Scientists Build a Better Clock—With Lasers One step closer to clock that could redefine the second By Ruth Brown, Newser Staff Posted Jul 10, 2013 2:22 AM CDT 9 comments Comments (Shutterstock) (Newser) – Scientists are one step closer to officially replacing those clunky old atomic clocks (accurate to one second every 100 million years—how did we even put up with such vagueness for so long?) with cutting-edge optical lattice clocks (accurate to one second every 300 million years—finally!), the BBC reports. The atomic clock, by which we currently set our watches, uses the vibrations of atoms to measure time, where optical lattice clocks measure the oscillations of lasers, which operate at 40,000 times the frequency, the AFP reports. By dissecting each tick of the clock into even smaller intervals, scientists could redefine the second, reports Nature. Scientists have known optical lattice clocks are better for about a decade. But a new study by researchers at the Paris Observatory found that not only do the clocks keep better time than their atomic counterparts, it proved for the first time that two such clocks could remain in sync with each other. That may sound like a small feat, but demonstrating this level of accuracy and stability is important if the world's timekeepers are to eventually adopt the new clocks, Nature reports. And though the change may never be noticed by us mere mortals, the new clocks could help physicists more accurately measure things like rising sea levels, the AFP reports.