Yup, our atomic timekeeping right now just ISN'T GOOD ENOUGH!
Here's how we can make it better...!
(That) frequency is used to mark out time to an accuracy of better than 1 part in 1017, or 1 second in 3 billion years.
That's pretty good, but it could be better. Infrared photons emanating from the background cause the two energy levels to shift by slightly different amounts, says Marianna Safronova at the University of Delaware. That affects the frequency of the emitted radiation to an unknown extent, adding a small uncertainty to the clock's tick.
Safronova reported this month at a conference in Baltimore, Maryland, that by combining two different mathematical approaches, she and her colleagues have now managed to calculate how much the energy gap between the two levels changes.
Using this information to correct an atomic clock could in principle increase its precision to around 4 parts in 1019, or about 1 second per 80 billion years. Such a clock could test whether the fundamental constants of nature are changing, Safronova suggests.
Super-accurate atomic clocks emerge from 'heat haze' - 5/16/2011 - Electronics Weekly