Scientists have created an atomic clock that is so precise that it can detect tiny changes in the speed of its ticks depending on whether it is 2 centimeters closer or farther from the center of Earth.
"Time can be intricately connected to gravity," said Jun Ye, a physicist at JILA, a joint institute of the National Institute of Standards and Technology and the University of Colorado, Boulder. "It sounds like science fiction, but these measurements are a reality."
The ability of a hypersensitive clock to determine small differences in altitude is based on Einstein's prediction that the farther one gets from the center of an attractor (like Earth), the faster time moves.
Researchers have long ago proved this theory by comparing the speed of clocks separated by vast differences. Five years ago researchers at NIST created a clock so sensitive that it could detect the difference in time between two elevations just a foot from each other. But the new clock is even better.
"Now when we measure this very weird property of time fabric in the laboratory, even a 2-centimeter change will result in a detectable time change in the clock," Ye said.
Los Angeles Times
