According to an April 21 Discovery online news report, scientists believe that the strontium (atomic) clock has gotten so precise and stable that it will neither gain nor lose a second for the next 15 billion years.
The strontium clock, which is about three times as precise as the previous record holder, now has the power to reveal tiny shifts in time predicted by Einstein’s theory of relativity, which states that time ticks faster at different elevations on Earth. That precision could help scientists create ultradetailed maps of the shape of the Earth.
In the Discovery online report, atomic clocks typically work by measuring the vibrational frequency of atoms, such as strontium or cesium, as the atoms jump between different energy levels. Every atom naturally oscillates at very high frequencies billions or trillions of times per second.
“Our performance means that we can measure the gravitational shift when you raise the clock just 2 centimeters (0.79 inches) on the Earth’s surface,” study co-author Jun Ye, a physicist at JILA, a joint institute of the National Institute of Standards and Technology and the University of Colorado, Boulder, said in a statement.
Scientists believe that counting these regular beats provides a highly precise measure of time. Currently, a cesium clock at NIST defines the second, where 1 second is 9,192,631,770 oscillations of the cesium atom. In the new clock, thousands of strontium atoms at extremely cold temperatures are essentially pinned into a narrow column by intense laser light. In the new clock, thousands of strontium atoms at extremely cold temperatures are essentially pinned into a narrow column by intense laser light.