Will Kilogram’s Definition Change?



Kilogram, the internationally used unit of measurement for mass, is said to be changed in the near past. You must be wondering, whether or not the definition of kilograms has changed and why did it happen. Well, the news about the change in the definition of the kilogram is official and now been making waves all over the world. Undoubtedly, this announcement has changed a lot in the world of sciences but there are strong reasons for backing up this decision.

Recently, at the General Conference on Weights and Measures held at Versailles, France, representatives belonging to more than 60 nations agreed on a new definition for the kilogram. Through this vote, a scientist has redefined the kilogram for the 21st century to eternity. Here is a brief look at how and why the definition of the kilogram has changed:


The Old Definition of Kilogram

Since the past two decades, the definition of kilogram depended on a physical object – a platinum-iridium cylinder also called as ‘Le Grand K’. This cylinder is stored in a triple-locked vault in the International Bureau of Weights and Measures (BIPM) in France. According to what we have been hearing almost all our lives, this cylinder, weighed exactly a kilogram. A slight change in the cylinder would result in the change of the entire system of measurement.

History of Kilogram:

Also officially known as the International Prototype of the Kilogram (IPK), this cylinder’s mass has been used since the 19th century as a means of measurement for the kilogram (kg) – a fundamental unit of mass in the International System of Units (SI). Therefore, every measurement of mass or weight be in milligram, metric, pounds or ounces worldwide, depended entirely on the mass of the IPK. However, the cylinder has recently become exposed to misusage and identity threats despite the provision of full-proof privacy.

Why Changing the Historic Kilogram?

Although the old definition of kilogram seemed perfectly fine and well understandable by the current generation, it has been changed by keeping in view a number of factors including:

Upheaval of Duplicity Threats:

Le Grand K has set an international measuring standard for weights since 1889. Meanwhile, in some parts of the globe, several replicas of the object were made and sold out. These copies had slightly different versions and seemed to vary with time. For a unit like weight, any deflection in the accuracy of measurements meant a lot.

Improved Accuracy:

According to scientists, even the tiniest bit of change could cause unexplainable circumstances. They believed that the two reasons why this change had to happen. Firstly, all the copies around the world and the master Le Grand K had certain variations; their weight was not exactly the same. Secondly, the Le Grand K itself had trivial changes in its weight over the years. When it was measured in the 1980s, surprisingly, it weighed a few micrograms lesser than it should have.

What Does the New Definition Say?

From what we know so far, the kilogram is now tied to an ultimate feature of the universe; Planck’s constant. Plank’s Constant is actually a figure which is known to have come from quantum physics and describes the smallest possible unit of energy. Now, the value of weight will not depend on an inconsistent cylinder, but instead, it will be held up across space and time constants. Courtesy to the remarkable revelation of Albert Einstein that energy and mass are directly related to each other.

Higher Accuracy and Precision:

It took scientists a couple of experiments including measuring an object’s mass by counting on the force required to lift it using a watt balance. This exquisite weighing machine, that took years to build, is strong enough to meet BIPM’s high criterion for accuracy and precision.

Future Implications:

You might be wondering how things will fold in the future. This change in kilogram’s definition will definitely not affect your weighing scales. If you are expecting it to cut down a few kilos from your body weight, you are wrong. Instead of that, it will pave ways for research and practical applications involving immaculate measurements. We can only imagine how hard it must be for current scientists and coming generations to adapt with this rather complex definition of Kilogram which now involves a constant from quantum theory.


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