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.

Their results show that entangling atoms in this way could speed up the time-measuring process of atomic nuclei clocks, making them more precise than ever. In principle, a clock based on this new approach would lose just 100 milliseconds since the dawn of time itself.

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In this case, the team found entanglement made the measurement process roughly three times faster compared with clocks acting at the SQL.

That might not seem all that dramatic, but a speed boost could be just the thing we need to study some of the more subtle influences the Universe has on time.

“As the Universe ages, does the speed of light change? Does the charge of the electron change?” says lead researcher Vladan Vuletic from MIT.

“That’s what you can probe with more precise atomic clocks.”

It could even allow us to find the point at which general relativity falls apart, pointing to new physics that connects the defined curvature of space-time with the uncertain nature of quantum fields. Or allow us to better measure the fine time-warping characteristics of dark matter.

Source: Physicists Made an Insanely Precise Clock That Keeps Time Using Entanglement

Plants have the same variation in body clocks as that found in humans, according to new research that explores the genes governing circadian rhythms in plants.

The research shows a single letter change in their DNA code can potentially decide whether a plant is a lark or a night owl. The findings may help farmers and crop breeders to select plants with clocks that are best suited to their location, helping to boost yield and even the ability to withstand climate change.

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To investigate the genetic basis of these local differences, the team examined varying circadian rhythms in Swedish Arabidopsis plants to identify and validate genes linked to the changing tick of the clock.

Dr. Hannah Rees, a postdoctoral researcher at the Earlham Institute and author of the paper, said: “A plant’s overall health is heavily influenced by how closely its circadian clock is synchronised to the length of each day and the passing of seasons. An accurate body clock can give it an edge over competitors, predators and pathogens.

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The team studied the genes in 191 different varieties of Arabidopsis obtained from across the whole of Sweden. They were looking for tiny differences in genes between these plants which might explain the differences in circadian function.

Their analysis revealed that a single DNA base-pair change in a specific gene—COR28—was more likely to be found in plants that flowered late and had a longer period length. COR28 is a known coordinator of flowering time, freezing tolerance and the circadian clock; all of which may influence local adaptation in Sweden.

“It’s amazing that just one base-pair change within the sequence of a single gene can influence how quickly the clock ticks,” explained Dr. Rees.

The scientists also used a pioneering delayed fluorescence imaging method to screen plants with differently-tuned circadian clocks. They showed there was over 10 hours difference between the clocks of the earliest risers and latest phased plants—akin to the plants working opposite shift patterns. Both geography and the genetic ancestry of the plant appeared to have an influence.

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Source: Plants can be larks or night owls just like us