Chinese physicists have revealed that they successfully operated a cold atomic clock in space in a paper published in the journal Nature Communications on July 24.
World's First Cold Atomic Clock To Work In Space
Scientists from the Chinese Academy of Sciences officially announced that they successfully operated a cold atomic clock aboard the now-defunct Chinese space lab Tiangong-2 for more than 15 months. The clock was launched into space in September 2016.
"It is the world's first cold atomic clock to operate in space ... it will have military and civilian applications," said Xu Zhen, a scientist who was involved in the atomic clock project
Cold Atomic Clocks
Atomic clocks are far more accurate than conventional clocks, some would take billions of years to drift off by a second. They are used to conduct sensitive experiments as well as calibrate electronics used by global positioning systems.
Cold atomic clocks work by laser-cooling atoms to almost absolute zero before their oscillations are measured. These clocks are more precise since the ticks are more consistent at very low temperatures. The vibrations of the atoms are also measured while they are in free fall so they do not interact with anything else.
On Earth, this means that the atoms need to be nudged up so that they can be measured while they are falling through a detector.
Sending A Cold Atomic Clock Into Space
China hoped that deploying the cold atomic clock into space and freeing the atoms from gravity will provide more accurate time than other atomic clocks.
The researchers acknowledged the difficulty involved in making such a device work in orbit since it needs to be smaller compared with its counterparts used on Earth. It also has to pass safety tests needed for launch into space, has protection against cosmic radiation, and work in microgravity sans the presence of quantum physicistS to make adjustments in case anything goes wrong.
The researchers nonetheless said that space-bound cold atomic clocks have several advantages. Sending cold atomic clocks to space provides scientists opportunity to study atomic oscillations over longer periods since atoms can stay in place longer in microgravity, which would provide a longer period of measurement.
"Deploying such cold atom clocks (CACs) in space is foreseen to have many applications," the researchers wrote in their study. "The demonstration of the long-term operation of cold atom clock in orbit opens possibility on the applications of space-based cold atom sensors."
