JILA physicists have measured Albert Einstein’s theory of general relativity, or more specifically, the effect called time dilation, at the smallest scale ever, showing that two tiny atomic clocks, separated by just a millimeter or the width of a sharp pencil tip, tick at different rates.
The experiments, described in the Feb. 17 issue of Nature, suggest how to make atomic clocks 50 times more precise than today’s best designs and offer a route to perhaps revealing how relativity and gravity interact with quantum mechanics, a major quandary in physics.