Bijunath Patla’s experiment sounds like a real bore: Gather 12 of the most accurate clocks around the world, and watch them tick. It’s like a physicist’s version of watching paint dry. Patla’s team, based at the National Institute of Standards and Technology in Boulder, Colorado, began monitoring the clocks on November 11, 1999. And they’ve kept watching for some 4.5 billion seconds—over 14 years. But their patience paid off.