👍 Smaller than a matchbox, more accurate than 30,000 years. China created the world's smallest atomic clock

Imagine a clock that won't lose a second in 30,000 years. Now imagine it fits in a case just 2.3 cubic centimeters in volume - smaller than a matchbox.

Chinese scientists from Wuhan University have created the world's most miniature atomic clock and have already launched it into mass production.

The new device is seven times more compact than leading American counterparts. Inside is a tiny chamber with rubidium vapor and a laser that creates an ultra-stable frequency.

This approach (coherent population trapping, or CPT) eliminated the need for bulky microwave resonators.
Why are atomic clocks so accurate? They use not the oscillation of quartz (as in ordinary clocks), but the fixed frequency of electron transitions in cesium, rubidium, or hydrogen atoms.

This frequency is stable to 15 decimal places. But previously, this required cabinets the size of a refrigerator. Chinese scientists managed to reduce the system to a volume of 2.3 cm³, maintaining accuracy of 30,000 years without error.

Compare: quartz clocks err by 1 second per month)

👉 Seven times smaller than American ones. We marvel at the link