The Quantum Reform of the Modern Metric System: Mass becomes quantum, and electrical measurements become honest.
Professor William D. Phillips, Physicist, College Park Professor of Physics and IPST, Distinguished University Professor, and Nobel Prize Winner
Tuesday, October 22, 2024 at 4:00 p.m. (Light refreshments at 3:30 p.m.)
1101 A. James Clark Hall, University of Maryland College Park
Photo by: Robert Rathe
Abstract: The modern metric system, officially known as the International System of Units (SI), has recently undergone its most revolutionary change since the inception of the metric system at the time of the French revolution. The kilogram, ampere, kelvin, and mole all have new definitions, based on fixing the values of fundamental constants of nature. Famously, the reform eliminates the artifact International Prototype Kilogram as the foundation of the unit of mass. This lecture will explain why this was necessary and how it was accomplished. Less famously, the century-old practice of having two separate unit systems for electrical metrology —“legal” and “scientific”— has disappeared with the reformed SI.
Biography:
William Phillips is a Distinguished University and College Park Professor of Physics. In 1997 he was a co-recipient of the Nobel Prize of Physics "for development of methods to cool and trap atoms with laser light."
Professor Phillips received his B.S. in 1970 from Juniata College and his Ph.D. from the Massachusetts Institute of Technology. He is a Fellow of the American Physical Society, a Fellow and Honorary Member of the Optical Society of America and a Member of the National Academy of Sciences.
His research interests included: laser cooling and trapping of neutral atoms; quantum information with single-atom qubits; atomic-gas Bose-Einstein condensates; atoms in optical lattices; atomic physics analogs of condensed matter systems; coherent deBroglie-wave atom optics; and collisions of ultracold atoms.
Paint Branch is a 14-mile stream that brings water from small streams and tributaries throughout the region, flowing south through our campus on its way to the Anacostia River. Many of us pass it by car, bicycle, or on foot each day on our way to and from work. Like the Paint Branch, we anticipate that this new lectureship will serve as a confluence that draws together the many talented and active researchers, faculty, and students in applied physics in our community and will remind us of our common goals and principles.
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