American researchers build most accurate, precise atomic clock in world

American researchers build most accurate, precise atomic clock in world

The clock is accurate enough to detect the effects of gravity at a microscopic scale, and demonstrates that a more precise definition of a second is possible.

The most accurate clock in the world. (Image Credit: K. Palubicki/NIST).

New Delhi: American researchers have developed the most precise and accurate clock in the world, that transcends everyday timekeeping. The next-generation optical atomic clock demonstrates that it is possible to update the definition of the second, something that the global scientific community is considering. Existing atomic clocks measure a second by shining microwaves on atoms. The next-gen clocks illuminate atoms with optical light, which have a higher frequency, to measure a second more precisely. Optical clocks are expected to deliver much higher accuracy for international timekeeping, losing a second every billion years.

A paper describing the findings has been accepted for publication in Physical Review Letters. One of the authors of the study, Jun Ye says, “If we want to land a spacecraft on Mars with pinpoint accuracy, we’re going to need clocks that are orders of magnitude more precise than what we have today in GPS. This new clock is a major step towards making that possible. We’re exploring the frontiers of measurement science. When you can measure things with this level of precision, you start to see phenomena that we’ve only been able to theorize about until now.”

Telling time with a web of light

The new atomic clock uses an optical lattice to trap and simultaneously measure tens of thousands of individual atoms, with the precision of the measurement increasing with the number of atoms measured. Compared to previous optical lattice clocks, the new design uses a shallower lattice, reducing major sources of error from laser light that traps the atoms, as well as atoms interacting with each other in a tight space.

Clocking relativity on microscopic scales

The clock is precise enough to measure subtle effects predicted by theories such as general relativity, on a microscopic scale. One of the key predictions of Einstein’s theory of general relativity is that gravity influences time, with time passing slower in stronger gravitational fields. Researchers can discern tiny changes in the flow of time caused by gravity by raising or lowering the clock on a submillimeter scale, about the thickness of a single human air. This atomic clock can potentially pave the way of reconciling physics of the quantum realm with large-scale phenomena described by general relativity, an endeavour that eludes scientists despite decades of attempts.