In a historic vote, nations on Friday unanimously approved a ground-breaking overhaul to the international system of measurements, uniting together behind new scientific definitions for the kilogram and other units.For more than a century, the kilogram has been defined as the mass of a cylinder of platinum-iridium alloy kept in a high-security vault in France. That artefact, nicknamed ‘Le Grand K,’ has been the world’s sole true kilogram since 1889. But now, the kilogram and all of the other main measurement units will be defined using numerical values that fit handily onto a wallet card.
Source : https://www.thehindu.com/todays-paper/tp-life/kg-gets-a-new-definition/article25522424.ece