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Old Dusty Kilogram Swapped for Something More Stable: Scientists

It has taken years of work to fine-tune the new definition to ensure the switchover will be smooth.

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Kilogram
The International Prototype of the Kilogram (IPK) is pictured in Paris, France, in this undated photo obtained from social media. VOA

After years of nursing a sometimes dusty cylinder of metal in a vault outside Paris as the global reference for modern mass, scientists are updating the definition of the kilogram.

Just as the redefinition of the second in 1967 helped to ease communication across the world via technologies like GPS and the internet, experts say the change in the kilogram will be better for technology, retail and health — though it probably won’t change the price of fish much.

The kilogram has been defined since 1889 by a shiny piece of platinum-iridium held in Paris. All modern mass measurements are traceable back to it — from micrograms of pharmaceutical medicines to kilos of apples and pears and tons of steel or cement.

kilogram, weight
Border Security Force officials showing 17 kilogram heroine.

The problem is, the “international prototype kilogram” doesn’t always weigh the same. Even inside its three glass bell jars, it gets dusty and dirty, and is affected by the atmosphere. Sometimes, it really needs a wash.

“We live in a modern world. There are pollutants in the atmosphere that can stick to the mass,” said Ian Robinson, a specialist in the engineering, materials and electrical science department at Britain’s National Physical Laboratory.

“So when you just get it out of the vault, it’s slightly dirty. But the whole process of cleaning or handling or using the mass can change its mass. So it’s not the best way, perhaps, of defining mass.”

What’s needed is something more constant.

kilogram, weight
The Kilogram. Flickr

So, at the end of a week-long meeting in the Palace of Versailles, Paris, the world’s leading measurement aficionados at the International Bureau of Weights and Measures will vote Friday to make an “electronic kilogram” the new baseline measure of mass.

Just as the meter — once the length of a bar of platinum-iridium, also kept in Paris — is now defined by the constant speed of light in a vacuum, so a kilogram will be defined by a tiny but immutable fundamental value called the “Planck constant.”

The new definition involves an apparatus called the Kibble balance, which makes use of the constant to measure the mass of an object using a precisely measured electromagnetic force.

Paris,diesel,kilogram, weight
The kilogram has been defined since 1889 by a shiny piece of platinum-iridium held in Paris.VOA

“In the present system, you have to relate small masses to large masses by subdivision. That’s very difficult — and the uncertainties build up very, very quickly,” Robinson said.

“One of the things this [new] technique allows us to do is to actually measure mass directly at whatever scale we like, and that’s a big step forward.”

Also Read: NASA to Send Organ-on-Chips to Test Human Tissue Health in Space

He said it had taken years of work to fine-tune the new definition to ensure the switchover will be smooth.

But while the extra accuracy will be a boon to scientists, Robinson said that, for the average consumer buying flour or bananas, “there will be absolutely no change whatsoever.” (VOA)

Next Story

Scientists Find Solution to Reduce Air Pollution, Develop Smart Windows

The design could lay the foundation for next-generation flexible transparent smart windows that can reduce air pollution.

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Scientists, Air pollution
The design could lay the foundation for next-generation flexible transparent smart windows that can reduce air pollution. Pixabay

A team of Chinese scientists have developed a large-scale transparent smart window that can change light intensity while effectively capturing the particulate matter in smog, a study said.

The study published on Saturday in the journal iScience described a simple solution-based process to fabricate large-area flexible transparent windows with Ag-nylon electrodes for high-efficiency PM2.5 capture, reports Xinhua news agency.

It takes only 20 minutes to fabricate 7.5 square metres of Ag-nylon flexible transparent windows showing an optical transmittance of over 86 per cent, according to the group of scientists led by Yu Shuhong from the University of Science and Technology of China (USTC).

Scientists, Air Pollution Control
The scientists found that the obtained Ag-nylon electrodes could be used as an ideal intelligent thermochromic smart window with excellent mechanical stability. Pixabay

The Ag-nylon mesh can not only change the indoor light intensity, but also purify indoor air as a high-efficiency PM2.5 filter.

The scientists found that the obtained Ag-nylon electrodes could be used as an ideal intelligent thermochromic smart window with excellent mechanical stability.

It remains stable after undergoing a bending test with 10,000 bending cycles with a minimum bending radius of 2.0 mm.

ALSO READ: Scientists Develop A New Technique to Measure Blood Clot

Also, the Ag-nylon electrodes can remove PM2.5 by 99.65 per cent while remaining stable even after 100 cycles of PM filtration and a cleaning process, according to the study.

The design could lay the foundation for next-generation flexible transparent smart windows that can reduce air pollution. (IANS)