New clock would stay accurate for billions of years

Posted by Kate Taylor

A proposed new time-keeping system could make atomic clocks look positively erratic, staying accurate to one twentieth of a second over 14 billion years - the age of the universe.

"This is nearly 100 times more accurate than the best atomic clocks we have now," says professor Victor Flambaum of the University of New South Wales.

"It would allow scientists to test fundamental physical theories at unprecedented levels of precision and provide an unmatched tool for applied physics research."

With its time-keeping system tied to the orbiting of a neutron around an atomic nucleus, the team's proposed single-ion clock would be accurate to 19 decimal places.

Currently, atomic clocks are the standard, and are widely used in applications ranging from GPS navigation systems and high-bandwidth data transfer to tests of fundamental physics and system synchronization in particle accelerators.

Atomic clocks use the orbiting electrons of an atom as the clock pendulum. But, says Flambaum, using lasers to orient the electrons in a very specific way allows the orbiting neutron of an atomic nucleus to be used as the clock pendulum, making a so-called nuclear clock with unparalleled accuracy.

Because the neutron's held so tightly to the nucleus, its oscillation rate is almost completely unaffected by any external perturbations - unlike those of an atomic clock’s electrons, which are much more loosely bound.  

"With these clocks currently pushing up against significant accuracy limitations, a next-generation system is desired to explore the realms of extreme measurement precision and further diversified applications unreachable by atomic clocks," says Flambaum.