Eureka! Zientzia Museoa

This guide to the Eureka! Zientzia Museoa in San Sebastian opens with Leon Foucault, a former medical student turned photographer, who at thirty-two summoned Paris's finest scientists with four words: come see the earth turn. In February 1851 he hung a pendulum at the Paris Observatory, then took the experiment public inside the Pantheon with a sixty-one-pound brass bob on a cable over two hundred feet long, tracing shifting lines through a ring of sand below. That same pendulum now hangs inside a fourteen-meter glass tower here, moved by nothing but gravity and the cable above it.