Base units and standards: a new approach

Base units and standards: a new approach By international agreement, there presently are seven base units: meter, second, kilogram, ampere, kelvin, mole, and candela. Each of them is uniquely defined and given a standard more or less easy to handle. Considerable progresses of modern physics suggest to use major universal constants as fixed exactly without unit, for example the speed of light. Consequently, a new system might be set up: only the second would keep its statute of base unit while the meter, the kilogram, the volt and the kelvin would become derived units and would not need to be referred any longer to a standard. Nevertheless the mole raises a particular problem.