The most stable atomic clock built so far loses or gains less than one second every quintillion seconds (equal to 1018 seconds, or more than 30 billion years), which is about ten times better than the previous record.

Andrew Ludlow at the National Institute of Standards and Technology in Boulder, Colorado, and his colleagues used lasers to monitor the oscillation of energy levels in two sets of ultracold ytterbium atoms that had been trapped using magnetic fields and laser beams. The clocks ticked in sync with a stability of about one part in 1018.

Such stable clocks could benefit satellite communication and navigation, and would enable space-based tests of general relativity to be conducted about 1,000 times more precisely than with clocks available today.

Science http://doi.org/nj9 (2013)