We all know what a tenth of a second feels like. It’s a jiffy, a snap of the fingers, or a camera shutter click. But what does 14 billion years, which is the age of the universe, feel like?
JILA’s atomic clock has the precision to measure the age of the universe to within a tenth of a second. That sort of precision is difficult to intuit. Yet JILA’s atomic clock, which is the most...