A new kind of atomic clock possibly reveal new physics
The design, which uses entangled atoms, could help scientists detect dark matter and study gravity’s effect on time.
Atoms are trapped in an optical cavity composed of two mirrors. When a “squeezing” laser is set through the cavity, the atoms are entangled, and their frequency is measured with a second laser, as a platform for more precise atomic clocks.
Credits: MIT scientists
MIT scientists have designed a new kind of atomic clock that could answer some mind-boggling questions, such as what effect gravity might have on the passage of time and whether time itself changes as the universe ages.
Improved atomic clocks could help scientists determine what impact gravity has on time on December 17, 2020, 14:23
In context: Modern atomic clocks are pretty darn precise – so much so, in fact, that their accuracy is measured in terms of the lifespan of the entire universe. One such example, the strontium atomic clock, is so accurate that had it started running at the beginning of the universe, it wouldn’t have gained or lost one second if checked today.
But as with most things in life, there’s always room for improvement.
Physicists at the Massachusetts Institute of Technology have designed a new type of atomic clock that measures entangled atoms instead of a cloud of randomly oscillating atoms.
If left to run for some 14 billion years roughly the current age of the universe a new type of atomic clock could keep accurate time to within a tenth of a second.
The design by US experts makes use of a bizarre phenomenon called quantum entanglements, in which particles become inextricably linked.
This entanglement, the researchers explained, helps reduce the uncertainty involved in measuring the oscillation of atoms used by atomic clocks to keep time.
The clock could be used to help reveal the elusive dark matter thought to make up more than three-quarters of the universe and to study gravity s effect on time.
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Atomic clocks are the most precise timekeepers in the world. These exquisite instruments use lasers to measure the vibrations of atoms, which oscillate at a constant frequency, like many microscopic pendulums swinging in sync. The best atomic clocks in the world keep time with such precision that, if they had been running since the beginning of the universe, they would only be off by about half a second today.
Still, they could be even more precise. If atomic clocks could more accurately measure atomic vibrations, they would be sensitive enough to detect phenomena such as dark matter and gravitational waves. With better atomic clocks, scientists could also start to answer some mind-bending questions, such as what effect gravity might have on the passage of time and whether time itself changes as the universe ages.
Physicists Made an Insanely Precise Clock That Keeps Time Using Entanglement
16 DECEMBER 2020
Nothing keeps time like the beating heart of an atom. But even the crisp tick-tock of a vibrating nucleus is limited by uncertainties imposed by the laws of quantum mechanics.
Several years ago, researchers from MIT and the University of Belgrade in Serbia proposed that quantum entanglement could push clocks beyond this blurry boundary.
Now, we have a proof of concept in the form of an experiment. Physicists connected together a cloud of ytterbium-171 atoms with streams of photons reflected from a surrounding hall of mirrors and measured the timing of their tiny wiggles.