ABOVE: A copy of the cylinder of platinum-iridium that has been used to define the kilogram
WIKIMEDIA, NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY
Next Friday (November 16), representatives of 57 countries will assemble at a conference in Versaille, France, to vote on changing the definition of the kilogram, The Guardian reports. The proposed change is to define the kilogram in terms of Planck’s constant, which relates the energy of a photon to the frequency of its waves, rather than on a singular piece of metal.
It was France’s King Louis XVI who, in the late 1700s, got a group of scientists together to devise international units of measure. Out of this meeting, the kilogram—or at least the idea of a standard unit of mass—was born
For more than a century, the kilogram has been defined by the weight of a cylinder of platinum-iridium at the international bureau of weights and measures ...
