Researchers, including an Indian-origin scientist, are working on a highly accurate atomic clock the size of a Rubik's cube, measuring about 2 inches in each dimension.
The clock can be used to keep time in places where conventional clocks do not work like underwater or in war zones, the team from the Massachusetts Institute of Technology (MIT) revealed.
"We are trying to make something that would fit in, say, a Rubik's cube, and be stable over a day or a week," said co-author Krish Kotru, a graduate student in MIT's department of aeronautics and astronautics.
Submarine crews or deep-sea divers may even be able to use these highly accurate clocks underwater.
"Furthermore, soldiers on the battlefield could use the devices even if satellite signals are jammed," Kotru was quoted as saying in a LiveScience report.
Some miniaturised versions of such atomic clocks, known as chip-size atomic clocks (CSACs), are available in the market.
But they sacrifice a lot of the preciseness of conventional atomic clocks, researchers said.
Like other atomic clocks, the MIT prototype keeps time by measuring the natural vibration, or oscillation, of cesium atoms in a vacuum.
"We have a path toward making a compact, robust clock that is better than CSACs by a couple of orders of magnitude and more stable over longer periods of time," Kotru noted.
