Old Kilo finally retired after 130 years:Justifying the introduction of a new standard kilogram and commencing a new measurement phase.
The Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig, Germany, is leading the charge in making measuring even more accurate. At the helm of this esteemed institution is Cornelia Denz, its president.
For centuries, the kilogram, a cylinder made of platinum and iridium, has been the most accurate "one kilogram" in the world. However, over a period of 130 years, it has lost 50 micrograms in weight. This minor yet significant loss led to the redefinition of the kilogram in 2019.
The original kilogram, now no longer the primary kilogram reference, is stored in a high-security vault in the International Bureau of Weights and Measures (BIPM) in Paris. Germany, due to historical entanglements, has three copies of the original kilogram. Comparisons between the original kilogram and the German copies have been made in the past.
The new primary kilogram reference is an electromagnetic balance. This innovative reference, developed by an international team of scientists led by the BIPM, is more precise than the original kilogram. The new kilogram references are in healthy competition, pushing the boundaries of measurement accuracy even further.
One of the new kilogram references was recently received in Germany. The second method for this new reference could potentially measure how many micrograms the original kilogram loses per second. This method involves counting atoms within an atomic lattice, leading to a kilogram reference that exactly corresponds to one kilogram.
The second new primary kilogram reference is a nearly perfect silicon sphere. This cutting-edge reference is used in Brunswick, Germany, contributing to Germany's ongoing commitment to measurement precision.
For those interested in learning more about this fascinating topic, an audio discussion titled "Worn Out! How to Save the Kilogram" is available at a specific link. This discussion delves deeper into the challenges faced and solutions found in the redefinition of the kilogram.
