Wednesday , March 29 2023

The counter and the kilogram will not be the same


Here is the turning point of the measure age from one meter to one kilogram: the old models will go to the attic, and the new ones will last forever. The new International Measurement System (OK) was approved: OK came from representatives of 62 countries gathered in Versailles at the General Conference on Weights and Measures (Cgpm) and the result was welcomed with a standing position ovation from the participants.

Delegates voted in favor of the new parameters that will come into force on May 20, 2019 and will redefine the seven units of measure: kilogram, meter, second, amp, kelvin, mole and candle. They will do it in terms of fundamental constants of physics, rather than physical objects that can change over time.

We are, for example, the kilogram of platinum-iridium preserved for 130 years in France in the Sèvres International Measures and Measures Bureau. "We are very happy because the whole system is innovative," said ANSA Maria Luisa Rastello, scientific director of the National Institute of Metrology Research (Inrim), the only member of the International Committee of Measures and Weights in Italy, who met in Versailles.

For the Nobel Prize for Physics, Bill Philips, "this is the biggest revolution of the measure." In practice, nothing changes for those who use the staircase every day, because a pound of apple will always weigh a pound, but it will change to ensure that units remain comparable and consistent across the world, and this business is essential, trade. Being inaccurate, a fraction of a second may not be important for cooking a food, but is essential in fast stock exchanges.

"The change, Rastello has noted, is necessary to ensure the stability of the system for a very long period of time, since it still has a material probability of kilo making the entire system very fragile." If the Sèvres lab had fired and "the kilos were destroyed or destroyed, the whole world would be left without reference to the table." An abstract concept such as the fundamental constants, instead, continued the expert, is available to anyone at any time without having to go to the "temples" where the references of the measures are kept. "It means we also have our pockets," said Philips.

In the new system, the kilogram will be defined according to Planck's constant, which connects the particles to their energy and therefore mass, the amperage that measures the electric current will rely on the charge of an electron.

A pure sphere of silicon will be the basis for redefining the size that measures the amount. Finally, kelvin, which refers to temperature, will be reformulated according to the Boltzmann constant, which establishes a connection between energy and temperature. All these measurements will be combined with the counter, the second and the candles, which measure the brightness, which has already been redefined in this way.

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