TEMPO.CO. Jakarta – On November 16, the General Conference on Weight and Size – by scientists in the world will begin in France. At the conference, scientists will choose to change the definition of kilograms, which is associated with the eternal phenomenon of nature: Planck's constant, as reported by CNET, November 14, 2018.
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The most commonly used form of measurement in the world is based on the metric system and is officially known as the International Unity System (SI). There are seven "base units" including amps, seconds and molecules.
Some of these measurements were defined by physical phenomena, such as seconds, based on the rotation of the Earth. Now the seconds are defined by the radiation period in the cesium atom 133.
Kilogram is the last base unit associated with a physical object. The physical object is a piece of metal that is constantly stored underground at the International Weight and Size Bureau of Sèvres, France.
Also, the platinum-iridium alloy, also known as the Prototype of the International and Informal Kilogram as Le Grand K, is like a ring in Lord of the Rings. Each weight is calibrated to Le Grand K, standardizing the measurement of one kilogram worldwide.
But Le Grand K, which was faked in 1889, lost 50 micrograms in the last 129 years. The kilogram became "999.99995 grams". Despite the loss of a small part of his mass, the pounds are still defined by Le Grand K, which changes over time, and scientists do not like it.
"This is good when measuring sugar sacs, but it becomes unacceptable for a more sophisticated science, such as measuring drug doses," a National Physical Lab (NPL) Statement quoted CNN .
So one kilogram can be determined by a universal phenomenon unchanging known as Planck's constant, rather than a piece of metal in the basement. But how does it work?
This is defined by taking a fixed numerical value from the Planck constant to 6,626,070 15 x 10-34 expressed in units of Js, which is equal to kgm2s-1, where the counters and droplets are defined in terms c and vCs.
Planck's constant is a phenomenon in quantum mechanics that allows mass to be associated with electromagnetic energy. This is one of the smallest dimensions of the physical world and the finding that it is a great challenge. The journey lasted for decades and involved a machine known as the Kibble equilibrium that tried to equalize energy, not mass.
"We found ourselves at an important time on our journey," said Dr. Barry Inglis, CEO of Australia's National Measurement Institute. "After years of research, it is now possible to justify the main revisions of the SI. This decision, if taken, will represent significant scientific achievements."
The most important for kilograms, Planck's constant is just that: constant. Unlike Le Grand K, there will be no more than 50 micrograms in 129 years.
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CNET | CNN