History of the metric system levels of the krypton 86 atom as the new standard for the metre. The standard metre artefact was retired. In 1960, Giorgi's proposals were adopted as the basis of the "Système International d'Unités" (International System of Units), the SI. This initial definition of the SI included six base units, the metre, kilogram, second, ampere, degree Kelvin and candela, and sixteen coherent derived units. The evolution of the SI after its publication in 1960 has seen the addition of a seventh base unit, the "mole", and six more derived units, the "pascal" for pressure, the "gray", "sievert" and "becquerel" for radiation,
Strontium unit to have three to four strontium units. The strontium unit was formerly known briefly as the sunshine unit, a term promoted by the United States Department of Defense until public ridicule brought about its disuse. (Among the sources of this outcry was a George Carlin performance, released on the CD "", during a passage on governmental euphemisms for dangerous or unethical activities: "The Pentagon actually measures nuclear radiation in something they call 'sunshine units'!") Strontium unit The strontium unit is a unit used to measure the amount of radioactivity from strontium-90, a radionuclide found in nuclear fallout, in a subject's