Four days ago, scientists and diplomats who gathered at an auditorium in Versailles, France, changed the global trade and technology forever in a jiffy by voting together for heralding a new system that completely upends the historical methods for establishing the standards using physical objects. That was a 'weighty' day and the announcement was a ‘weighty’ one. 

Since the 19th century, scientists have based their definition of the fundamental unit of mass - a shining platinum iridium cylinder stored in a locked vault in the bowels of the International Bureau of Weights and Measures (BIPM) in Sevres, France, called 'Le Grand K’. A kilogram was equal to the heft of this aging hunk of metal, and the cylinder, by definition, weighed exactly a kilogram. If the cylinder changed, even a little bit, then the entire global system of measurement had to change, too. 

With last Friday's vote, scientists have redefined the kilogram for the 21st century by tying it to a fundamental feature of the universe - a small, strange figure from quantum physics known as Planck's constant, which describes the smallest possible unit of energy. The current redefinition is the result of a decades-long, worldwide quest to measure Planck's constant precisely enough that the number would stand up to scientific scrutiny. Though the newly defined kilogram won't affect our bathroom scale, it will have practical applications in research and industries that depend on meticulous measurement. Le Grand K has been at the forefront of the international system of measuring weights since 1889. There are also several close replicas. But the master kilogram's days are over now as wear and tear could change its mass. 

When it was weighed in 1980s, it weighed several micrograms less. In a world where accurate measurement is critical to many areas, such as in drug development, nanotechnology and precision engineering, those responsible for maintaining the system thus planned to overturn Le Grand k's increasingly flawed rule. The evolution of the international system of units was a must for the society. The system which has its origins in the heady days of the Enlightenment, was meant to end the bickering over the number of Spanish 'vara' in a British furlong and ease the anxieties of a merchant who bought goods in the Netherlands, where the weight was based on the amount of fish that could fit in a ship's hold and sold them in France, where weight was tied to the heft of a wheat grain. 

“For all times and for all people” was the motto of this standard unit. But with the progress of science everything keeps changing and this happened to weight also. Anyway, all these efforts are just an acknowledgment of an immutable truth that the nature has laws to which all of us are subject. This is just one more step toward a lofty dream that, in understanding nature's laws, scientists can help build a better world. The new unit will now be entirely stable liberating science and industry from their reliance on centrally maintained mass standards. RIP Le Grand K.

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