A nuclear clock proposed by researchers from the University of New South Wales could be accurate to a twentieth of a second over 14 billion years, or around the life of the universe so far. While atomic clocks rely on orbiting electrons as their pendulum, the researchers say that the best clocks in use today are around 100 times less accurate than a nuclear one would be.
Professor Victor Flambaum, leading the research, explains that, "by using lasers to orient the electrons in a very specific way, one can use the orbiting neutron of an atomic nucleus as the clock pendulum, making a so-called nuclear clock with unparalleled accuracy." Since the neutron orbits so closely to the nucleus, it is less susceptible to external interference than electrons and so orbits at a far more reliable rate.
The team behind the research sees the development of new measurement systems as desirable to continue to "explore the realms of extreme measurement precision and further diversified applications unreachable by atomic clocks.” It's not clear just yet if or when the researchers plan to construct such a clock, but their findings are set to be published in the industry journal Physical Review Letters soon.