The Ministry of Science and Technology announced that in collaboration with many countries, China has successfully developed a cesium atom fountain clock. China's new cesium atomic frequency standard will lose less than 1 second every 6 million years. Previously the standard was set to lose 1 second every 300 thousand years.
The cesium atom fountain clock is extremely precise and the structure is very complicated. Only a small number of countries including France, the US and Germany have built such clocks, which help to define Coordinated Universal Time (UTC).
By People's Daily Online