Atomic clocks look set to be­come more pre­cise

Clocks us­ing a ne­glected atom may be­come the best time­keep­ers

All About Space - - Launch Pad -

A ne­glected rare-earth el­e­ment is be­ing used in a bid to cre­ate the most pre­cise clocks ever built. Physi­cists at the Na­tional Univer­sity of Sin­ga­pore have dis­cov­ered that lutetium (Lu) can be highly ef­fec­tive within op­ti­cal clocks since it is rel­a­tively in­sen­si­tive to changes in en­vi­ron­men­tal tem­per­a­ture, mean­ing op­ti­cal clocks would be able to run for longer.

Cur­rently, global time and the con­trol of GPS nav­i­ga­tion is largely car­ried out us­ing ce­sium atomic clocks, thanks to a de­ci­sion by the In­ter­na­tional Com­mit­tee for Weights and Mea­sures in 1967 to de­fine a se­cond as the amount of time it takes for a ce­sium atom to ab­sorb enough mi­crowave en­ergy to be ex­cited.

Op­ti­cal clocks have since emerged as be­ing 100-times more pre­cise, us­ing higher fre­quen­cies of vis­i­ble light rather than microwaves to ex­cite atoms. But while the atoms used are alu­minium or yt­ter­bium, lu­terium has been found to be more reliable in such kinds of atomic clocks. There's a chance it could de­tect dark mat­ter and dark en­ergy too.

"We have defini­tively shown that Lu is the least sen­si­tive to tem­per­a­ture of all es­tab­lished atomic clocks," says first au­thor

Kyle Arnold. “That will not only help to make a lab-based clock more ac­cu­rate, but also make clocks that come out of the labs more prac­ti­cal, al­low­ing them to op­er­ate in a wider range of en­vi­ron­ments.”

Atomic clocks are still most widely used, but op­ti­cal clock ac­cu­racy has been boosted ex­per­i­ments with lutetium

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