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,
Radioactivity (song) the original does not offer a value judgement on the safety of radioactivity, the 1991 version drops all references to radio and incorporates additional lyrics with a pointed anti-nuclear theme, remaking the central lyrical hook as "stop radioactivity" and also referring to "contaminated population" and mentioning by name Chernobyl, Harrisburg (Three Mile Island), Sellafield and Hiroshima. "Radioactivity" has remained a regular part of Kraftwerk's live sets over the years. On its original performances in 1976, the band tried out an experimental light-beam operated "percussion cage", where Wolfgang Flür attempted to trigger electronic drum sounds by interrupting light beams using arm