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ASD Colloquium Series

April

16

“For all times, For all people” the eternal quest for universal measures
Jon Pratt (NIST)

The International System of Units, or SI, will undergo a profound change on World Metrology Day, May 20, 2019. From that day forward, more than 60 countries accounting for 98% of global GDP have agreed that all standards of measure will be derived from a collection of fundamental quantities and constants. These quantities include the hyperfine splitting frequency of a Cesium atom, the speed of light, the quantum of action, the fundamental charge, and the Boltzmann and Avogadro constants, all of which are now accepted as fixed, physical invariants of the universe, having exact numerical values in terms of our existing units of measure. This audacious move shuns physical standards to embrace completely conceptual references teased from the standard model of physics. The move would no doubt have pleased the originators of the metric system, who were striving for nothing less than to “sign up the universe”, as Napoleon derisively mocked in his memoirs. “For all times, For all people” was the rallying cry in 1790, and in this talk I will examine some of the historical, philosophical, and technical aspects of this pivot point for humanity, when measurement might be released from earthly limitations to become truly universal.

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ASD Colloquia are Tuesdays at 3:45 pm (Meet the Speaker at 3:30 pm) in Bldg 34, Room W150 unless otherwise noted.

 
Date April 16, 2019
Start/End Time 03:45 PM - 05:00 PM
Location B34, W150
Website https://science.gsfc.nasa.gov/660/seminars/ASDcolloq/index.html
Contact Knicole Colon
Email Address knicole.colon@nasa.gov
Event Type Seminars/Colloquia
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