Super clock sets new standard for time-keeping

The world's ultimate timepiece is not a gold Rolex or diamond-encrusted Patek Philippe, but a so-called optical lattice clock, which passed a key accuracy test this week and is being touted as the time-measuring device of the future.

Physicists said the test result boosts chances that the world's timekeepers will adopt it for defining the second, making it the clock by which all other timepieces will literally be measured.

Atomic clocks, of which the optical lattice clock is the latest improvement, were first introduced in 1955.

Current varieties measure time by using microwaves to track the very regular, and very fast "vibrations" of atoms as they transit between two energy levels.

The high accuracy of these clocks lies behind the success of such technology as the Global Positioning System (GPS), which requires orbiting satellites to be synchronised so that their signals, received on Earth's surface, can be triangulated to give the receiver's location.

Impressive as current atomic clocks are, they can -- in theory -- be outperformed by clocks based on lasers, like the optical lattice clock.

The "tick" of an atomic pendulum is something that occurs trillions of times every second ... if you can measure it.