Scientists Develop an Optical Clock With Unprecedented Precision That Could Redefine Time

Scientists built a strontium clock that could redefine the second. Find out how this ultra-precise timepiece works and its potential uses in navigation and science.

Scientists have developed an extremely accurate clock that might lead to a new way of defining a second. This clock, known as a strontium optical lattice clock, is among the most precise timepieces ever made, capable of measuring time with accuracy up to 19 decimal places. To put this into context, if this clock were to run non-stop for 30 billion years, it would only lose about one second.

This significant advancement has been made possible through progress in optical clock technology. A study published in the journal Metrologia by researchers from the Chinese Academy of Sciences shows that this clock has achieved the precision necessary for the potential redefinition of the second in the near future.

How Time is Measured

In the past, a second was based on the movement of the Earth, but its rotation is not steady. In 1967, the second was redefined using the oscillations of cesium-133 atoms, with one second defined as 9,192,631,770 oscillations. Although this is very precise, cesium atoms have their limits, as they oscillate only around nine billion times per second.

Strontium atoms, on the other hand, oscillate approximately 700 quadrillion times per second. The team's clock meets the high level of precision needed for redefining the SI second. It is now one of three strontium clocks that have reached this level of accuracy, and for the new definition to become official, at least three such clocks must be operating in different institutions.

Future Redefinition

The General Conference on Weights and Measures (CGPM) meets every four years to consider updates to definitions like the second. A proposal for a new definition of the second is expected to be presented at the 29th meeting in 2030.

Potential Applications

The strontium clock could have various useful applications in science and technology. It could enhance measurements of Earth's gravitational field, help in dark matter research, and support the development of next-generation satellite navigation systems. Portable and space-based versions of this clock could also be created, offering a highly accurate global time standard and new opportunities to test fundamental physical laws.

This achievement marks a major advancement in the field of timekeeping. With advanced science and technology, these clocks have the potential to improve both scientific research and practical applications, from navigation to space exploration.