiction novel by the American writer Isaac Asimov. It is the second (by internal series chronology) of three books labeled the Galactic Empire series, though it was the last of the three he wrote. Each occurs after humans have settled many worlds in the galaxy — after the second wave of colonization that went beyond the Spacer worlds — and before the era of decline that was the setting for the original Foundation series.