atomic clocks tagged posts

Time is vital to the functioning of our everyday lives: from the watches on our wrists to the GPS systems in our phones. Communication systems, power grids, and financial transactions all rely on precision timing. Seconds are the vital units of measurement in timekeeping.

Surprisingly, there is still debate over the definition of the second. But recent advances in the world’s most accurate forms of timekeeping may have just changed the game.

Accurate timekeeping has always been part of humankind’s social evolution...

Atomic clocks, combined with precise astronomical measurements, have revealed that the length of a day is suddenly getting longer, and scientists don’t know why. This has critical impacts not just on our timekeeping, but also things like GPS and other technologies that govern our modern life.

Over the past few decades, Earth’s rotation around its axis—which determines how long a day is—has been speeding up. This trend has been making our days shorter; in fact, in June 2022 we set a record for the shortest day over the past half-century or so.

But despite this record, since 2020 that steady speedup has curiously switched to a slowdown—days are getting longer again, and the reason is so far a mystery.

While the clocks in our phones indicate there are e...

Two teams of physicists have designed the first programmable quantum sensor, and tested it in the laboratory. To do so they applied techniques from quantum information processing to a measurement problem. The innovative method promises quantum sensors whose precision reaches close to the limit set by the laws of nature.

Atomic clocks are the best sensors humankind has ever built. Today, they can be found in national standards institutes or satellites of navigation systems. Scientists all over the world are working to further optimize the precision of these clocks...

Transportable radio telescopes could provide global high-precision comparisons of the best atomic clocks. Using radio telescopes observing distant stars, scientists have connected optical atomic clocks on different continents...