Redefine Time with an Element

Redefine Time with an Element

According to a recent research, the definition of second might change as there is sufficient room for improvement.

Time is an important commodity of our lives as we plan our routines in accordance to it. Clocks come to our assistance in this regard as they continuously inform us about the current time. The most precise clocks that we have today are so accurate that they show a deviation of only one second in about 300 million years.

This means that the clock that began its operation in the era of dinosaurs has not gone off by even a second till date. Having said that, scientists are still not happy with that and claim that the accuracy of clocks can be improved by making use of Lutetium, a rare-earth element that is hardly used by humans these days.

When humans started to measure time, one second was defined as a fraction of the solar day. This meant that 1 second was equal to 1/86400 (24 hours * 60minutes * 60seconds) of an entire day as Earth takes 24 hours to spin around its axis. This technique lacked accuracy because the rotation of Earth is not ideal. In order to counter that, scientists made a massive change to the timing scale. Instead of calibrating our clocks with respect to heavens, they took help from atoms, the invisible building blocks of matter. The International Committee for Weights and Measures redefined a second in 1967.

According to that, the time taken by a Cesium atom to absorb enough energy to get excited is equal to one second. In case you are wondering what ‘excited’ means, it is a state where electrons of an atom jump from an energy level to the next. This is easier said than done as it took researchers three years to figure out that an atom of Cesium must be pulsed with exactly 9,192,631,770 cycles of microwave radiation in order to excite it. The frequency of microwaves needed to excite Cesium atoms was measured to achieve this conclusion.

Global time and GPS navigation systems are still using these atomic clocks but Optical Clocks have made some serious progress in the past decade or so. They are 100 times more efficient than their Cesium counterparts. Their working mechanism is very much similar to the Cesium clocks but they use either Aluminium or Ytterbium. These elements get excited when high frequencies of visible light are radiated at them. The speed of visible light is faster than the microwaves and this results in a much precise measurement of time.

However, the stability factor of an optical clock is not desirable at all. Similarly, it is inconsistent as its results are heavily dependent on the environment. Murray Barrett, an Associate Professor of Physics at the National University of Singapore, told the world that Cesium clocks are still preferred as they are reliable. He said,

“Cesium Clocks are still much more reliable in their implementation than [the new] optical clocks.”

The team of Barrett conducted a recent study in which they realized that Lutetium, a silvery-white metal having 71 protons inside its nucleus, is less sensitive to environmental changes than Aluminium and Ytterbium. It solves another important problem which is known as ‘Micromotion Shift’.

As the atoms used in these clocks are charged, they react (back and forth movement) to the electromagnetic fields created by visible light or microwaves. This generally skews the measurement of time. Having said that, a specific type of Lutetium ion has a natural property that allows it to avoid this shift.

Jerome Lodewyck, a Physicist at Paris Observatory, pointed out a disadvantage of using these ions. He mentioned that those atoms will become more sensitive to the environmental conditions like temperature. He further said that this trade-off might affect the impact of this latest discovery. As a result, he declared that Lutetium might not be the real game changer. Despite all that, he acknowledged the efforts of Barrett’s team and mentioned that this high-quality work will provide the scientists with another alternative option to produce atomic clocks.

On the other hand, Barrett himself agreed that Cesium clocks are doing absolutely fine for now but optical clocks will hold the key for highly precise applications. He thinks that we must move gradually in order to attain best possible results.

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