The new kilogram has finally arrived. Updates to scientists’ system of measurement went into force May 20, redefining the kilogram and several other units in the metric system. The revamp does away ...

It has been used as a standard unit of weight measurement since the time of the French revolution, based on the precise mass of a lump of metal held in Paris. But the kilogram may be about to be given ...

Out with the old — kilogram, that is. Scientists will soon ditch a specialized hunk of metal that defines the mass of a kilogram. Oddly enough, every measurement of mass made anywhere on Earth is tied ...