NEW DEFINITIONS ON WORLD METROLOGY DAY
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Scientists Adopt New Definitions for Units of Weight, Temperature on Global Metrology Day
- Scientists adopted new hyper-accurate definitions for units of weight, electricity and temperature derived from the universal laws of Nature on the occasion of Global Metrology Day.
- The new kilogram (unit of weight) and three other new base units – ampere (electric current), Kelvin (temperature) and mole (amount of substance such as atoms) – will now not be based on ‘physical artefacts’ but on ‘constants of nature’ (quantum standards).
- The change, sees one of science’s most influential objects;
- More precise measurement taken from a quantum ratio is replaced a metal cylinder used to define what a kilogram is.
- Instead of relating to the mass of a singular physical object, the kilogram will now be defined in terms of the Planck constant.
- The Planck constant is the ratio of a frequency of light, on the one hand, to the quantum energy of that frequency, on the other. Another way, it is 6.626 x 10-34 joule seconds.
- The Planck constant, combined with two quantum phenomena that allow for the creation of electrical power, can be used to calculate mass based on the equivalent mechanical power needed to displace it.
- Also new definitions adopted for;
- The ampere — the rate of electrical current flow.
- The kelvin — the base unit of temperature.
- The mole — the unit measuring the amount of a given substance.
- With countries across the globe saying goodbye to original kilogram (kg) by introducing redefined International System of Units (SI Units) on the World Metrology Day, India’s National Physical Laboratory (NPL) – country’s national measurement body – too adopted the new system and launched a campaign to create awareness among users on how the new kilogram and three other base units will work in the country without affecting their day-to-day works.
- Their values will never change and countries will not have to copy their internationally accepted prototypes.
- The kilogram is the last unit of measurement based on a physical object.
- “Le Grand K“, as the platinum-iridium object is known, stood as the world’s benchmark of the kilogram for nearly 130 years before a decision was taken in November to bring several units of measurement into the 21st century.
World Metrology Day:
- 20th of May, World Metrology Day was being celebrated.
- The theme for World Metrology Day 2019 is “The International System of Units – Fundamentally better”.
- World Metrology Day is an annual celebration of the signature of the Metre Convention on 20 May 1875 by representatives of seventeen nations.
- The original aim of the Metre Convention is the world-wide uniformity of measurement remains as important today as it was in 1875.