An atomic clock that sets the time by the tiny oscillations of strontium atoms is so precise that it will neither gain nor lose a second for the next 15 billion years.
The new strontium clock, which is 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 now help scientists create ultra-detailed maps of the shape of the Earth. In a concept known as gravitational time dilation, time passes more quickly in weaker gravitational fields, so the higher the altitude on Earth, the lower the gravity is there, and the faster time is passing. The current clock is so sensitive that it could detect these effects with elevation changes as little as that caused by putting a small book under the clock.
As strontium atoms beat at 430 trillion times per second, theoretically there’s room for even more improvement in accuracy.
If the clock can improve further, that would enable even more detailed measurements of the Earth’s shape and mapping at a level hitherto unimaginable.
Even at the current accuracy level the usefulness of the resultant maps are widespread and will no doubt prove very significant in helping researchers track and understand global impacts associated with climate change.