Chinese Scientists Seek To Redefine Second With New Ultra-Precise Clock

Scientists in China have developed an extremely precise clock that could change the measurement of time. According to South China Morning Post (SCMP), the optical clock loses or gains one second every 7 billion years, bringing scientists closer to redefining the second as a basic unit of time. The new clock uses ultra-cold strontium atoms and powerful laser beams for stability in measuring time. This makes China only the second country in the world after the US to achieve such precise timekeeping, the SCMP report further said.

The ground-breaking research was published in the peer-reviewed journal Metrologia earlier this month. The research team was led by physicist Pan Jianwei.

The team said that their research opens up new opportunities to test fundamental physics theories, detect gravitational waves and search for dark matter.

The team also said that the clock has a stability and uncertainty under 5 quintillionths.

The current record holder is the optical clock hosted by the University of Colorado in Boulder. It was developed by a group led by Chinese-American physicist Jun Ye.

Optical clocks are considered more precise in measuring time because they use laser light at a frequency of around 500 THz, which is adjusted to precisely match the narrow atomic resonance of particular quantum transitions of atoms such as strontium, ytterbium, and mercury, among others, according to American Physical Society.

These devices can significantly enhance the precision of global navigation satellite systems, and help build highly secure communication networks based on quantum key distribution.

Till now, the second is defined on the basis of microwave fountain clock, a type of atomic clock. But its precision is limited by the microwave frequency standard. Scientists find optical clocks better and precise than the atomic clocks.