The SI (or Système
International d'Unités
)
is the modern form of the metric system.
The metric system was originally established after the
French Revolution as a consistent set of decimal units
with base units that could be precisely determined by reference to standards (a platinum metre stick and a platinum
kilogram mass kept in Sèvres,
France).
The SI (officially established in 1960) differs from older versions of the metric system in the number of base units and in the way these base units are defined. For example, the older CGS system was based on centimeters, grams, and seconds; the modern SI is based on meters, kilograms, seconds, kelvins, moles, amperes, and candelas.
Author: Fred Senese senese@antoine.frostburg.edu