The Metrological and Applied Sciences University Research Unit (MeASURe) invites you to join them for a celebration of the launch of the Revised SI.  (including the retirement of the international prototype of the kilogram*)

The International System of Units, the SI, which is based on the second, the metre, the kilogram, the ampere, the kelvin, the mole and the candela (the base units), is being revised to update the definitions of four of these units. Revised definitions of the kilogram, ampere, kelvin and mole will be approved next Friday (16 November 2018) by the 26th General Conference on Weights and Measures (CGPM), the international body responsible for the global comparability of measurements.

Representatives from the National Metrology Institute of South Africa (NMISA) will be present and contributing to the event. The revised definitions will come into force internationally on 20 May 2019.

The revised definitions are based on seven physical constants (including the speed of light, the Planck constant, the Boltzmann Constant and the Avogadro constant) and are therefore inherently stable. The quantities have been chosen so that the revised definitions will not need to be modified to accommodate future improvements in the technologies used to realize them, and will have far-reaching benefits for innovations in industry, serving society and fostering science and research. In Max Planck’s visionary words in 1927, these units will “necessarily retain their validity for all times and cultures, even extra-terrestrial and nonhuman.”

Programme:
• Webcast of the open session of the 26th CGPM (12:00 to 14:30), including the talks:
− "A quantum basis for the SI" by Klaus von Klitzing,
− "The role of the Planck constant in physics" by Jean-Pierre Uzan,
− "Optical atomic clocks – opening new perspectives on the quantum world" by Jun Ye
− "Measuring with fundamental constants; how the revised SI will work" by Bill Phillips
• Spot quizzes (“How many boat lengths are there in a furlong?”)
• Prize for the best measurement joke (“What is the cleverest measuring device? A graduated cylinder!”)
• And a whole lot more yet to be thought of (thereby adding uncertainty to the event)