Scientists have built the world’s most accurate atomic clock – and it’s so precise it could redefine the second.

Experts at Singapore’s Centre for Quantum Technologies (CQT) have developed a device that can meticulously track the passage of time, down to trillionths of a second.

The researchers believe their clock, built from the element lutetium, outperforms previous record holders built from different elements.

They say their device can measure time to 19 decimal places – the lowest reported for any optical atomic clock to date.

It is so reliable that it would take more than 260billion years to lose a second.

‘I am confident that what we have now is the most accurate clock in the world,’ team leader Murray Barrett, from the National University of Singapore, said.

Atomic clocks keep time by monitoring an atomic transition, which is when one of an atom’s electrons changes energy levels.

The frequency of this transition is a fixed property of the atom. A laser is matched to this transition and the light oscillations act like a pendulum to count time.

The basic method has been in place for decades. Cesium atoms have set the global standard for time since the 1960s, and cesium atomic clocks already support the Global Positioning System (GPS) and synchronise communication and transport networks.

Elements such as ytterbium, strontium and aluminium oscillate much faster than cesium, helping them keep time more accurately and setting records.

However, the CQT team started working with lutetium over a decade ago on the hunch that it had the right properties to join the set of top–performing clocks.

To its knowledge, it is the only group working with this element for timekeeping so far.

After measuring the frequency of the lutetium clock, the scientists reported an uncertainty of 1 x 10–19, as published in the journal Nature.

Lutetium’s strong performance comes from properties of the atom. Its clock transition is hardly affected by changes in temperature or magnetic field – two variables that can throw off the frequency of other elements.

‘In the future, I just don’t see how this clock can be beaten,’ Dr Barrett said.

‘The properties mean that high accuracy can be achieved even in a wide range of environments.

‘The lutetium clock would be stable even if you went from the hottest place recorded on Earth in Death Valley to the coldest place in the Antarctic plateau.’

His team has spent over a decade doing precision engineering on its atomic clock setup and testing different properties of the atom.

The researchers not only calculated their estimate of the clock’s accuracy but verified it by comparing two lutetium clocks with each other.

The two clocks’ ticks matched to the 19th digit, which the team says is the most precise clock comparison ever performed.

Read More: Scientists create an atomic clock so precise it could redefine the second